Fable and Mythos 5.1 share exact same weights, differing only in classifier fallback
zsakib_ · x · 2026-09-02
A user corrected a previous claim that Fable was a distilled version of Mythos. It turns out Fable and Mythos 5.1 use the exact same weights. The difference lies in their safety handling: they inspect internal activations, escalate to a larger classifier if deemed dangerous, and ultimately fallback to Opus 4.8.
More from Models
- World Labs ships a new world model for 3D world generation — petewoodbridge · 2026-09-02
- 11 Frontier Models Take on Onchain Challenges: Best Scores Just 53% — davidfromkansas · 2026-09-02
- Testing Fable 5.1's ability to fix GitHub issues — Sauers_ · 2026-09-02
- Anthropic reveals Path to Astra: capabilities and frontier safeguards — pstAsiatech · 2026-09-02
- Anthropic releases Fable 5.1, demos generating Venus elevation maps — MaxLenormand · 2026-09-02
- Claude vs. ChatGPT comparison using leaked Fable 5.1 system prompt — seanmcdonaldxyz · 2026-09-02