Claude Mythos 5.1 vs Gemini 3.1 Pro
Claude Mythos 5.1 leads the LLM Stats Score 45.1 to 43.4. Gemini 3.1 Pro is 4.4x cheaper per token.
Anthropic · Google · Updated for 2026
Which is better?
Claude Mythos 5.1 leads the overall LLM Stats Score 45.1 to 43.4, ranking #31 overall.
On price, Gemini 3.1 Pro is roughly 4.4x 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 Mythos 5.1
- overall performance matters — it scores 45.1 and ranks #31 on LLM Stats
- your work emphasizes coding and agents — it leads those capability indexes
- you want the most recent training data — it shipped Sep 2026
Choose Gemini 3.1 Pro
- cost matters — it's about 4.4x cheaper per token
At a glance
The differences that matter most.
Individual benchmarks
1 reported for Claude Mythos 5.1 · 20 for Gemini 3.1 Pro
Claude Mythos 5.1 and Gemini 3.1 Prodon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 5.0x more expensive than Gemini 3.1 Pro ($2.00/1M tokens).
For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 4.2x more expensive than Gemini 3.1 Pro ($12.00/1M tokens).
In conclusion, Claude Mythos 5.1 is more expensive than Gemini 3.1 Pro.*
* 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. Gemini 3.1 Pro can generate longer responses up to 1,000,000 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Mythos 5.1 and Gemini 3.1 Pro support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Mythos 5.1
Gemini 3.1 Pro
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 Mythos 5.1 was released on 2026-09-01, while Gemini 3.1 Pro was released on 2026-02-19.
Claude Mythos 5.1 is 6 months newer than Gemini 3.1 Pro.
Sep 1, 2026
1 weeks ago
6mo newerFeb 19, 2026
6 months ago
Knowledge Cutoff
When training data ends
Gemini 3.1 Pro has a documented knowledge cutoff of 2025-01-31, while Claude Mythos 5.1's cutoff date is not specified.
We can confirm Gemini 3.1 Pro's training data extends to 2025-01-31, but cannot make a direct comparison without Claude Mythos 5.1's cutoff date.
—
Jan 2025
Provider Availability
Claude Mythos 5.1 is available from Anthropic. Gemini 3.1 Pro is available from DeepInfra, Google.
Claude Mythos 5.1
Gemini 3.1 Pro
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos 5.1 and Gemini 3.1 Pro side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos 5.1 vs Gemini 3.1 Pro.