Head-to-head comparison

Claude Opus 4.6 vs. GPT-6 Astra

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series: 30
distinct benchmark metrics: 8
latest retrieval: 2026-10-19

First modelSecond model

Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for Claude Opus 4.6 and GPT-6 Astra
Attribute	Claude Opus 4.6	GPT-6 Astra
Provider	Anthropic	OpenAI
Released	Feb 2026	Sep 3, 2026
Availability	Active	Limited access
Model type	Proprietary	Proprietary
Parameters	Not published	Not published
Architecture	Not published	Not published
Context window	1,000,000 tokens	1,050,000 tokens
Knowledge cutoff	May 2025	April 30, 2026
Technical sources	Model, Context	Model, Context

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for Claude Opus 4.6 and GPT-6 Astra
Price type	Claude Opus 4.6	GPT-6 Astra
API input	$5	$10 ≤272K / $20 >272K
API output	$25	$50 ≤272K / $75 >272K
Cache read	$0.5	$1 ≤272K / $2 >272K
Cache write (5 min.)	$6.25	$12.5 ≤272K / $25 >272K
Cache write (1 hr.)	$10	Not listed
Price verified	09/22/2026 Source	09/22/2026 Source

Claude Opus 4.6GPT-6 Astra

API inputUSD per 1M tokens, base tier

Claude Opus 4.6$5

GPT-6 Astra$10

API outputUSD per 1M tokens, base tier

Claude Opus 4.6$25

GPT-6 Astra$50

Cache readUSD per 1M tokens, base tier

Claude Opus 4.6$0.5

GPT-6 Astra$1

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for Claude Opus 4.6 and GPT-6 Astra
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
Claude Opus 4.6	Anthropic	Direct from developerStandard API	Lowest listed price: $5	Lowest listed price: $25	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Anthropic	Via OpenRouteranthropic	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Azure	Via OpenRouterazure/global	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Claude Platform on AWS	Via OpenRouterclaude-on-aws	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/europe	$5.5	$27.5	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/global	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
GPT-6 Astra	OpenAI	Direct from developerUp to 272,000 context tokens	$10	$50	Source09/22/2026
	OpenAI	Direct from developerAbove 272,000 context tokens	$20	$75	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us-west-2	$11	$55	Source10/26/2026
	Azure	Via OpenRouterazure	$10	$50	Source10/26/2026
	Azure	Via OpenRouterazure/us	$11	$55	Source10/26/2026
	OpenAI	Via OpenRouteropenai	$10	$50	Source10/26/2026
	OpenAI	Via OpenRouteropenai/fast	$20	$100	Source10/26/2026
	OpenAI	Via OpenRouteropenai/flex	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	OpenAI	Via OpenRouteropenai/ultrafast	$60	$300	Source10/26/2026

Benchmark index

Benchmark index compared

The index combines independent benchmarks on a scale from 0 to 100. A lead only counts when a model comes first in at least 95% of 200 recalculations with randomly redrawn test families. Otherwise both count as level.

Open the AI leaderboard

Claude Opus 4.6

Overall index

No overall score yet

GPT-6 Astra

Overall index

90.0

GPT-6 Astra leads in 3 of 5 shared areas. 2 areas are tied.

Area	Claude Opus 4.6	GPT-6 Astra
Coding	43.8	93.4
Agents	48.0	83.7
Financetied	72.9	71.9
Legaltied	71.5	78.9
Health	63.0	83.8

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

Not enough directly matched categories for a reliable radar

Only 2 of at least 5 categories have comparable, direct model measurements. The benchmark tables below show the available evidence without filling missing axes.

Claude Opus 4.6GPT-6 Astra

AA-Omniscience AccuracyOverall. Higher is better. No documented setup difference

Claude Opus 4.647.0%

GPT-6 Astra62.6%

AA-Omniscience Hallucination RateOverall. Lower is better. No documented setup difference

Claude Opus 4.662.8%

GPT-6 Astra51.3%

LMArena Code Arena WebDevOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.61,537.258

GPT-6 Astra1,780.244

LMArena Vision, Style ControlOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.61,294.46

GPT-6 Astra1,285.988

MedCodeOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.648.244 %

GPT-6 Astra48.486 %

MedScribeOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.686.738 %

GPT-6 Astra87.908 %

MMMU-ProOverall. Higher is better. No documented setup difference

Claude Opus 4.675.4%

GPT-6 Astra86.9%

Vibe Code Bench v1.1Overall. Higher is better. Test setup not documented as identical

Claude Opus 4.657.573 %

GPT-6 Astra89.594 %

LMArena Code Arena WebDevOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.61,546.362

GPT-6 Astra1,780.244

LMArena Vision, Style ControlOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.61,299.232

GPT-6 Astra1,285.988

LMArena Code Arena WebDevImage to webdev. Higher is better. Test setup not documented as identical

Claude Opus 4.61,538.785

GPT-6 Astra1,731.395

LMArena Vision, Style ControlChinese. Higher is better. Test setup not documented as identical

Claude Opus 4.61,348.115

GPT-6 Astra1,357.126

Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Our tests

SVG short test

One SVG prompt and fixed output settings. Captures are shown only with 0 reported reasoning tokens or documented lack of reasoning controls. Identical test conditions do not make the models' internal compute identical.

Shared test round: 43b8c5c46830

Claude Opus 4.6

GPT-6 Astra

Unavailable in this round

Earlier tests

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Opus 4.6

Reasoning (requested): high

Current attempt

Run date: Oct 1, 2026
API provider: openrouter
Requested API model: anthropic/claude-opus-4.6
API model reported in response: anthropic/claude-opus-4.6
Reasoning setting: high
Pinned endpoint: Anthropic | anthropic/claude-4.6-opus-20260205
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating
Response time: 85.1 s

Visually reviewed. This individual test does not establish overall model quality.

GPT-6 Astra

Reasoning (requested): high

Current attempt

Run date: Sep 7, 2026
API provider: openrouter
Requested API model: openai/gpt-6-astra
API model reported in response: openai/gpt-6-astra
Reasoning setting: high
Pinned endpoint: OpenAI | openai/gpt-6-astra-20260903
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating
Response time: 141.7 s

Visually reviewed. This individual test does not establish overall model quality.

Prompt and test conditions

Generate an SVG of a pelican riding a bicycle

Token limit including reasoning: 8,192 tokens

Task origin (Simon Willison)

How to read this comparison

Winning one benchmark is not an overall verdict

Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

More matchups

Compare Claude Opus 4.6 and GPT-6 Astra with other leading models using the same data and benchmark logic.

View the complete LLM comparison

Benchmark scores for Claude Opus 4.6 and GPT-6 Astra
Benchmark and task	Claude Opus 4.6	GPT-6 Astra	Source
AA-Omniscience AccuracyOverall Test details No documented difference in the test setupVersion: AA Omniscience diagnosticMetric: AA-Omniscience AccuracyScoring: Higher is betterClaude Opus 4.6: Snapshot: Claude Opus 4.6 (Max), Reasoning: Max, Attempts: AA-reported aggregate; diagnostic-specific run count is not stated on the leaderboard GPT-6 Astra: Snapshot: GPT-6 Astra (Max), Reasoning: Max, Attempts: AA-reported aggregate; diagnostic-specific run count is not stated on the leaderboardClaude Opus 4.6: Exact AA configuration: Claude Opus 4.6 (Max) (release claude-opus-4-6, row claude-opus-4-6-adaptive, UUID 53c98840-47af-49aa-94e6-469fb17e9a1b, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. Proportion of all questions answered correctly, regardless of whether the model answers or abstains on other questions.GPT-6 Astra: Exact AA configuration: GPT-6 Astra (Max) (release gpt-6-astra, row gpt-6-astra, UUID 2f339a97-9a0d-499a-9cb5-e0db665bfa25, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. Proportion of all questions answered correctly, regardless of whether the model answers or abstains on other questions.	47.0% This is the separately published accuracy diagnostic, not the AA-Omniscience Index. AA identifies higher values as better.	Winner62.6% This is the separately published accuracy diagnostic, not the AA-Omniscience Index. AA identifies higher values as better.	Artificial Analysis Source details Data as of: 10/19/2026
AA-Omniscience Hallucination RateOverall Test details No documented difference in the test setupVersion: AA Omniscience diagnosticMetric: AA-Omniscience Hallucination RateScoring: Lower is betterClaude Opus 4.6: Snapshot: Claude Opus 4.6 (Max), Reasoning: Max, Attempts: AA-reported aggregate; diagnostic-specific run count is not stated on the leaderboard GPT-6 Astra: Snapshot: GPT-6 Astra (Max), Reasoning: Max, Attempts: AA-reported aggregate; diagnostic-specific run count is not stated on the leaderboardClaude Opus 4.6: Exact AA configuration: Claude Opus 4.6 (Max) (release claude-opus-4-6, row claude-opus-4-6-adaptive, UUID 53c98840-47af-49aa-94e6-469fb17e9a1b, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. Proportion of incorrect answers among all non-correct responses: incorrect / (incorrect + partial answers + not attempted).GPT-6 Astra: Exact AA configuration: GPT-6 Astra (Max) (release gpt-6-astra, row gpt-6-astra, UUID 2f339a97-9a0d-499a-9cb5-e0db665bfa25, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. Proportion of incorrect answers among all non-correct responses: incorrect / (incorrect + partial answers + not attempted).	62.8% This is the separately published hallucination-rate diagnostic, not the AA-Omniscience Index. AA identifies lower values as better.	Winner51.3% This is the separately published hallucination-rate diagnostic, not the AA-Omniscience Index. AA identifies lower values as better.	Artificial Analysis Source details Data as of: 10/19/2026
LMArena Code Arena WebDevOverall Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 20,698 published pairwise votes.GPT-6 Astra: Arena rating from 5,746 published pairwise votes.	1,537.258 95% confidence interval: ±5.345The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.244 95% confidence interval: ±10.541The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlOverall Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 26,853 published pairwise votes.GPT-6 Astra: Arena rating from 3,590 published pairwise votes.	Higher measured value1,294.46 95% confidence interval: ±6.329The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,285.988 95% confidence interval: ±10.782The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
MedCodeOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Temperature: 1, Output limit: 30,000 tokens GPT-6 Astra: Reasoning: max, Output limit: 128,000 tokens	48.244 %	Higher measured value48.486 %	Vals AI Source details Data as of: 10/13/2026
MedScribeOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Temperature: 1, Output limit: 30,000 tokens GPT-6 Astra: Reasoning: max, Output limit: 128,000 tokens	86.738 %	Higher measured value87.908 %	Vals AI Source details Data as of: 10/13/2026
MMMU-ProOverall Test details No documented difference in the test setupVersion: AA cohort: 1,730 questionsMetric: pass@1 accuracyScoring: Higher is betterClaude Opus 4.6: Snapshot: Claude Opus 4.6 (Max), Reasoning: Max, Attempts: pass@1, one run per question GPT-6 Astra: Snapshot: GPT-6 Astra (Max), Reasoning: Max, Attempts: pass@1, one run per questionClaude Opus 4.6: Exact AA configuration: Claude Opus 4.6 (Max) (release claude-opus-4-6, row claude-opus-4-6-adaptive, UUID 53c98840-47af-49aa-94e6-469fb17e9a1b, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. The AA run covers 1,730 questions with ten answer options. Answers are extracted by regex and scored pass@1.GPT-6 Astra: Exact AA configuration: GPT-6 Astra (Max) (release gpt-6-astra, row gpt-6-astra, UUID 2f339a97-9a0d-499a-9cb5-e0db665bfa25, reasoning=true, source reasoning-token configuration budget=0, suffix=Max). This configured value is not measured token consumption. The AA run covers 1,730 questions with ten answer options. Answers are extracted by regex and scored pass@1.	75.4% The benchmark page describes 3,460 questions in the full MMMU-Pro dataset; AA's methodology specifies a 1,730-question run.	Winner86.9% The benchmark page describes 3,460 questions in the full MMMU-Pro dataset; AA's methodology specifies a 1,730-question run.	Artificial Analysis Source details Data as of: 10/19/2026
Vibe Code Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens GPT-6 Astra: Reasoning: max, Harness: OpenHands, Output limit: 128,000 tokens	57.573 %	Higher measured value89.594 %	Vals AI Source details Data as of: 10/12/2026
LMArena Code Arena WebDevOverall Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 19,443 published pairwise votes.GPT-6 Astra: Arena rating from 5,746 published pairwise votes.	1,546.362 95% confidence interval: ±5.46The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.244 95% confidence interval: ±10.541The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlOverall Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 22,304 published pairwise votes.GPT-6 Astra: Arena rating from 3,590 published pairwise votes.	Higher measured value1,299.232 95% confidence interval: ±6.456The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,285.988 95% confidence interval: ±10.782The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevImage to webdev Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 8,068 published pairwise votes.GPT-6 Astra: Arena rating from 2,739 published pairwise votes.	1,538.785 95% confidence interval: ±9.009The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,731.395 95% confidence interval: ±13.296The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlChinese Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,685 published pairwise votes.GPT-6 Astra: Arena rating from 230 published pairwise votes.	1,348.115 95% confidence interval: ±17.347The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,357.126 95% confidence interval: ±39.572The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevImage to webdev Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 7,930 published pairwise votes.GPT-6 Astra: Arena rating from 2,739 published pairwise votes.	1,542.687 95% confidence interval: ±8.913The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,731.395 95% confidence interval: ±13.296The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlChinese Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,488 published pairwise votes.GPT-6 Astra: Arena rating from 230 published pairwise votes.	1,351.953 95% confidence interval: ±17.967The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,357.126 95% confidence interval: ±39.572The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 20,698 published pairwise votes.GPT-6 Astra: Arena rating from 5,746 published pairwise votes.	1,537.258 95% confidence interval: ±5.345The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.244 95% confidence interval: ±10.541The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlCreative writing vision Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,731 published pairwise votes.GPT-6 Astra: Arena rating from 367 published pairwise votes.	Higher measured value1,297.75 95% confidence interval: ±15.034The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,289.081 95% confidence interval: ±32.749The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 19,443 published pairwise votes.GPT-6 Astra: Arena rating from 5,746 published pairwise votes.	1,546.362 95% confidence interval: ±5.46The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.244 95% confidence interval: ±10.541The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlCreative writing vision Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,405 published pairwise votes.GPT-6 Astra: Arena rating from 367 published pairwise votes.	Higher measured value1,309.447 95% confidence interval: ±16.801The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,289.081 95% confidence interval: ±32.749The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-html Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 2,623 published pairwise votes.GPT-6 Astra: Arena rating from 1,129 published pairwise votes.	1,546.218 95% confidence interval: ±12.521The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.13 95% confidence interval: ±22.887The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlDiagram Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 7,260 published pairwise votes.GPT-6 Astra: Arena rating from 861 published pairwise votes.	Higher measured value1,331.371 95% confidence interval: ±8.825The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,310.509 95% confidence interval: ±20.739The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-html Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 2,474 published pairwise votes.GPT-6 Astra: Arena rating from 1,129 published pairwise votes.	1,558.715 95% confidence interval: ±13.217The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,780.13 95% confidence interval: ±22.887The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlDiagram Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 5,999 published pairwise votes.GPT-6 Astra: Arena rating from 861 published pairwise votes.	Higher measured value1,324.675 95% confidence interval: ±9.238The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,310.509 95% confidence interval: ±20.739The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-react Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 16,319 published pairwise votes.GPT-6 Astra: Arena rating from 3,422 published pairwise votes.	1,528.416 95% confidence interval: ±5.908The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,804.405 95% confidence interval: ±13.548The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlEnglish Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 11,327 published pairwise votes.GPT-6 Astra: Arena rating from 1,205 published pairwise votes.	Higher measured value1,296.058 95% confidence interval: ±8.463The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,288.398 95% confidence interval: ±17.904The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-react Test details Test setup not documented as identicalNo direct winnerVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 15,177 published pairwise votes.GPT-6 Astra: Arena rating from 3,422 published pairwise votes.	1,538.872 95% confidence interval: ±6.058The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,804.405 95% confidence interval: ±13.548The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlEnglish Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 9,251 published pairwise votes.GPT-6 Astra: Arena rating from 1,205 published pairwise votes.	Higher measured value1,301.128 95% confidence interval: ±8.811The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,288.398 95% confidence interval: ±17.904The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlHomework Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 3,708 published pairwise votes.GPT-6 Astra: Arena rating from 480 published pairwise votes.	1,311.92 95% confidence interval: ±10.944The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,346.15 95% confidence interval: ±26.584The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlHomework Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 2,849 published pairwise votes.GPT-6 Astra: Arena rating from 480 published pairwise votes.	1,324.17 95% confidence interval: ±12.006The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	Higher measured value1,346.15 95% confidence interval: ±26.584The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlOcr Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 19,427 published pairwise votes.GPT-6 Astra: Arena rating from 2,449 published pairwise votes.	Higher measured value1,312.247 95% confidence interval: ±6.33The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,301.633 95% confidence interval: ±12.448The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlOcr Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control GPT-6 Astra: Snapshot: gpt-6-astra-max, Reasoning: max, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 15,929 published pairwise votes.GPT-6 Astra: Arena rating from 2,449 published pairwise votes.	Higher measured value1,313.477 95% confidence interval: ±6.575The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,301.633 95% confidence interval: ±12.448The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
Key to the marks:better valuebetter, but not conclusivetie

Claude Opus 4.6 vs. GPT-6 Astra

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Claude Opus 4.6

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