# Claude Mythos 5 vs Grok 4.3

> Side-by-side benchmark comparison for Claude Mythos 5 and Grok 4.3 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-mythos-5-vs-grok-4-3
- Last updated: September 4, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for Claude Mythos 5 and Grok 4.3.

## Summary

- Claude Mythos 5 and Grok 4.3 do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | Claude Mythos 5 | Grok 4.3 |
|----------|----------|----------|
| Creator | Anthropic | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 1M |
| Independent public score (not head-to-head) | null | 60.37 |
| Benchmarks Covered | 15 | 7 |
| Pricing (input/output) | $10.00 / $50.00 | $1.25 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: 25 (Supported · #147/151)

| Benchmark | Claude Mythos 5 | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 88% | Coming soon | Coming soon |
| OSWorld-Verified | 85% | Coming soon | Coming soon |
| BrowseComp | 88% | Coming soon | Coming soon |
| CyberGym | 83.8% | Coming soon | Coming soon |
| Gert Labs | Coming soon | 43.86% | Coming soon |
| ResearchClawBench | Coming soon | 12.4% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 41.9% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: 33.7 (Supported · #159/183)

| Benchmark | Claude Mythos 5 | Grok 4.3 | 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 |
| LiveCodeBench (Vals) | Coming soon | 84.5% | Coming soon |
| SWE-bench (Vals) | Coming soon | 71.4% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: 85.1 (Unranked · 3 rankable rows)
- Grok 4.3 public-lane score: 65.6 (#25/48)

| Benchmark | Claude Mythos 5 | Grok 4.3 | 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 |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: 67.2 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: 57.4 (Supported · #48/181)

| Benchmark | Claude Mythos 5 | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 94.1% | Coming soon | Coming soon |
| HLE | 64.5% | Coming soon | Coming soon |
| HLE w/o tools | 59% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 91.4% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 85.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: 94.4 (#2/120)

### Multilingual

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: Coming soon

| Benchmark | Claude Mythos 5 | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| SWE Multilingual | 92.2% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Mythos 5 public-lane score: Coming soon
- Grok 4.3 public-lane score: Coming soon

| Benchmark | Claude Mythos 5 | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | 97.6% | Coming soon | Coming soon |

## FAQ

### Can I compare Claude Mythos 5 and Grok 4.3 on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [Claude Mythos 5 vs Claude Mythos 5.1](/compare/claude-mythos-5-vs-claude-mythos-5-1)
- [Grok 4.3 vs Claude Mythos 5.1](/compare/claude-mythos-5-1-vs-grok-4-3)
- [Claude Mythos 5 vs Claude Mythos Preview](/compare/claude-mythos-5-vs-claude-mythos-preview)
- [Grok 4.3 vs Claude Mythos Preview](/compare/claude-mythos-preview-vs-grok-4-3)

## Explore More

- [Claude Mythos 5 profile](/models/claude-mythos-5)
- [Grok 4.3 profile](/models/grok-4-3)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)