Model comparison

Claude Fable 5 vs Claude Fable 5.1

Price history, scores and specs for both models, line by line. Every value shows where it came from and when we last confirmed it.

Anthropic

Claude Fable 5

Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding.

20 checked values

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Anthropic

Claude Fable 5.1

Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors.

20 checked values

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Quick take

Where each one leads

Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index: 50 to 49.6.
Claude Fable 5.1 scores higher on the Artificial Analysis Coding Index: 81.6 to 76.5.
More people run Claude Fable 5.1 through OpenRouter than Claude Fable 5 right now.

Each line comes from a checked value in the tables below. Pick on your workload: price and usage matter for high volume, context and scores for long documents and agent loops.

Price history

Prices side by side, day by day

Input price history

Claude Fable 5 44 checked days, 3 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter models API
Claude Fable 5.1 44 checked days, 3 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter models API

Output price history

Claude Fable 5 44 checked days, 3 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter models API
Claude Fable 5.1 44 checked days, 3 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter models API

Prices are the listed OpenRouter base rates in US dollars. A day we could not confirm is left out of the line, never filled in.

Price

What each one costs now

Claude Fable 5 vs Claude Fable 5.1: What each one costs now
Measure	Claude Fable 5	Claude Fable 5.1
Input price	$10.00 per million tokensChecked 11 Nov 2026OpenRouter models API	$10.00 per million tokensChecked 11 Nov 2026OpenRouter models API
Output price	$50.00 per million tokensChecked 11 Nov 2026OpenRouter models API	$50.00 per million tokensChecked 11 Nov 2026OpenRouter models API

Scores

Benchmarks, with source and date

Claude Fable 5 vs Claude Fable 5.1: Benchmarks, with source and date
Measure	Claude Fable 5	Claude Fable 5.1
Artificial Analysis Intelligence Index	49.6Checked 27 Oct 2026Artificial Analysis via OpenRouter	50 LeadsChecked 11 Nov 2026Artificial Analysis via OpenRouter
Artificial Analysis Coding Index	76.5Checked 11 Nov 2026Artificial Analysis via OpenRouter	81.6 LeadsChecked 11 Nov 2026Artificial Analysis via OpenRouter
Artificial Analysis Agentic Index	50.7Checked 11 Nov 2026Artificial Analysis via OpenRouter	57.9 LeadsChecked 11 Nov 2026Artificial Analysis via OpenRouter
LMArena text rating (Elo)	1,492Checked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09	1,512 LeadsChecked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09
LMArena web development rating (Elo)	1,625Checked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09	1,742 LeadsChecked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09
LMArena vision rating (Elo)	1,326 LeadsChecked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09	1,322Checked 11 Nov 2026LMArena (CC-BY-4.0), published 2026-11-09
Design Arena rating (Elo)	1,329Checked 11 Nov 2026Design Arena via OpenRouter	1,397 LeadsChecked 11 Nov 2026Design Arena via OpenRouter

Specs

Context, modalities and tool use

Claude Fable 5 vs Claude Fable 5.1: Context, modalities and tool use
Measure	Claude Fable 5	Claude Fable 5.1
Context window	1,000,000 tokensChecked 11 Nov 2026OpenRouter models API	1,000,000 tokensChecked 11 Nov 2026OpenRouter models API
Reads	Text, Images, FilesChecked 11 Nov 2026OpenRouter models API	Text, Images, FilesChecked 11 Nov 2026OpenRouter models API
Writes	TextChecked 11 Nov 2026OpenRouter models API	TextChecked 11 Nov 2026OpenRouter models API
Tool calling	YesChecked 11 Nov 2026OpenRouter models API	YesChecked 11 Nov 2026OpenRouter models API
Reasoning mode	YesChecked 11 Nov 2026OpenRouter models API	YesChecked 11 Nov 2026OpenRouter models API
Open weights	NoChecked 11 Nov 2026OpenRouter models API	NoChecked 11 Nov 2026OpenRouter models API
Listed since	9 June 2026Checked 11 Nov 2026OpenRouter models API	1 Sept 2026Checked 11 Nov 2026OpenRouter models API

Usage

How much each one is used

Claude Fable 5 vs Claude Fable 5.1: How much each one is used
Measure	Claude Fable 5	Claude Fable 5.1
Tokens served on OpenRouter in a day	4.6B (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)	27.1B Leads (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)
Requests on OpenRouter in a day	63.1K (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)	229.3K Leads (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)
Tool calls on OpenRouter in a day	23.1K (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)	121.1K Leads (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)
Token usage, last 7 days	Down 54% on the week before (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)	Down 33% on the week before Leads (for 10 Nov 2026)Checked 11 Nov 2026OpenRouter model activity (748 of 748 series)

Tokens served a day on OpenRouter

Claude Fable 5 53 checked days, 19 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter model activity (748 of 748 series)
Claude Fable 5.1 53 checked days, 19 Sept 2026 to 10 Nov 2026. Checked 11 Nov 2026 · OpenRouter model activity (748 of 748 series)

How this works

One link, either order

This link stays the same whichever order you name the two models in, so you can share it as it is. A line appears only when at least one model has a value we confirmed from a source; values we have not confirmed are left out, never guessed. To add a third record of any type, use the open comparison. Read how we check facts.