Head-to-head comparison

GPT-5.6 Terra vs. Gemini 4 Argon

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

shared result series: 161
distinct benchmark metrics: 21
latest retrieval: 2026-10-16

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 GPT-5.6 Terra and Gemini 4 Argon
Attribute	GPT-5.6 Terra	Gemini 4 Argon
Provider	OpenAI	Google DeepMind
Released	Jul 9, 2026	Oct 13, 2026
Availability	Active	Active
Model type	Proprietary	Proprietary
Parameters	Not published	Not published
Architecture	Not published	Not published
Context window	1,050,000 tokens	1,048,576 tokens shared across input, thinking, and output
Knowledge cutoff	February 16, 2026	Not published
Technical sources	Model, Context, Knowledge cutoff	Model

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 GPT-5.6 Terra and Gemini 4 Argon
Price type	GPT-5.6 Terra	Gemini 4 Argon
API input	$2 ≤272K / $4 >272K	$2
API output	$12 ≤272K / $18 >272K	$10
Cache read	$0.2 ≤272K / $0.4 >272K	$0.1
Cache write (5 min.)	$2.5 ≤272K / $5 >272K	Not listed
Cache write (1 hr.)	Not listed	Not listed
Price verified	09/22/2026 Source	10/25/2026 Source
Gemini 4 Argon, Standard pricing through November 30, 2026 Per 1 million tokens: $2.00 input, $10.00 output including thinking, and $0.10 cached input. Source
Gemini 4 Argon, Standard pricing from December 1, 2026 Per 1 million tokens: $4.00 input, $20.00 output including thinking, and $0.20 cached input. Source
Gemini 4 Argon, Caching Implicit caching only; explicit caching is not supported. Source

GPT-5.6 TerraGemini 4 Argon

API inputUSD per 1M tokens, base tier

GPT-5.6 Terra$2

Gemini 4 Argon$2

API outputUSD per 1M tokens, base tier

GPT-5.6 Terra$12

Gemini 4 Argon$10

Cache readUSD per 1M tokens, base tier

GPT-5.6 Terra$0.2

Gemini 4 Argon$0.1

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.

No provider tariff for Gemini 4 Argon is available in the stored OpenRouter snapshot. The official direct price is still shown.

Provider pricing for GPT-5.6 Terra and Gemini 4 Argon
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
GPT-5.6 Terra	OpenAI	Direct from developerUp to 272,000 context tokens	$2	$12	Source09/22/2026
	OpenAI	Direct from developerAbove 272,000 context tokens	$4	$18	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us-east-1	$2.2	$13.2	Source10/26/2026
	Azure	Via OpenRouterazure	$2	$12	Source10/26/2026
	Azure	Via OpenRouterazure/eu	$2.2	$13.2	Source10/26/2026
	Azure	Via OpenRouterazure/us	$2.2	$13.2	Source10/26/2026
	OpenAI	Via OpenRouteropenai	$2	$12	Source10/26/2026
	OpenAI	Via OpenRouteropenai/fast	$4	$24	Source10/26/2026
	OpenAI	Via OpenRouteropenai/flex	Lowest listed price: $1	Lowest listed price: $6	Source10/26/2026
Gemini 4 Argon	Google DeepMind	Direct from developerStandard API	Lowest listed price: $2	Lowest listed price: $10	Source10/25/2026

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

GPT-5.6 Terra

Overall index

52.1

Gemini 4 Argon

Overall index

92.6

Gemini 4 Argon leads in 11 of 11 shared areas.

Area	GPT-5.6 Terra	Gemini 4 Argon
Coding	61.3	92.4
Reasoning	56.6	91.6
Mathematics	54.8	89.3
Knowledge	29.3	93.6
General	63.6	90.2
Finance	60.4	94.6
Legal	41.4	94.9
Health	40.3	92.8
Cybersecurity	56.7	92.8
Productivity	49.1	90.6
Education	56.5	93.6

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

GPT-5.6 TerraGemini 4 Argon

Code MigrationOverall. Higher is better. Test setup not documented as identical

GPT-5.6 Terra47.804 %

Gemini 4 Argon68.173 %

CyberBench v1.1Overall. Higher is better. Test setup not documented as identical

GPT-5.6 Terra72.084 %

Gemini 4 Argon77.857 %

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

GPT-5.6 Terra66.205 %

Gemini 4 Argon75.244 %

Finance Agent (v2)Overall. Higher is better. Test setup not documented as identical

GPT-5.6 Terra54.436 %

Gemini 4 Argon65.401 %

Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. Test setup not documented as identical

GPT-5.6 Terra0.833 %

Gemini 4 Argon19.583 %

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

GPT-5.6 Terra87.611 %

Gemini 4 Argon100 %

Legal Research BenchOverall · All-pass. Higher is better. Test setup not documented as identical

GPT-5.6 Terra41.346 %

Gemini 4 Argon54.808 %

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

GPT-5.6 Terra85.105 %

Gemini 4 Argon88.299 %

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

GPT-5.6 Terra43.414 %

Gemini 4 Argon58.801 %

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

GPT-5.6 Terra82.869 %

Gemini 4 Argon87.427 %

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

GPT-5.6 Terra0.5 %

Gemini 4 Argon2.5 %

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

GPT-5.6 Terra74 %

Gemini 4 Argon99 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for GPT-5.6 Terra and Gemini 4 Argon
Benchmark and task	GPT-5.6 Terra	Gemini 4 Argon	Source
Code MigrationOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	47.804 %	Higher measured value68.173 %	Vals AI Source details Data as of: 10/12/2026
CyberBench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	72.084 %	Higher measured value77.857 %	Vals AI Source details Data as of: 10/12/2026
EMBOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	66.205 %	Higher measured value75.244 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Overall Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	54.436 %	Higher measured value65.401 %	Vals AI Source details Data as of: 10/12/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	0.833 %	Higher measured value19.583 %	Vals AI Source details Data as of: 10/12/2026
IOIOverall Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	87.611 %	Higher measured value100 %	Vals AI Source details Data as of: 10/14/2026
Legal Research BenchOverall · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	41.346 %	Higher measured value54.808 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	85.105 %	Higher measured value88.299 %	Vals AI Source details Data as of: 10/13/2026
MedCodeOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: xhigh, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	43.414 %	Higher measured value58.801 %	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 betterGPT-5.6 Terra: Reasoning: xhigh, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	82.869 %	Higher measured value87.427 %	Vals AI Source details Data as of: 10/13/2026
ProgramBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully resolved rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	0.5 %	Higher measured value2.5 %	Vals AI Source details Data as of: 10/12/2026
ProofBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	74 %	Higher measured value99 %	Vals AI Source details Data as of: 10/12/2026
Public Benefits Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	62.382 %	Higher measured value69.756 %	Vals AI Source details Data as of: 10/12/2026
SAGEOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	47.003 %	Higher measured value53.645 %	Vals AI Source details Data as of: 10/08/2026
SRE BenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully solved rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	9.542 %	Higher measured value44.275 %	Vals AI Source details Data as of: 10/14/2026
Tax Agent BenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	30.035 %	Higher measured value44.56 %	Vals AI Source details Data as of: 10/12/2026
Terminal-Bench 4.0Overall Test details Test setup not documented as identicalNo direct winnerVersion: 4.0Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	22.727 %	Higher measured value57.576 %	Vals AI Source details Data as of: 10/13/2026
Terminal-Bench ScienceOverall Test details Test setup not documented as identicalNo direct winnerVersion: 0.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: Mini-SWE-agent, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: Mini-SWE-agent, Temperature: 1, Output limit: 262,144 tokens	10 %	Higher measured value44.286 %	Vals AI Source details Data as of: 10/14/2026
Vals IndexOverall Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: weighted index scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	53.085 %	Higher measured value68.896 %	Vals AI Source details Data as of: 10/13/2026
Vibe Code Bench 1-100Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.0Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: OpenHands, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: OpenHands, Temperature: 1, Output limit: 262,144 tokens	14.822 %	Higher measured value21.2 %	Vals AI Source details Data as of: 10/14/2026
Vibe Code Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: OpenHands, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: OpenHands, Temperature: 1, Output limit: 262,144 tokens	74.594 %	Higher measured value91.906 %	Vals AI Source details Data as of: 10/12/2026
Code MigrationCLI Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	40.405 %	Higher measured value67.564 %	Vals AI Source details Data as of: 10/12/2026
CyberBench v1.1Patch Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	Higher measured value87.5 %	85.714 %	Vals AI Source details Data as of: 10/12/2026
EMBComps Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	62.157 %	Higher measured value82.979 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Adjustments Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	49.711 %	Higher measured value60.527 %	Vals AI Source details Data as of: 10/12/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	77.536 %	Higher measured value94.203 %	Vals AI Source details Data as of: 10/12/2026
IOIIOI 2024 Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	85 %	Higher measured value100 %	Vals AI Source details Data as of: 10/14/2026
Legal Research BenchAdministrative / Regulatory · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	57.576 %	Higher measured value68.182 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchConclusion Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	90.327 %	Higher measured value90.847 %	Vals AI Source details Data as of: 10/13/2026
ProgramBenchAlmost Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: almost-resolved rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	15 %	Higher measured value41 %	Vals AI Source details Data as of: 10/12/2026
SAGEAutomata Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	38.889 %	Higher measured value45.635 %	Vals AI Source details Data as of: 10/08/2026
SRE BenchCapability Score Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: capability scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	26.845 %	Higher measured value57.824 %	Vals AI Source details Data as of: 10/14/2026
Tax Agent BenchControversy & Precedence Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	16.667 %	Higher measured value20 %	Vals AI Source details Data as of: 10/12/2026
Terminal-Bench 4.0Hardware Test details Test setup not documented as identicalNo direct winnerVersion: 4.0Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	0 %	Higher measured value46.667 %	Vals AI Source details Data as of: 10/13/2026
Terminal-Bench ScienceEarth Sciences Test details Test setup not documented as identicalNo direct winnerVersion: 0.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: Mini-SWE-agent, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: Mini-SWE-agent, Temperature: 1, Output limit: 262,144 tokens	0 %	Higher measured value62.5 %	Vals AI Source details Data as of: 10/14/2026
Vals IndexCode Migration Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	48.248 %	Higher measured value69.503 %	Vals AI Source details Data as of: 10/13/2026
Code MigrationCOBOL Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	No direct winner70 %	No direct winner70 %	Vals AI Source details Data as of: 10/12/2026
CyberBench v1.1PoC Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	56.667 %	Higher measured value70 %	Vals AI Source details Data as of: 10/12/2026
EMBDataroom Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	82.161 %	Higher measured value85.109 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)All-Pass Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	42.756 %	Higher measured value55.789 %	Vals AI Source details Data as of: 10/12/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	0 %	Higher measured value20 %	Vals AI Source details Data as of: 10/12/2026
IOIIOI 2025 Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	77.833 %	Higher measured value100 %	Vals AI Source details Data as of: 10/14/2026
Legal Research BenchAdministrative / Regulatory · Weighted partial credit Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: weighted partial-credit scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	88.759 %	Higher measured value92.945 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchInterpretation Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	83.178 %	Higher measured value84.097 %	Vals AI Source details Data as of: 10/13/2026
ProgramBenchFully Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully resolved rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	0.5 %	Higher measured value2.5 %	Vals AI Source details Data as of: 10/12/2026
SAGECalculus Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	59.259 %	Higher measured value84.877 %	Vals AI Source details Data as of: 10/08/2026
SRE BenchFully Solved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully solved rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	9.542 %	Higher measured value44.275 %	Vals AI Source details Data as of: 10/14/2026
Tax Agent BenchControversy & Precedence Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	Higher measured value64.833 %	63.603 %	Vals AI Source details Data as of: 10/12/2026
Terminal-Bench 4.0Media Test details Test setup not documented as identicalNo direct winnerVersion: 4.0Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	16.667 %	Higher measured value83.333 %	Vals AI Source details Data as of: 10/13/2026
Terminal-Bench ScienceEngineering Sciences Test details Test setup not documented as identicalNo direct winnerVersion: 0.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: Mini-SWE-agent, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: Mini-SWE-agent, Temperature: 1, Output limit: 262,144 tokens	0 %	Higher measured value11.111 %	Vals AI Source details Data as of: 10/14/2026
Vals IndexEMB Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	66.205 %	Higher measured value75.244 %	Vals AI Source details Data as of: 10/13/2026
Code MigrationCode Quality Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: mean reviewer code-quality ratingScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	Higher measured value3.948 / 5	3.574 / 5	Vals AI Source details Data as of: 10/12/2026
EMBDCF Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	53.395 %	Higher measured value65.719 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Comparables Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	47.032 %	Higher measured value50.956 %	Vals AI Source details Data as of: 10/12/2026
Harvey's Legal Agent BenchmarkArbitration International Dispute Resolution · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	72.76 %	Higher measured value94.265 %	Vals AI Source details Data as of: 10/12/2026
IOIIOI 2026 Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	No direct winner100 %	No direct winner100 %	Vals AI Source details Data as of: 10/14/2026
Legal Research BenchBusiness & Commercial · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	37.209 %	Higher measured value46.512 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchIssue Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	89.392 %	Higher measured value92.941 %	Vals AI Source details Data as of: 10/13/2026
ProgramBenchRaw Pass Rate Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: raw test pass rateScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	72.345 %	Higher measured value83.715 %	Vals AI Source details Data as of: 10/12/2026
SAGELinear Algebra Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 30,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	64.025 %	Higher measured value74.031 %	Vals AI Source details Data as of: 10/08/2026
Tax Agent BenchCurrent & Temporal Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	33.222 %	Higher measured value66.667 %	Vals AI Source details Data as of: 10/12/2026
Terminal-Bench 4.0ML Test details Test setup not documented as identicalNo direct winnerVersion: 4.0Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	15.152 %	Higher measured value69.697 %	Vals AI Source details Data as of: 10/13/2026
Terminal-Bench ScienceLife Sciences Test details Test setup not documented as identicalNo direct winnerVersion: 0.1Metric: accuracyScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Harness: Mini-SWE-agent, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Harness: Mini-SWE-agent, Temperature: 1, Output limit: 262,144 tokens	15.789 %	Higher measured value42.105 %	Vals AI Source details Data as of: 10/14/2026
Vals IndexFinance Agent v2 Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: benchmark scoreScoring: Higher is betterGPT-5.6 Terra: Reasoning: max, Output limit: 128,000 tokens Gemini 4 Argon: Reasoning: high, Temperature: 1, Output limit: 262,144 tokens	54.436 %	Higher measured value65.401 %	Vals AI Source details Data as of: 10/13/2026
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

GPT-5.6 Terra

Unavailable in this round

Gemini 4 Argon

Unavailable in this round

Earlier tests

Pelican on a bicycle

A community classic for free-form SVG drawing.

GPT-5.6 Terra

Reasoning (requested): high

Current attempt

Run date: Sep 7, 2026
API provider: openrouter
Requested API model: openai/gpt-5.6-terra
API model reported in response: openai/gpt-5.6-terra
Reasoning setting: high
Pinned endpoint: OpenAI | openai/gpt-5.6-terra-20260709
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: 64.6 s

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

Gemini 4 Argon

Not tested yet

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.

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Compare GPT-5.6 Terra and Gemini 4 Argon with other leading models using the same data and benchmark logic.

View the complete LLM comparison

GPT-5.6 Terra vs. Gemini 4 Argon

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General specifications

API pricing compared

Benchmark index compared

Shared benchmarks

Capability profile from matched benchmarks

Our tests

SVG short test

GPT-5.6 Terra

Gemini 4 Argon

Pelican on a bicycle

Winning one benchmark is not an overall verdict

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