Claude Fable 5.1 tops Artificial Analysis Index but costs 20% more
. Claude Fable 5.1 tops Artificial Analysis Index but costs 20% more Why it matters for engineering teams What shipped and who is affected.
By Dillip Chowdary • Oct 09, 2026 • Source: HN Claude/Codex/Fable
What shipped in Claude Fable 5.1 tops Artificial Analysis
HN Claude/Codex/Fable reports: Claude Fable 5.1 tops Artificial Analysis Index but costs 20% more. Article URL: https://twitter.com/ArtificialAnlys/status/2094881171066978525 Comments URL: https://news.ycombinator.com/item?id=49532294 Points: 1 # Comments: 0
What improved in Claude Fable 5.1 tops Artificial Analysis
Artificial Analysis@ArtificialAnlysClaude Fable 5.1 tops the Artificial Analysis Intelligence Index but costs 20% more per task than Fable 5 despite a 75% cache read price cut We supported @AnthropicAI with pre-release evaluation of Claude Fable 5.1. At max effort it scores 66 on the Artificial Analysis Intelligence Index, the highest score we have measured, ahead of Claude Opus 5 (max, 63), Claude Fable 5 (max, 62), GPT-5.6 Sol (max, 61) and Grok 4.6 (high, 61).
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What you gain from Claude Fable 5.1 tops Artificial Analysis
We evaluated the model with Anthropic's ‘default’ server-side fallback, which routes safety-flagged requests to Claude Opus 4.8 or Claude Opus 5; fallback served ~4% of output tokens across the Intelligence Index. Key takeaways ➤ Frontier Intelligence with improvements across benchmarks: Fable 5.1 gains +4 points on the Intelligence Index over Fable 5.
How to get Claude Fable 5.1 tops Artificial Analysis
On HLE, Fable 5.1 scores 59.1%, ahead of the previous best of 55.5% from Claude Fable 5. See the full write-up from HN Claude/Codex/Fable via the source link for quotes and complete context.
What to watch after Claude Fable 5.1 tops Artificial Analysis
Fable 5.1 (max) costs $3.76 per Intelligence Index task, 20% more than Fable 5 (max), because it uses ~1.7x the output tokens. The cache cut saves ~$1.40 per task, concentrated in the agentic evaluations where the majority of input tokens are cache reads.
Developer Action Items
- ☐ Verify the claim on the official Anthropic / Claude / Opus page (or HN Claude/Codex/Fable), not from this recap alone.
- ☐ Name the surface that moved — API, policy, model, hardware, or commercial terms — before you Slack the thread.
- ☐ Assign one owner a day to read the primary material and decide: this-sprint, this-quarter, or noise.
- ☐ Do not change production on day-one coverage. Watch the vendor changelog and one independent write-up first.
Author
Dillip Chowdary
Writes Tech Bytes coverage of AI, engineering, and the tools that actually ship. Editor of Tech Pulse Daily.
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