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#264

Claude Fable 5.1

Anthropic Release: 2026-09-02 Tested on: 2026-10-01 04:20 anthropic/claude-fable-5.1::low
~9.5T total (~878B active)MoEClosedEstimated
(high) (medium) (low)

Summary

Claude Fable 5.1 scores 6.2 on AI BENCHY and ranks #264. It has 10.0 reliability, a 55.1% pass rate, $3.395 total cost, and 11.40s average response time.

What makes Claude Fable 5.1 unique: It stands out most in Combined, where it ranks #1, while Agentic is its weakest area at #15.

Model facts

Researched on 2026-09-02

Estimated
Parameters
~9.5T total (~878B active)
Architecture
MoE
Availability
Closed
License
-

Best estimate from public evidence; the vendor did not disclose every value. Anthropic does not disclose parameter counts or architecture; estimates follow the Claude Fable 5 family record.

Parameter source Availability source

Score

6.2

Consistency

8.9

Reliability

10.0

Total Cost (Current Price)

$3.395

Total Output Tokens

26,073

Total Input Tokens

209,116

Input Price

$10.000 / 1M

Output Price

$50.000 / 1M

Cache Read Price

$0.250 / 1M

Cache Write Price

$12.500 / 1M

Cache prices apply to input tokens. Reads reuse cached prompts; writes store them and can cost extra. Output tokens use the output price.

Tests Correct

Wrong Tests: 12

Attempt pass rate: 55.1%

Flaky tests

3

Flaky tests had mixed outcomes across runs (at least one pass and one fail).

Response Time (avg)

11.40s

Response Time (max): 34.77s

Response Time (total): 262.14s

Extra formatting: 4 Wrong answer: 4 Did not follow instructions: 3 API error: 1

Hamster playing table tennis

Prompt: Create a detailed SVG illustration of a hamster playing table tennis.

#264 Claude Fable 5.1

low
Cost
$0.126
Time
28.5s
Tokens
2,652 tok

Price History

Historical pricing data for this model from OpenRouter.

Date Input Price Output Price Cache Read Price Cache Write Price
2026-10-01 18:33 $10.000 / 1M $50.000 / 1M $0.250 / 1M $12.500 / 1M

Charts

Choose the first model, then click a second model to open a side-by-side page.

Total Output Tokens

Score vs Total Output Tokens

Quick Compare

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Category Breakdown

Category Score Consistency Tests Correct
Agentic 2.8 1.6
Anti-AI Tricks 6.5 10.0
Coding 3.4 10.0
Combined 10.0 10.0
Data parsing and extraction 10.0 10.0
Domain specific 4.1 4.4
General Intelligence 10.0 10.0
Instructions following 6.5 10.0
Puzzle Solving 7.7 10.0
Tool Calling 10.0 10.0
Trivia 3.0 10.0

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