Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Mythos Preview
99
Grok Code Fast 1
42
Verified leaderboard positions: Claude Mythos Preview #1 · Grok Code Fast 1 unranked
Pick Claude Mythos Preview if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
Coding
+13.0 difference
Claude Mythos Preview
Grok Code Fast 1
$25 / $125
$null / $null
N/A
172 t/s
N/A
2.81s
1M
256K
Pick Claude Mythos Preview if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
Claude Mythos Preview is clearly ahead on the provisional aggregate, 99 to 42. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Mythos Preview's sharpest advantage is in coding, where it averages 83.8 against 70.8. The single biggest benchmark swing on the page is SWE-bench Verified, 93.9% to 70.8%.
Claude Mythos Preview is the reasoning model in the pair, while Grok Code Fast 1 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Mythos Preview gives you the larger context window at 1M, compared with 256K for Grok Code Fast 1.
Claude Mythos Preview is ahead on BenchLM's provisional leaderboard, 99 to 42. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 93.9% and 70.8%.
Claude Mythos Preview has the edge for coding in this comparison, averaging 83.8 versus 70.8. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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