# Claude Mythos 5.1 Benchmark Scores & Performance

> Claude Mythos 5.1 by Anthropic has 1 source-displayable benchmark rows but no public overall score. It remains unranked.

Canonical page: https://benchlm.ai/models/claude-mythos-5-1

Last updated: October 16, 2026

## Model Details

| Property | Value |
|----------|-------|
| Creator | Anthropic |
| Source Type | Proprietary |
| Reasoning Type | Reasoning |
| Context Window | 1M |
| Official model card | [Claude Fable 5.1 and Claude Mythos 5.1 system card](https://www-cdn.anthropic.com/0339e6a7c5c7b87f5c07798616dc32c215d14235/Claude%20Fable%205.1%20&%20Claude%20Mythos%205.1%20System%20Card.pdf) |
| Overall Score | Not computed (unranked) |
| Overall Rank | Unranked |

## Family & Coverage

- Family: Claude Mythos
- Variant: restricted
- Benchmarks covered: 1 of 639
- Sibling models: [Claude Mythos 5](/models/claude-mythos-5), [Claude Mythos Preview](/models/claude-mythos-preview)
- Related earlier model: [Claude Mythos 5](/models/claude-mythos-5)
- Coverage note: Published evidence is shown below; no public overall score is assigned.

## Agentic Benchmarks

| Benchmark | Score | Source |
|-----------|-------|--------|
| [Terminal-Bench 4.0](/benchmarks/terminal-bench-4) | 60.90% | [Anthropic: Claude Fable 5.1 and Claude Mythos 5.1 system card](https://www-cdn.anthropic.com/0339e6a7c5c7b87f5c07798616dc32c215d14235/Claude%20Fable%205.1%20&%20Claude%20Mythos%205.1%20System%20Card.pdf) |

## Other Anthropic Models

- [Claude Opus 5.5](/models/claude-opus-5-5) - Score: 86.54
- [Claude Fable 5.1](/models/claude-fable-5-1) - Score: 83.17
- [Claude Sonnet 5.5](/models/claude-sonnet-5-5) - Score: 82.17
- [Claude Fable 5](/models/claude-fable) - Score: 81.25
- [Claude Opus 5](/models/claude-opus-5) - Score: 79.61
- [Claude Haiku 5.5](/models/claude-haiku-5-5) - Score: 70.03
- [Claude Opus 4.8](/models/claude-opus-4-8) - Score: 69.99
- [Claude Opus 4.7 (Adaptive)](/models/claude-opus-4-7-adaptive) - Score: 68.95
- [Claude Opus 4.7](/models/claude-opus-4-7) - Score: 66.72
- [Claude Sonnet 5](/models/claude-sonnet-5) - Score: 64.83
- [Claude Opus 4.6](/models/claude-opus-4-6) - Score: 62.38
- [Claude Sonnet 4.6](/models/claude-sonnet-4-6) - Score: 55.88
- [Claude Opus 4.5 Thinking](/models/claude-opus-4-5-thinking) - Score: 54.09
- [Claude Opus 4.5](/models/claude-opus-4-5) - Score: 54.04
- [Claude Sonnet 4.5](/models/claude-sonnet-4-5) - Score: 47.95
- [Claude Haiku 4.5](/models/claude-haiku-4-5) - Score: 41.15
- [Claude 4.1 Opus](/models/claude-4-1-opus) - Score: 40.05
- [Claude 4.1 Opus Thinking](/models/claude-4-1-opus-thinking) - Score: 39.36
- [Claude 4 Sonnet](/models/claude-4-sonnet) - Score: 38.08
- [Claude 3 Opus](/models/claude-3-opus) - Score: 28.49
- [Claude 3.5 Sonnet](/models/claude-3-5-sonnet) - Score: 27.72
- [Claude 3 Haiku](/models/claude-3-haiku) - Score: 14.19
- [Claude Mythos 5](/models/claude-mythos-5) - Score: not computed
- [Claude 4 Opus Thinking](/models/claude-4-opus-thinking) - Score: not computed
- [Claude Opus 4.6 (Adaptive)](/models/claude-opus-4-6-thinking) - Score: not computed
- [Claude 4 Opus](/models/claude-4-opus) - Score: not computed
- [Claude 3.7 Sonnet Thinking](/models/claude-3-7-sonnet-thinking) - Score: not computed
- [Claude 3.7 Sonnet](/models/claude-3-7-sonnet) - Score: not computed
- [Claude 3.5 Haiku](/models/claude-3-5-haiku) - Score: not computed
- [Claude Sonnet 4.5 Thinking](/models/claude-sonnet-4-5-thinking) - Score: not computed
- [Claude Mythos Preview](/models/claude-mythos-preview) - Score: not computed
- [Claude Haiku 4.5 Thinking](/models/claude-haiku-4-5-thinking) - Score: not computed