# Claude Mythos 5 vs GPT-5.4 nano

> Side-by-side benchmark comparison for Claude Mythos 5 and GPT-5.4 nano across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-mythos-5-vs-gpt-5-4-nano
- Last updated: September 4, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Claude Mythos 5 if you want the stronger benchmark profile. GPT-5.4 nano only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Mythos 5 leads overall 85 to 62.19.
- The clearest category separation is in multimodal & grounded, where the averages are 85.1 for Claude Mythos 5 and 23.8 for GPT-5.4 nano.
- The biggest single benchmark swing is OSWorld-Verified in Agentic, with scores of 85% and 39%.
- GPT-5.4 nano is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Mythos 5 also has the larger context window at 1M+.

## Model Snapshot

| Property | Claude Mythos 5 | GPT-5.4 nano |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 400K |
| Overall Score | null | 62.19 |
| Benchmarks Covered | 15 | 18 |
| Pricing (input/output) | $10.00 / $50.00 | $0.20 / $1.25 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 37.3 (Supported · #127/151)

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 88% | 46.3% | Claude Mythos 5 |
| OSWorld-Verified | 85% | 39% | Claude Mythos 5 |
| BrowseComp | 88% | Coming soon | Coming soon |
| CyberGym | 83.8% | Coming soon | Coming soon |
| MCP Atlas | Coming soon | 56.1% | Coming soon |
| Toolathlon | Coming soon | 35.5% | Coming soon |
| τ²-bench results | Coming soon | 92.5% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 41.6% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 37.4 (Supported · #150/183)

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 95.5% | Coming soon | Coming soon |
| SWE-bench Pro | 80.3% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 88.0% | Coming soon | Coming soon |
| Vibe Code Bench | Coming soon | 26.10% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 84.0% | Coming soon |
| SWE-bench (Vals) | Coming soon | 69.8% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Mythos 5 public-lane score: 85.1 (Unranked · 3 rankable rows)
- GPT-5.4 nano public-lane score: 23.8 (#45/48)

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Multimodal | 54.9% | Coming soon | Coming soon |
| CharXiv | 93.5% | Coming soon | Coming soon |
| CharXiv w/o tools | 88.9% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 66.1% | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 69.5% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 72.8 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 48.5 (Supported · #99/181)

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 94.1% | 82.8% | Claude Mythos 5 |
| HLE | 64.5% | 37.7% | Claude Mythos 5 |
| HLE w/o tools | 59% | 24.3% | Claude Mythos 5 |
| GPQA Diamond (Vals) | Coming soon | 77.5% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 77.2% | Coming soon |

### Instruction Following

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 92.9 (#9/120)

### Multilingual

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: Coming soon

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| SWE Multilingual | 92.2% | Coming soon | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- GPT-5.4 nano public-lane score: 43.9 (Unranked · 2 rankable rows)

| Benchmark | Claude Mythos 5 | GPT-5.4 nano | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | 97.6% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 25.860% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 6.250% | Coming soon |

## FAQ

### Which is better overall, Claude Mythos 5 or GPT-5.4 nano?

Claude Mythos 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Mythos 5 and GPT-5.4 nano?

The widest category gap is in multimodal & grounded, where the averages are 85.1 for Claude Mythos 5 and 23.8 for GPT-5.4 nano.

### How many benchmarks does Claude Mythos 5 cover on BenchLM?

Claude Mythos 5 currently has 15 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.4 nano cover on BenchLM?

GPT-5.4 nano currently has 18 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Mythos 5 vs Claude Mythos 5.1](/compare/claude-mythos-5-vs-claude-mythos-5-1)
- [GPT-5.4 nano vs Claude Mythos 5.1](/compare/claude-mythos-5-1-vs-gpt-5-4-nano)
- [Claude Mythos 5 vs Claude Mythos Preview](/compare/claude-mythos-5-vs-claude-mythos-preview)
- [GPT-5.4 nano vs Claude Mythos Preview](/compare/claude-mythos-preview-vs-gpt-5-4-nano)

## Explore More

- [Claude Mythos 5 profile](/models/claude-mythos-5)
- [GPT-5.4 nano profile](/models/gpt-5-4-nano)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)