In short
How they differ.
Worked out from the figures below. Prices and specs are the makers' own, read Oct 20, 2026.
- Gemma 4 31B can be downloaded and run on your own machine; Claude Mythos 5.1 can't.
- No independent board we follow ranks both models yet.
Side by side
The specs.
| Claude Mythos 5.1 | Gemma 4 31B | |
|---|---|---|
| Made by | Anthropic · US | Google · US |
| Released | Sep 1, 2026 | Apr 2, 2026 |
| Price per 1M tokens | No public price | Free to download; hosts set prices |
| Context window | Not stated | 256K |
| Takes in | Not stated | text, image, video |
| Download and run it yourself | No | Yes (Apache 2.0) |
| Size | Not published | 30.7B (dense) parameters |
| Maker says | “Our most capable model for cybersecurity and biology research.” | “Today, we are introducing Gemma 4 — our most intelligent open models to date.” |
| Sources | Prices, Oct 20, 2026 · Description | Prices, Oct 20, 2026 · Description |
Independent tests
Where they place.
None of the boards we follow lists either model yet.
More comparisons