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GPT-5 Nano vs GPT-5.5

Head to head on 23 shared benchmarks, with price, context window, and release dates.

Benchmark scores

78

evals · sort by any column, ⤢ to expand fullscreen

Model
GPT-5.5

OpenAI

1844elo78.251.7%76.8%13.7%46.1%84.7%82.5%81.1%73.0%87.7%96.3%87.7%49.1%86.9%88.6%68.8%50.0%51.5%47.3%75.0%49.2%69.3%--86.2%54.2%12.9%--36.2%-68.4%86.0%90.0%100.0%-1315elo34.0%51.8%-5.7%44.8%-24.9%1769elo15.1%-51.8%2.1%-----92.8%---78.7%45.3%100.0%-4.2--58.6%75.7%83.4%-57.4%68.1%--69.8%---61.9%
GPT-5 Nano

OpenAI

703elo288.3%42.8%4.0%32.5%52.8%62.4%43.4%55.7%46.8%68.4%40.3%30.4%72.9%55.6%53.6%12.0%30.4%29.1%67.4%6.8%25.7%0.0%27.3%---0.250.21-6.7%----10.0%---78.2%--1.18---100.0%--47.0%1.381.38100.0%100.0%-26.7%100.0%0.0%---0.0%-1.7234.8%---29.7%--20.41-6.67-82.0%82.0%40.0%43.7%
2 / 2 models
AttributeGPT-5 Nano

OpenAI

GPT-5.5

OpenAI

DescriptionGPT-5 nano is an AI model from OpenAI.GPT-5.5 is an AI model from OpenAI.
FamilyGPTGPT
Params--
Open weightsclosedclosed
Licenseproprietaryproprietary
Released7 Aug 202523 Apr 2026
Context400,0001,050,000
Input $/1M$0.05$5.00
Output $/1M$0.40$30.00
Cache read $/1M$0.005$0.500
Cache write $/1M--
Speed0 tok/s0 tok/s
Latency0.00 s0.00 s
Modalitiestext, image, filefile, image, text
Providers--
PublisherOpenAIOpenAI
Reported scores

FAQ

Is GPT-5 Nano or GPT-5.5 better?
Across the 23 benchmarks both models report on Sophon, GPT-5.5 leads on 23 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do GPT-5 Nano and GPT-5.5 compare on GPQA Diamond?
GPT-5 Nano scores 42.8% and GPT-5.5 scores 76.8% on GPQA Diamond.
Which is cheaper, GPT-5 Nano or GPT-5.5?
GPT-5 Nano is cheaper at $0.40 per million output tokens against $30.00 for GPT-5.5 - about 75.0x.
When were GPT-5 Nano and GPT-5.5 released?
GPT-5 Nano was released 7 Aug 2025 by OpenAI. GPT-5.5 was released 23 Apr 2026 by OpenAI.

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