Models · OpenAI · Out sinceReleased 23 Apr 2026

GPT-5.5 Pro

Available on OpenRouterOn OpenRouterAvailable nowGenerally availableClosed (can't be downloaded)Proprietary

GPT-5.5 Pro is made by OpenAI. We don't have enough test results yet to rank it. It's expensive to use.

Separate Pro model id (more compute per request); default effort high; no cached-input discount.

Writing & creativity: —
Research & analysis: —
Coding: —
Price: Expensive$30 / $180
Price per 1M (blended)Blended / 1M: $67.50
MemoryContext: 1.1M
Longest answerMax output: 128K
Test resultsResults: 11 (5 independent5 indep.)
Out sinceReleased: 23 Apr 2026
Made byVendor: OpenAI
UnderstandsInputs: text, image

Scores are out of 100 for each area, compared with every model we track; “#” is its rank. Context is how much text it can read at once (1M is roughly 700,000 words). Blended price mixes the cost of what you send and what it writes back.

Thinking levels

Reasoning settings

MediumHighExtra high

Links

Using it through OpenRouter

On OpenRouter

OpenRouter is a service that gives access to many AI models in one place. This model is listed there as openai/gpt-5.5-pro.

Route it as openai/gpt-5.5-pro at $30 in / $180 out per 1M tokens, 1.1M context. Listed since 24 Apr 2026.

include_reasoningmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools

Every test result

Every result

All the numbers,with where they came from.

Every result we've found for this model, with who measured it and a link to where we read it.

All raw rows (vendor and independent kept separate), with setting label, source, date, harness and notes.

All results for this model
						NotesNotes
BrowseComp	90.1%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—
Epoch Capabilities Index	162.4	Default	Independent testIndependentEpoch AI ↗	1 Oct 2026	—	Epoch Capabilities Index; 90% CI 159.0-166.0; best of listed model versions
FrontierMath (Tiers 1-3)	87.7%	Extra highgpt-5.5-pro_xhigh	Independent testIndependentEpoch AI ↗	12 Jun 2026	—	FrontierMath Tiers 1-3 (v2), Epoch-run; stderr 1.9pt; data https://epoch.ai/data/benchmark_data.zip (frontiermath_tiers_1_3_v2.csv)
FrontierMath Tier 1-3	52.4%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—
FrontierMath Tier 4	78.0%	Extra highgpt-5.5-pro_xhigh	Independent testIndependentEpoch AI ↗	12 Jun 2026	—	FrontierMath Tier 4 (v2), Epoch-run; stderr 6.5pt; data https://epoch.ai/data/benchmark_data.zip (frontiermath_tier_4_v2.csv)
FrontierMath Tier 4	39.6%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—
GDPval	82.3%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—	wins or ties
GPQA Diamond	93.9%	Extra highgpt-5.5-pro-pre-release_xhigh	Independent testIndependentEpoch AI ↗	24 Apr 2026	—	Epoch-run GPQA Diamond; stderr 1.6pt; data https://epoch.ai/data/benchmark_data.zip (gpqa_diamond.csv); pre-release checkpoint
Humanity's Last Exam	43.1%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—	no tools
Humanity's Last Exam (with tools)	57.2%	Extra highGPT-5.5 Pro, reasoning effort=xhigh	Maker's own figureVendor-reportedOpenAI ↗	23 Apr 2026	—
SimpleBench	76.9%	DefaultGPT-5.5 Pro	Independent testIndependentSimpleBench ↗	24 Apr 2026	—	AVG@5, temp 0.7; rank 10th; human baseline 83.7%; data https://simple-bench.com/static/js/leaderboard-data.js