Claude Fable 5.1 vs GPT-4o

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 14.4. GPT-4o is 4.6x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 54.8 to 14.4, ranking #5 overall.

In the 1 individual benchmarks reported for both models, Claude Fable 5.1 wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, GPT-4o is roughly 4.6x 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 Fable 5.1

overall performance matters — it scores 54.8 and ranks #5 on LLM Stats
your work emphasizes reasoning — it leads those capability indexes
you value its reported benchmark strengths — it wins 1 of 1 exact shared results
you process long inputs — it offers a 1,000,000 token context window
you want the most recent training data — it shipped Sep 2026

Choose GPT-4o

cost matters — it's about 4.6x cheaper per token

At a glance

The differences that matter most.

Better token value: GPT-4o

Core performance indexes

LLM Stats Score

54.8

#5 · 4 evals

Best

14.4

#222 · 37 evals

Reasoning

52.1

#7 · 3 evals

Best

16.1

#204 · 31 evals

Cost, coverage & limits

Benchmark wins

1 of 1

Best

0 of 1

Input price

$10.00 / M

$2.50 / M

Best

Output price

$50.00 / M

$10.00 / M

Best

Context window

1,000,000

Best

128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared

Index

Claude Fable 5.1

GPT-4o

Vision

40.5#1 · 2 evals

8.9#126 · 12 evals

Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for Claude Fable 5.1 · 38 for GPT-4o

1 shared

Claude Fable 5.1 outperforms in 1 benchmarks (Humanity's Last Exam), while GPT-4o is better at 0 benchmarks.

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

GPT-4o costs less

For input processing, Claude Fable 5.1 ($10.00/1M tokens) is 4.0x more expensive than GPT-4o ($2.50/1M tokens).

For output processing, Claude Fable 5.1 ($50.00/1M tokens) is 5.0x more expensive than GPT-4o ($10.00/1M tokens).

In conclusion, Claude Fable 5.1 is more expensive than GPT-4o.*

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

Lowest available price from all providers

Wed Sep 02 2026 • llm-stats.com

Claude Fable 5.1

Input tokens$10.00

Output tokens$50.00

Best providerAnthropic

GPT-4o

Input tokens$2.50

Output tokens$10.00

Best providerAzure

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 GPT-4o's 128,000 tokens. Claude Fable 5.1 can generate longer responses up to 128,000 tokens, while GPT-4o is limited to 16,384 tokens.

Claude Fable 5.1

Input1,000,000 tokens

Output128,000 tokens

GPT-4o

Input128,000 tokens

Output16,384 tokens

Wed Sep 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Fable 5.1 and GPT-4o support multimodal inputs.

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

Claude Fable 5.1

Text

Images

Audio

Video

GPT-4o

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 5.1

Proprietary

Closed source

GPT-4o

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while GPT-4o was released on 2024-08-06.

Claude Fable 5.1 is 25 months newer than GPT-4o.

Claude Fable 5.1

Sep 1, 2026

1 days ago

2.1yr newer

GPT-4o

Aug 6, 2024

2.1 years ago

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 5.1 is available from Anthropic. GPT-4o is available from Azure, OpenAI.

Claude Fable 5.1

Anthropic

Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

GPT-4o

Azure

Input Price:Input: $2.50/1MOutput Price:Output: $10.00/1M

OpenAI

Input Price:Input: $2.50/1MOutput Price:Output: $10.00/1M

* 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 5.1 and GPT-4o side-by-side, then vote on the output you prefer.

Claude Fable 5.1

✓ Preferred

GPT-4o

Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs GPT-4o.

Which is better, Claude Fable 5.1 or GPT-4o?

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 14.4. Claude Fable 5.1 is made by Anthropic and GPT-4o is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Fable 5.1 compare to GPT-4o in benchmarks?

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%. GPT-4o scores AI2D: 94.2%, DocVQA: 92.8%, ChartQA: 85.7%, MMLU: 85.7%, CharXiv-D: 85.3%.

Is Claude Fable 5.1 cheaper than GPT-4o?

GPT-4o is 4.0x cheaper for input tokens. Claude Fable 5.1 costs $10.00/M input and $50.00/M output via anthropic. GPT-4o costs $2.50/M input and $10.00/M output via azure.

What are the context window sizes for Claude Fable 5.1 and GPT-4o?

Claude Fable 5.1 supports 1.0M tokens and GPT-4o supports 128K 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 5.1 and GPT-4o?

Key differences include LLM Stats Score (54.8 vs 14.4), context window (1.0M vs 128K), input pricing ($10.00 vs $2.50/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and GPT-4o?

Claude Fable 5.1 is developed by Anthropic and GPT-4o is developed by OpenAI.

Claude Fable 5.1 vs GPT-4o