Head-to-head comparison
Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.
Specifications
Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.
| Attribute | Claude Mythos 5.1 | Claude Haiku 4.5 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Released | Sep 1, 2026 | Oct 2025 |
| Availability | Limited access | Active |
| Model type | Proprietary | Proprietary |
| Parameters | Not published | Not published |
| Architecture | Not published | Not published |
| Context window | 1,000,000 tokens | 200,000 tokens |
| Knowledge cutoff | June 2026 | February 2025 |
| Technical sources | Model | Model |
Pricing
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.
| Price type | Claude Mythos 5.1 | Claude Haiku 4.5 |
|---|---|---|
| API input | $10 | $1 |
| API output | $50 | $5 |
| Cache read | $0.25 | $0.1 |
| Cache write (5 min.) | $12.5 | $1.25 |
| Cache write (1 hr.) | $20 | $2 |
| Price verified | 09/02/2026 Source | 07/30/2026 Source |
Key to the marks:better valuebetter, but not conclusivetie
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 Claude Mythos 5.1 is available in the stored OpenRouter snapshot. The official direct price is still shown.
| Model | Provider | Purchase route and tariff | Input per 1M tokens | Output per 1M tokens | Source |
|---|---|---|---|---|---|
| Claude Mythos 5.1 | Anthropic | Direct from developerStandard API | Lowest listed price: $10 | Lowest listed price: $50 | Source09/02/2026 |
| Claude Haiku 4.5 | Anthropic | Direct from developerStandard API | Lowest listed price: $1 | Lowest listed price: $5 | Source07/30/2026 |
| Amazon Bedrock | Via OpenRouteramazon-bedrock/eu-west-1 | $1.1 | $5.5 | Source09/12/2026 | |
| Amazon Bedrock | Via OpenRouteramazon-bedrock/global | Lowest listed price: $1 | Lowest listed price: $5 | Source09/12/2026 | |
| Amazon Bedrock | Via OpenRouteramazon-bedrock/us | $1.1 | $5.5 | Source09/12/2026 | |
| Anthropic | Via OpenRouteranthropic | Lowest listed price: $1 | Lowest listed price: $5 | Source09/12/2026 | |
| Azure | Via OpenRouterazure/global | Lowest listed price: $1 | Lowest listed price: $5 | Source09/12/2026 | |
| Via OpenRoutergoogle-vertex/europe | $1.1 | $5.5 | Source09/12/2026 | ||
| Via OpenRoutergoogle-vertex/global | Lowest listed price: $1 | Lowest listed price: $5 | Source09/12/2026 | ||
| Via OpenRoutergoogle-vertex/us-east5 | $1.1 | $5.5 | Source09/12/2026 |
Performance
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.
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.
No published benchmark for Claude Mythos 5.1 and Claude Haiku 4.5 currently matches in version, task, metric, and comparison cohort. We therefore show no estimated or blended values.
Our model tests
Compare how the models respond to the same prompt. Each test shows the first attempt, with no subsequent fixes to the generated code. These results do not contribute to an overall score.
A community classic for free-form SVG drawing.
Claude Mythos 5.1
No available test access
Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.
Claude Haiku 4.5
Not tested yet
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
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 Mythos 5.1 and Claude Haiku 4.5 with other leading models using the same data and benchmark logic.