Claude Mythos Preview vs GPT-4.1

Pick Claude Mythos Preview if you want the stronger benchmark profile. GPT-4.1 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Claude Mythos Preview is clearly ahead on the aggregate, 84 to 64. 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 54.6. The single biggest benchmark swing on the page is SWE-bench Verified, 93.9% to 54.6%.

Claude Mythos Preview is also the more expensive model on tokens at $25.00 input / $125.00 output per 1M tokens, versus $2.00 input / $8.00 output per 1M tokens for GPT-4.1. That is roughly 15.6x on output cost alone. Claude Mythos Preview is the reasoning model in the pair, while GPT-4.1 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.