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OpenAI

GPT-5.5 Pro

Benchmarks, price, context and versions

Also searched as

GPT 5.5 Pro, GPT-5.5-Pro

Direct answer: GPT-5.5 Pro is a model from OpenAI. 93.9% on GPQA Diamond, per Epoch AI. On OpenRouter, US$ 30.00 per 1 million input tokens and US$ 180.00 per 1 million output tokens.

✓ Good for

  • technical reasoning on science topics (#17 of 198 on GPQA Diamond)
  • calculation and problems with an exact answer (#11 of 186 on OTIS Mock AIME)
  • the ceiling of reasoning on research-level math (#10 of 86 on FrontierMath (tiers 1 to 3))
  • very long documents or code (a window of 1 million tokens or more, according to OpenRouter)

✕ Not the best for

  • when the input budget sits at the top of the table (input price in the highest 25% on OpenRouter)

This block follows a rule of this section, using source data: if the model is in the top 25% of the metric, the item goes under "Good for"; if it is in the bottom half, it goes under "Not the best for". The middle band appears in neither. Price and context use OpenRouter; scores use Epoch AI or OpenRouter Benchmarks, in the latest version we checked.

Benchmarks

GPQA Diamond

?what it is
93.9%

highest score on this metric 96.4%

17º / 198 · Epoch AI, latest version we checked

OTIS Mock AIME

?
100%

11º / 186 · Epoch AI, latest version we checked

FrontierMath (tiers 1 to 3)

?
87.7%

highest score on this metric 95.1%

10º / 86 · Epoch AI, latest version we checked

Key specs

Origin
the US
Family
GPT Pro provisional data
Weights?
closed
License
no data
Input US$/1M?
US$ 30.00
Output US$/1M
US$ 180.00
Context?
1,050,000 tokens
Parameters
no data
Input
file, image, text
OpenRouter usage?
no data
Downloads (30 days)?
no data
Use cases provisional data
Text Agents
Dates in sources
  • 2026, published, per Epoch AI
  • 2026, listed on OpenRouter

Version history

Dates come from the sources: OpenRouter listing or Hugging Face repo creation, which may differ from the official launch.

FAQ

What is GPT-5.5 Pro?

GPT-5.5 Pro is a model from OpenAI, with closed weights, used for text, agents.

How much does GPT-5.5 Pro cost?

On OpenRouter, US$ 30.00 per 1 million input tokens and US$ 180.00 per 1 million output tokens.

What is the context window of GPT-5.5 Pro?

1,050,000 tokens, per OpenRouter.

Is GPT-5.5 Pro open source?

No. It is available through API only.

What is GPT-5.5 Pro's GPQA Diamond score?

93.9% on GPQA Diamond, per Epoch AI.

Is GPT-5.5 Pro good for coding?

No data: there is no SWE-bench Verified measurement for it in open sources.

Who made GPT-5.5 Pro?

It was made by OpenAI, a lab from the US.

provisional data Questions under review: Semrush had no API balance during collection. Answers use source data only.

Models from OpenAI

See lab

Sources

  • Epoch AI, CC BY 4.0, latest version we checked.
  • OpenRouter, dados públicos da API; exports de benchmarks e rankings em CC BY 4.0, latest version we checked.

Dates come from the sources: OpenRouter listing or Hugging Face repo creation, which may differ from the official launch. Family and version were grouped by rule from the name.