Models · Anthropic · Out sinceReleased 7 Apr 2026

Claude Mythos Preview

Only from the makerNot on OpenRouterEarly accessPreviewClosed (can't be downloaded)Proprietary

Claude Mythos Preview is made by Anthropic. We don't have enough test results yet to rank it.

Limited-access preview model; METR measured an early checkpoint. Not on OpenRouter.

Writing & creativity: —
Research & analysis: —
Coding: —
Price: Price unknown— / —
Price per 1M (blended)Blended / 1M: —
MemoryContext: —
Longest answerMax output: —
Test resultsResults: 1 (1 independent1 indep.)
Out sinceReleased: 7 Apr 2026
Made byVendor: Anthropic
UnderstandsInputs: —

Scores are out of 100 for each area, compared with every model we track; “#” is its rank. Context is how much text it can read at once (1M is roughly 700,000 words). Blended price mixes the cost of what you send and what it writes back.

Thinking levels

Reasoning settings

You can't choose how long this one thinks.

No adjustable reasoning setting listed.

Links

Anthropic's model listAnthropic docs ↗

Every test result

Every result

All the numbers,with where they came from.

Every result we've found for this model, with who measured it and a link to where we read it.

All raw rows (vendor and independent kept separate), with setting label, source, date, harness and notes.

All results for this model
						NotesNotes
METR 50% time horizon	17.4 h	Default	Independent testIndependentMETR ↗	8 May 2026	METR react agent (Inspect)	50% time horizon, METR-Horizon-v1.1; 95% CI 509-3304 min; 80% horizon 185.9 min; release 2026-04-07; raw data https://metr.org/assets/benchmark_results_1_1.yaml; early checkpoint