> Claude Mythos 5 is a closed AI model from Anthropic, released 9 Jun 2026.

[Models](https://themodelindex.org/models/) /[Anthropic](https://themodelindex.org/labs/anthropic/)

# Claude Mythos 5

Anthropic

Released 9 Jun 2026

Closed

Flagship

Date verified

[Compare](https://themodelindex.org/compare/claude-mythos-5-vs-glm-5-2/) [Announcement](https://www.anthropic.com/news/claude-fable-5-mythos-5)

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Index score

Not yet evaluated independently

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Core tests taken

no independent results yet

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Versus the frontier at release

Replaced by [Claude Mythos 5.1](https://themodelindex.org/models/claude-mythos-5-1/)

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Price per million tokens

no public API price found

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Context window

tokens it reads at once

## Where it sits · on the frontier

_Chart: Model Index score of every scored model since late 2022, with the best closed and best open model over time_

Not plotted: no index score yet.

## Test results · by area · tick = best by any model

Reasoning & knowledge

no evidence yet

GPQA Diamond

no result

Humanity's Last Exam

no result

Maths

no evidence yet

FrontierMath T1-3

no result

Coding

no evidence yet

SWE-bench Verified

no result

Terminal-Bench

no result

Agents

no evidence yet

APEX-Agents

no result

Novel problems

no evidence yet

ARC-AGI-2

no result

Long tasks

no evidence yet

METR time horizon

no result

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

## What others say · rank on each leaderboard

Not on any of the rankings we follow yet.

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

## Best at · top three among current models

Replaced by Claude Mythos 5.1; it no longer leads any category among current models.

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

## Where to use it · prices checked 1 Oct 2026

#### From the lab

Claude

app · subscription

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Claude API

API

↗

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

## Facts and sources

Released

9 Jun 2026

Announcement

[anthropic.com ↗](https://www.anthropic.com/news/claude-fable-5-mythos-5)

Release entry

Claude Fable 5 + Mythos 5 (restricted)

Scored as

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Artificial Analysis index

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Output speed

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Hugging Face

closed weights

## Anthropic releases · around this one

Claude Opus 4.8

Closed

28 MAY 2026

index 174

Claude Fable 5

Closed

9 JUN 2026

index 185

Claude Mythos 5

Closed

9 JUN 2026

Claude Sonnet 5

Closed

30 JUN 2026

index 169

Claude Opus 5

Closed

24 JUL 2026

index 187

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Source: https://themodelindex.org/models/claude-mythos-5/ · The Model Index · data as of 2026-10-01