# Claude Mythos 5.1 vs Pareto 26.9

> Side-by-side benchmark comparison for Claude Mythos 5.1 and Pareto 26.9 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-mythos-5-1-vs-pareto-26-9
- Last updated: September 18, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Mythos 5.1 and Pareto 26.9 share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Claude Mythos 5.1 has the lower published output-token price.
- Claude Mythos 5.1 has the larger published context window at 1M.

## Model Snapshot

| Property | Claude Mythos 5.1 | Pareto 26.9 |
|----------|----------|----------|
| Creator | Anthropic | Unbiased |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | N/A |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 1 | 4 |
| Pricing (input/output) | Pricing unavailable / Pricing unavailable | $2.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Mythos 5.1 public-lane score: Coming soon
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | Claude Mythos 5.1 | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 60.90% | 51.00% | Claude Mythos 5.1 |

### Coding

- Winner: Insufficient shared evidence
- Claude Mythos 5.1 public-lane score: Coming soon
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | Claude Mythos 5.1 | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| DeepSWE | Coming soon | 74.0% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Mythos 5.1 public-lane score: Coming soon
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | Claude Mythos 5.1 | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | Coming soon | 78% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Mythos 5.1 public-lane score: Coming soon
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | Claude Mythos 5.1 | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| HLE w/o tools | Coming soon | 49% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Mythos 5.1 and Pareto 26.9?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Mythos 5.1 vs Claude Mythos 5](/compare/claude-mythos-5-vs-claude-mythos-5-1)
- [Pareto 26.9 vs Claude Mythos 5](/compare/claude-mythos-5-vs-pareto-26-9)
- [Claude Mythos 5.1 vs Claude Mythos Preview](/compare/claude-mythos-5-1-vs-claude-mythos-preview)
- [Pareto 26.9 vs Claude Mythos Preview](/compare/claude-mythos-preview-vs-pareto-26-9)

## Explore More

- [Claude Mythos 5.1 profile](/models/claude-mythos-5-1)
- [Pareto 26.9 profile](/models/pareto-26-9)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)