What is the IQ of Claude Mythos 5.1?

Claude Mythos 5.1 does not yet have an estimated IQ. AI IQ publishes a composite score once a model has source-backed benchmark results in at least two of its seven capability dimensions.

Is Claude Mythos 5.1 open source?

No — Claude Mythos 5.1 is a proprietary model. Its weights are not publicly available, so it is used through hosted APIs and products.

When was Claude Mythos 5.1 released?

Claude Mythos 5.1 was publicly released on September 1, 2026.

Anthropic

Claude Mythos 5.1

Public AI IQ model profile with source-backed benchmark results and derived ranking context.

IQ

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EQ

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Effective Cost

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IQ Rank

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Release and Capabilities

Public release	2026-09-01
Modalities	text

Restricted access for vetted cyberdefenders and life scientists through Anthropic's trusted-access programs

Publisher-reported capabilities

Anthropic says Mythos 5.1 and Fable 5.1 share the same underlying model but use different safeguard levels.
Mythos 5.1 is designed to support advanced cybersecurity and life-sciences work under vetted access.

Limitations and availability caveats

The model is currently limited to selected US organizations, with broader access planned but not yet available.
Access remains restricted; published starting prices do not establish unrestricted API availability or complete verified hosted pricing terms.

Official release and model references

Measured Coverage and Estimates

Mythos 5.1 has 0 of 39 tracked IQ benchmark inputs across 0 of 7 dimensions. Raw benchmark tables contain source-backed results only. Derived IQ combines all six dimensions using the shared scoring methodology, including estimates where direct coverage is incomplete. Configured predecessor references: Mythos 5. A reference is an estimation input, not evidence that this model has the predecessor's measured results.

Benchmark versions, evaluation harnesses, and coverage affect comparisons; a missing result is not a score of zero. See the scoring methodology for estimation and uncertainty limits.

IQ Dimensions

Dimension	IQ	Coverage
Abstract Reasoning	113	0/5
Mathematical Reasoning	n/a	0/5
Academic Reasoning	100	0/6
Programmatic Reasoning	n/a	0/6
Computer Use	n/a	0/5
Reliability	n/a	0/6
Knowledge Work	n/a	0/6

Benchmark Results

Benchmark	Score	Dimension

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Frequently Asked Questions

What is the IQ of Claude Mythos 5.1?: Claude Mythos 5.1 does not yet have an estimated IQ. AI IQ publishes a composite score once a model has source-backed benchmark results in at least two of its seven capability dimensions.
Is Claude Mythos 5.1 open source?: No — Claude Mythos 5.1 is a proprietary model. Its weights are not publicly available, so it is used through hosted APIs and products.
When was Claude Mythos 5.1 released?: Claude Mythos 5.1 was publicly released on September 1, 2026.