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Claude 3.7 Sonnet vs Claude Fable 5.1

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 24.2. Claude 3.7 Sonnet is 3.3x cheaper per token.

Anthropic · Anthropic · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 54.8 to 24.2, ranking #5 overall.

On price, Claude 3.7 Sonnet is roughly 3.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Fable 5.1 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose Claude 3.7 Sonnet

  • cost matters — it's about 3.3x cheaper per token

Choose Claude Fable 5.1

  • overall performance matters — it scores 54.8 and ranks #5 on LLM Stats
  • your work emphasizes reasoning and agents — it leads those capability indexes
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Claude 3.7 Sonnet
Anthropic
Claude Fable 5.1
Anthropic
Core performance indexes
LLM Stats Score
24.2
#155
54.8
#5
Reasoning
23.3
#154
52.1
#7
Agents
5.2
#136
39.3
#6
Cost, coverage & limits
Benchmark wins
—
—
Input price
$3.00 / M
$10.00 / M
Output price
$15.00 / M
$50.00 / M
Context window
200,000
1,000,000

Individual benchmarks

11 reported for Claude 3.7 Sonnet · 7 for Claude Fable 5.1

No common benchmarks found

Claude 3.7 Sonnet and Claude Fable 5.1don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Claude 3.7 Sonnet costs less

For input processing, Claude 3.7 Sonnet ($3.00/1M tokens) is 3.3x cheaper than Claude Fable 5.1 ($10.00/1M tokens).

For output processing, Claude 3.7 Sonnet ($15.00/1M tokens) is 3.3x cheaper than Claude Fable 5.1 ($50.00/1M tokens).

In conclusion, Claude Fable 5.1 is more expensive than Claude 3.7 Sonnet.*

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

Lowest available price from all providers
Tue Sep 01 2026 • llm-stats.com
Anthropic
Claude 3.7 Sonnet
Input tokens$3.00
Output tokens$15.00
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

Claude Fable 5.1 accepts 1,000,000 input tokens compared to Claude 3.7 Sonnet's 200,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude 3.7 Sonnet
Input200,000 tokens
Output128,000 tokens
Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Tue Sep 01 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude 3.7 Sonnet and Claude Fable 5.1 support multimodal inputs.

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

Claude 3.7 Sonnet

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 3.7 Sonnet

Proprietary

Closed source

Claude Fable 5.1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3.7 Sonnet was released on 2025-02-24, while Claude Fable 5.1 was released on 2026-09-01.

Claude Fable 5.1 is 18 months newer than Claude 3.7 Sonnet.

Claude 3.7 Sonnet

Feb 24, 2025

1.5 years ago

Claude Fable 5.1

Sep 1, 2026

0 days ago

1.5yr 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 3.7 Sonnet is available from Anthropic, Bedrock, Google. Claude Fable 5.1 is available from Anthropic.

Claude 3.7 Sonnet

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
google logo
Google
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

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 3.7 Sonnet and Claude Fable 5.1 side-by-side, then vote on the output you prefer.

Claude 3.7 Sonnet
✓ Preferred
Claude Fable 5.1
Open in Playground

FAQ

Common questions about Claude 3.7 Sonnet vs Claude Fable 5.1.

Which is better, Claude 3.7 Sonnet or Claude Fable 5.1?

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 24.2. Claude 3.7 Sonnet 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 3.7 Sonnet compare to Claude Fable 5.1 in benchmarks?

Claude 3.7 Sonnet scores MATH-500: 96.2%, IFEval: 93.2%, MMMLU: 86.1%, GPQA: 84.8%, TAU-bench Retail: 81.2%. 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 3.7 Sonnet cheaper than Claude Fable 5.1?

Claude 3.7 Sonnet is 3.3x cheaper for input tokens. Claude 3.7 Sonnet costs $3.00/M input and $15.00/M output via anthropic. Claude Fable 5.1 costs $10.00/M input and $50.00/M output via anthropic.

What are the context window sizes for Claude 3.7 Sonnet and Claude Fable 5.1?

Claude 3.7 Sonnet supports 200K 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 3.7 Sonnet and Claude Fable 5.1?

Key differences include LLM Stats Score (24.2 vs 54.8), context window (200K vs 1.0M), input pricing ($3.00 vs $10.00/M). See the full comparison above for benchmark-by-benchmark results.

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