The AI arena is free today

Open Superagent

Claude Fable 5 vs Claude Fable 5.1

Claude Fable 5 and Claude Fable 5.1 are closely matched at 55.1 and 54.8 on the LLM Stats Score. Claude Fable 5 and Claude Fable 5.1 cost the same.

Anthropic · Anthropic · Updated for 2026

Which is better?

Claude Fable 5 and Claude Fable 5.1 are closely matched on the overall LLM Stats Score at 55.1 and 54.8.

In the 2 individual benchmarks reported for both models, Claude Fable 5.1 wins 2; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Fable 5

  • you want predictable pricing at $10.00/M input and $50.00/M output

Choose Claude Fable 5.1

  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Claude Fable 5
Anthropic
Claude Fable 5.1
Anthropic
Core performance indexes
LLM Stats Score
55.1
#4
54.8
#5
Reasoning
52.4
#6
52.1
#7
Agents
40.9
#2
39.3
#6
Cost, coverage & limits
Benchmark wins
0 of 2
2 of 2
Input price
$10.00 / M
$10.00 / M
Output price
$50.00 / M
$50.00 / M
Context window
1,000,000
1,000,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Fable 5
Claude Fable 5.1
Vision
36.6#7
40.5#1
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

18 reported for Claude Fable 5 · 7 for Claude Fable 5.1

2 shared

Claude Fable 5 outperforms in 0 benchmarks, while Claude Fable 5.1 is better at 2 benchmarks (AutomationBench, Humanity's Last Exam).

Claude Fable 5.1 significantly outperforms across most benchmarks.

Wed Sep 02 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

For input processing, Claude Fable 5 ($10.00/1M tokens) costs the same as Claude Fable 5.1 ($10.00/1M tokens).

For output processing, Claude Fable 5 ($50.00/1M tokens) costs the same as Claude Fable 5.1 ($50.00/1M tokens).

In conclusion, Claude Fable 5 and Claude Fable 5.1 cost the same.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Sep 02 2026 • llm-stats.com
Anthropic
Claude Fable 5
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Anthropic
Claude Fable 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Both models have the same input context window of 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Fable 5
Input1,000,000 tokens
Output128,000 tokens
Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Wed Sep 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Fable 5 and Claude Fable 5.1 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Fable 5

Text
Images
Audio
Video

Claude Fable 5.1

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Fable 5

Proprietary

Closed source

Claude Fable 5.1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Fable 5 was released on 2026-06-09, while Claude Fable 5.1 was released on 2026-09-01.

Claude Fable 5.1 is 3 months newer than Claude Fable 5.

Claude Fable 5

Jun 9, 2026

2 months ago

Claude Fable 5.1

Sep 1, 2026

0 days ago

2mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Fable 5 is available from Anthropic. Claude Fable 5.1 is available from Anthropic.

Claude Fable 5

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

Claude Fable 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Fable 5 and Claude Fable 5.1 side-by-side, then vote on the output you prefer.

Claude Fable 5
✓ Preferred
Claude Fable 5.1
Open in Playground

FAQ

Common questions about Claude Fable 5 vs Claude Fable 5.1.

Which is better, Claude Fable 5 or Claude Fable 5.1?

Claude Fable 5 and Claude Fable 5.1 are closely matched on the LLM Stats Score at 55.1 and 54.8. Claude Fable 5 is made by Anthropic and Claude Fable 5.1 is made by Anthropic. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Fable 5 compare to Claude Fable 5.1 in benchmarks?

Claude Fable 5 scores SWE-Bench Verified: 95.0%, FrontierSWE: 90.0%, OSWorld-Verified: 85.0%, Terminal-Bench 2.1: 84.3%, SWE-Bench Pro: 80.0%. Claude Fable 5.1 scores OSWorld 2.0: 77.9%, CursorBench v3.2: 73.4%, Humanity's Last Exam: 65.0%, GDPval-AA: 61.8%, Terminal-Bench 4.0: 55.8%.

Is Claude Fable 5 cheaper than Claude Fable 5.1?

Both models cost $10.00 per million input tokens.

What are the context window sizes for Claude Fable 5 and Claude Fable 5.1?

Claude Fable 5 supports 1.0M tokens and Claude Fable 5.1 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Fable 5 and Claude Fable 5.1?

Key differences include LLM Stats Score (55.1 vs 54.8). See the full comparison above for benchmark-by-benchmark results.

Related comparisons