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OpenAIGPT-5.4 ProVSOpenAIGPT-5.5

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

Our Take

Standardized reasoning and coding benchmarks are currently pending verification for one or both of these models. We recommend testing GPT-5.4 Pro and GPT-5.5 directly in their respective provider playgrounds to see which fits your specific prompt styles best.
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Model Specs

GPT-5.4 Pro

Benchmarks & Scores

Coding (swe-bench-pro)
N/A

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

Reasoning (gpqa-diamond)
67.6%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)81.8x cheaper
$0.14Input: $0.05 | Output: $0.40
Context Window
400k tokens
Model Specs

GPT-5.5

Benchmarks & Scores

Coding (swe-bench-pro)
58.6%

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

Reasoning (gpqa-diamond)Winner (+26.0%)
93.6%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)
$11.25Input: $5.00 | Output: $30.00
Context WindowLarger
1.05M tokens

Frequently Asked Questions about GPT-5.4 Pro vs GPT-5.5

GPT-5.4 Pro is cheaper than GPT-5.5. GPT-5.4 Pro has a blended cost of $0.14/1M tokens, which is about 81.8x cheaper than GPT-5.5 at $11.25/1M tokens.

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