[whatmodel.sh](../../README.md) / GPT-5.5 Pro # GPT-5.5 Pro OpenAI · released 2026-04 · closed weights **score 80.1** ±1.1 · #12 of 732 · from 5 benchmark results across 2 sources Score within the [LMArena (text)](https://whatmodel.sh/?set=lmarena-text&score=set) comparison set only. ## What it's good at ● marks GPT-5.5 Pro among every model on that task or test, worst to best. 
task         vs the others         rank  counts  tests
agent tasks  ▁▁▃▆█▄▅▅▄▄●▁   #14 of 313*     15%      2
math         ▁▁▃▅█▆▄█▄▂●▁   #10 of 431*     70%      2
web search   ▁▁▁▅▄█▃●·▁·▁    #15 of 84*     15%      2
agent tasks · #14 of 313 · 15% of its score Trails [Claude Mythos Preview (limited preview)](claude-mythos-preview.md), [Claude Fable 5](claude-fable-5.md) here, though they rank lower overall. 
test                                result  vs the others in its run  difficulty           counts  why
Humanity's Last Exam with tools (…   57.2%  ▃·▃·▅····▅·● beats 6/8    very hard · avg 12%    7.9%  at its level
BrowseComp (maker)                   90.1%  ▄··█▄··▄·▄●▄ beats 6/8    medium · avg 38%       7.5%  typical
math · #10 of 431 · 70% of its score Beats [Claude Opus 5](claude-opus-5.md) here, though they rank higher overall. Trails [Claude Fable 5](claude-fable-5.md), [GPT-5.6 Sol](gpt-5-6-sol.md) here, though they rank lower overall. 
test                       result  vs the others in its run  difficulty            counts  why
FrontierMath tier 4 v2      78.0%  ▁▂▁▂█▅▂●▂▁▁▁ beats 58/67  very hard · avg 0.1%     43%  sharp · at its level
FrontierMath tiers 1–3 v2   87.7%  ▂··▁▁▃▄▄█▆●▃ beats 78/86  very hard · avg 1.2%     27%  sharp
web search · #15 of 84 · 15% of its score Beats [Claude Fable 5.1](claude-fable-5-1.md), [Claude Sonnet 5.5](claude-sonnet-5-5.md), [Claude Opus 5](claude-opus-5.md) here, though they rank higher overall. Trails [GPT-4o mini (2024-07-18)](gpt-4o-mini-2024-07-18.md), [Mistral Small 3.1 24B (2503)](mistral-small-3-1.md), [GPT-4o (2024-08-06)](gpt-4o-2024-08-06.md) here, though they rank lower overall. 
test                                result  vs the others in its run  difficulty           counts  why
Humanity's Last Exam with tools (…   57.2%  ▃·▃·▅····▅·● beats 6/8    very hard · avg 12%    7.9%  at its level
BrowseComp (maker)                   90.1%  ▄··█▄··▄·▄●▄ beats 6/8    medium · avg 38%       7.5%  typical
other tests (1) 
test                          result  vs the others in its run  difficulty            counts  why
Humanity's Last Exam (maker)   43.1%  ▃··▃·▃▃···▃● beats 7/7    very hard · avg 4.4%     14%  at its level
## How the score was worked out Each result implies a score on its own, after adjusting for how hard that test is and who ran it. The model's score is their weighted average, with a small pull toward the middle for thinly tested models. Each test's weight is its *counts* column above; here it is added up by who ran the tests. [Method](../method.md) 
source                                    results  share of the score
Epoch AI                                        2   70% ▇▇▇▇▇▇▇▇
OpenAI vendor-reported benchmark scores…        3   30% ▇▇▇▇
prior: pull toward the middle                        1% ▇
weighted average                                   = 80.1
Licences: Epoch AI ([CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)) ## How to run it ### Through an API api (OpenAI) · $67.50/M blended · $30 in / $180 out per 1M tokens · [developers.openai.com](https://developers.openai.com/api/docs/models/gpt-5.5-pro) [price source](https://developers.openai.com/api/docs/models/gpt-5.5-pro): USD per 1M tokens, OpenAI API standard processing for gpt-5.5-pro (Responses API; also Batch): input $30.00, output $180.00; no cached-input discount; Batch API pricing and the 10% regional-processing (data residency) uplift excluded. Currency: USD. OpenAI official model page, observed 2026-09-25. · [context source](https://developers.openai.com/api/docs/models/gpt-5.5-pro): OpenAI model page for gpt-5.5-pro: 1,050,000 context window, 128,000 max output tokens. Observed 2026-09-25. [interactive version](https://whatmodel.sh/model/gpt-5-5-pro) · [JSON](https://whatmodel.sh/api?format=json&all=1)