Claude Fable 5.1 holds #1: 1M-token input, ties GPT 6 Astra on new benchmarks
DeepLearningAI · x · 2026-09-15
DeepLearning.AI's The Batch breaks down Anthropic's Claude Fable 5.1: Fable and Claude Mythos 5.1 are the same model differing only in safeguards — Fable is open to everyone, Mythos restricted to US cybersecurity/life-sciences orgs via Project Glasswing, with fallback to Opus 4.8/5 when bio/cyber classifiers trigger.
- Specs: text+image input up to 1M tokens, output up to 128k tokens at 69 tokens/sec, June 2026 knowledge cutoff
- Features: always-on reasoning with five levels (switchable mid-conversation without invalidating cache, beta), tool use with readable progress, prompt caching, per-turn system messages, statistical watermarking
- Scores: ties for first on Artificial Analysis Intelligence Index v4.3 (53), leads Vals AI (68.83%), scores 57 on v4.2 edging out GPT 6 Astra, 52.6% on Terminal Bench Science 0.1
- Cost: cheaper cache reads for repeated agentic workflows; available via Claude.ai, API, AWS, Google Cloud, Azure
More from Models
- Claude upgrade-page traffic rebounded to 17.6M in September, near May's 18.6M peak — firstadopter · 2026-11-02
- Open-source GLiNER-PII scrubs 13 identifiers from a discharge note in 550ms on GPU — MaziyarPanahi · 2026-11-02
- OpenAI Dots user says bloat and broken infra drove him to try newcomer Muse — Koala_Confused · 2026-11-02
- Fable 5.5 reportedly one-shots animation in pure code as Anthropic's coding bet pays off — Hesamation · 2026-11-02
- One agent goal has been running for 4 days, burning 30K tokens — CtrlAltDwayne · 2026-11-02
- Daily AI Brief: Gemini 4 Carbon spotted on Arena, DeepSeek open-sources coding agent — testingcatalog · 2026-11-02