Claude Fable 5.2 vs Claude Mythos 5.1
Claude Fable 5.2 leads the LLM Stats Score 61.3 to 43.0. Claude Fable 5.2 is 1.3x cheaper per token.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Fable 5.2 leads the overall LLM Stats Score 61.3 to 43.0, ranking #1 overall.
In the 1 individual benchmarks reported for both models, Claude Fable 5.2 wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, Claude Fable 5.2 is roughly 1.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Fable 5.2
- overall performance matters — it scores 61.3 and ranks #1 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- cost matters — it's about 1.3x cheaper per token
- you want the most recent training data — it shipped Nov 2026
Choose Claude Mythos 5.1
- you want predictable pricing at $10.00/M input and $50.00/M output
At a glance
The differences that matter most.
Individual benchmarks
29 reported for Claude Fable 5.2 · 1 for Claude Mythos 5.1
Claude Fable 5.2 outperforms in 1 benchmarks (Terminal-Bench 4.0), while Claude Mythos 5.1 is better at 0 benchmarks.
Claude Fable 5.2 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Fable 5.2 ($8.00/1M tokens) is 1.3x cheaper than Claude Mythos 5.1 ($10.00/1M tokens).
For output processing, Claude Fable 5.2 ($40.00/1M tokens) is 1.3x cheaper than Claude Mythos 5.1 ($50.00/1M tokens).
In conclusion, Claude Mythos 5.1 is more expensive than Claude Fable 5.2.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Fable 5.2 and Claude Mythos 5.1 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Fable 5.2
Claude Mythos 5.1
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Fable 5.2 was released on 2026-11-09, while Claude Mythos 5.1 was released on 2026-09-01.
Claude Fable 5.2 is 2 months newer than Claude Mythos 5.1.
Nov 9, 2026
3 days ago
2mo newerSep 1, 2026
2 months ago
Knowledge Cutoff
When training data ends
Claude Fable 5.2 has a documented knowledge cutoff of 2026-06-01, while Claude Mythos 5.1's cutoff date is not specified.
We can confirm Claude Fable 5.2's training data extends to 2026-06-01, but cannot make a direct comparison without Claude Mythos 5.1's cutoff date.
Jun 2026
—
Provider Availability
Claude Fable 5.2 is available from Anthropic. Claude Mythos 5.1 is available from Anthropic.
Claude Fable 5.2
Claude Mythos 5.1
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Fable 5.2 and Claude Mythos 5.1 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Fable 5.2 vs Claude Mythos 5.1.