AnthropicClaude Fable 5VSOpenAIGPT-5.5

Analysis by:the whichllmmodel Editorial Team|Updated: June 2026

Our Take

If your budget allows, Claude Fable 5 is the superior choice here, offering a clear benchmark advantage while carrying only a moderate price premium (1.8x). We recommend choosing GPT-5.5 only if you need to optimize costs for very high-volume pipelines.

Was this recommendation helpful?

Model Specs

Claude Fable 5

Website

Benchmarks & Scores

Coding (swe-bench-pro)Winner (+21.7%)

80.3%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)Winner (+0.5%)

94.1%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)

$20.00Input: $10.00 | Output: $50.00

Context Window

1.05M tokens

Model Specs

GPT-5.5

Website

Benchmarks & Scores

Coding (swe-bench-pro)

58.6%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)

93.6%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)1.8x cheaper

$11.25Input: $5.00 | Output: $30.00

Context WindowLarger

1.05M tokens

Read our data collection methodology

Frequently Asked Questions about Claude Fable 5 vs GPT-5.5

GPT-5.5 is cheaper than Claude Fable 5. GPT-5.5 has a blended cost of $11.25/1M tokens, which is about 1.8x cheaper than Claude Fable 5 at $20.00/1M tokens.

Claude Fable 5 is better for coding tasks on this benchmark. It scores 80.3% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) compared to GPT-5.5 which scores 58.6%.

Related Matchups

Explore similar comparisons for Claude Fable 5 and GPT-5.5.

Browse More Comparisons

AnthropicClaude Fable 5

AnthropicClaude Fable 5

OpenAIGPT-5.6 Luna

Compare Specs

Do you want to find a model for your constraints?

Use our interactive model finder to filter LLMs by reasoning capability, coding performance, cost, and context length.

Open Model Finder