Model comparison
Claude Mythos 5 vs Grok 4.1 Fast (Reasoning)
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Mythos 5 #1 (Supported); Grok 4.1 Fast (Reasoning) #48 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Mythos 5 and Grok 4.1 Fast (Reasoning) share 0 comparable benchmark results. 0 of 8 categories are comparable. 15 results are unique to Claude Mythos 5; 13 to Grok 4.1 Fast (Reasoning).
Updated July 23, 2026- Shared results
- 0
- Claude Mythos 5 only
- 15
- Grok 4.1 Fast (Reasoning) only
- 13
- Comparable categories
- 0 / 8
Benchmark data for Claude Mythos 5 and Grok 4.1 Fast (Reasoning) is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Grok 4.1 Fast (Reasoning) has the larger context window at 2M, compared with 1M+ for Claude Mythos 5.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Mythos 5 | Grok 4.1 Fast (Reasoning) | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Mythos 5$10 input / $50 output | Grok 4.1 Fast (Reasoning)Not available | A complete price comparison is not available. |
| Generation speedtokens per second | Claude Mythos 5Not available | Grok 4.1 Fast (Reasoning)Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Mythos 5Not available | Grok 4.1 Fast (Reasoning)Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Mythos 51M+ | Grok 4.1 Fast (Reasoning)2M | Grok 4.1 Fast (Reasoning) lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding5 benchmarks
Reasoning2 benchmarks
Knowledge9 benchmarks
| Benchmark | Claude Mythos 5 | Grok 4.1 Fast (Reasoning) | Result |
|---|---|---|---|
| GPQASource | 94.1% | — | Not comparable |
| HLESource | 64.5% | — | Not comparable |
| HLE w/o toolsSource | 59% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 30.6% | Not comparable |
| AA-GPQA DiamondSource | — | 85.3% | Not comparable |
| AA-HLESource | — | 17.6% | Not comparable |
| AA-Omniscience IndexSource | — | -28.7% | Not comparable |
| AA-Omniscience AccuracySource | — | 25.3% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 72.4% | Not comparable |
Math1 benchmarks
| Benchmark | Claude Mythos 5 | Grok 4.1 Fast (Reasoning) | Result |
|---|---|---|---|
| USAMO 2026Source | 97.6% | — | Not comparable |
Multilingual1 benchmarks
| Benchmark | Claude Mythos 5 | Grok 4.1 Fast (Reasoning) | Result |
|---|---|---|---|
| SWE MultilingualSource | 92.2% | — | Not comparable |
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Mythos 5 | Grok 4.1 Fast (Reasoning) | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 52.7% | Not comparable |
Frequently Asked Questions (3)
Can I compare Claude Mythos 5 and Grok 4.1 Fast (Reasoning) on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Claude Mythos 5 and Grok 4.1 Fast (Reasoning) today?
Claude Mythos 5: $10.00 input / $50.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
Related Comparisons
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.