Claude Mythos Preview vs Gemini 3.1 Pro
Claude Mythos Preview significantly outperforms across most benchmarks. Gemini 3.1 Pro is 8.9x cheaper per token.
Anthropic · Google · Updated for 2026
Which is better?
Claude Mythos Preview outperforms in 7 benchmarks (BrowseComp, GPQA, Humanity's Last Exam, MMMLU, SWE-Bench Pro, SWE-Bench Verified, Terminal-Bench 2.0), while Gemini 3.1 Pro is better at 0 benchmarks. Claude Mythos Preview significantly outperforms across most benchmarks.
On price, Gemini 3.1 Pro is roughly 8.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current benchmark, pricing, and model metadata for 2026.
Choose Claude Mythos Preview
- you want the strongest raw capability — it leads on 7 of 7 shared benchmarks
Choose Gemini 3.1 Pro
- cost matters — it's about 8.9x cheaper per token
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
Claude Mythos Preview outperforms in 7 benchmarks (BrowseComp, GPQA, Humanity's Last Exam, MMMLU, SWE-Bench Pro, SWE-Bench Verified, Terminal-Bench 2.0), while Gemini 3.1 Pro is better at 0 benchmarks.
Claude Mythos Preview significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Mythos Preview ($25.00/1M tokens) is 10.0x more expensive than Gemini 3.1 Pro ($2.50/1M tokens).
For output processing, Claude Mythos Preview ($125.00/1M tokens) is 8.3x more expensive than Gemini 3.1 Pro ($15.00/1M tokens).
In conclusion, Claude Mythos Preview 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
Only Gemini 3.1 Pro specifies input context (1,048,576 tokens). Only Gemini 3.1 Pro specifies output context (65,536 tokens).
Input Capabilities
Supported data types and modalities
Both Claude Mythos Preview and Gemini 3.1 Pro support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Mythos Preview
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
Gemini 3.1 Pro was released on 2026-02-19, while Claude Mythos Preview's release date is not specified.
We can confirm Gemini 3.1 Pro's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.
—
Feb 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 Preview'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 Preview's cutoff date.
—
Jan 2025
Provider Availability
Claude Mythos Preview is available from Anthropic. Gemini 3.1 Pro is available from Google.
Claude Mythos Preview
Gemini 3.1 Pro
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos Preview and Gemini 3.1 Pro side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos Preview vs Gemini 3.1 Pro.