OpenAI · llm model
GPT-5.5 Pro
GPT-5.5 Pro is an OpenAI language model released Apr 24, 2026; OpenAI's newest language model in our dataset is GPT-6.1 Terra. Proprietary, API access only. OpenAI's GPT-5.5 Pro, released Apr 24, 2026 for harder problems; it uses more compute and has no cached-input discount. Verified against vendor sources on Oct 26, 2026.
Reported Last verified · All models · JSON · Markdown
- ReleasedApr 24, 2026
- Context window1.05M1,050,000 tokens
- Max output128K128,000 tokens
- LicenceProprietaryProprietary (API)
InTextImageOutText
Key facts
| Fact | Value | Source |
|---|---|---|
| Vendor | OpenAI | n/a |
| Released | Apr 24, 2026 | source |
| Status | generally available | n/a |
| API id | gpt-5.5-pro | source |
| Context window | 1,050,000 tokens (1.05M) | source |
| Max output | 128,000 tokens | source |
| Input | text, image | source |
| Output | text | source |
| Licence | Proprietary (API) | source |
| Pricing | $30 in / $180 out per 1M tokens | source |
Where GPT-5.5 Pro sits in our data
- Released Apr 24, 2026 (week 17 of 2026), in April 2026. Other models in our data released that month: Mistral Medium 3.5, GPT-5.5, Qwen3.6-27B, GPT-Image-2, Claude Opus 4.7, GLM-5.1.
- The previous OpenAI model we track is GPT-Image-2 (Apr 21, 2026), 3 days earlier.
- Of the 60 models in our data with a published context window, GPT-5.5 Pro has the number 9 largest (1.05M tokens). Our data is not every model on the market.
- OpenAI tools we cover: Codex CLI, ChatGPT, OpenAI Agents SDK.
- All releases by date: AI model releases by month · new AI models this week. Choosing for code: best LLM for coding.
How GPT-5.5 Pro differs from GPT-5.5
Read from the recorded facts of the two models, not from a head-to-head test. We have not run either.
- Listed price is $30 in and $180 out, against $5 in and $30 out for GPT-5.5 (per 1M tokens).
- Both list a 1.05M-token context window.
- Both accept text, image as input.
- Both were released on Apr 24, 2026.
- Facts for the other model: GPT-5.5.
What we tested
Nothing yet. We have not run GPT-5.5 Pro ourselves, so every fact on this page is Reported from the sources below. When we do test it, the scope will be stated here and in our test logs. See methodology.
Sources
More from OpenAI
- GPT-5.5 (Apr 24, 2026)
- GPT-Image-2 (Apr 21, 2026)
- GPT-5.4 mini (Mar 17, 2026)
- GPT-5.4 (Mar 5, 2026)
- GPT-Realtime-2.1 (Jul 6, 2026)
- GPT-Realtime-2.1 mini (Jul 6, 2026)
- GPT-5.6 Luna (Jul 9, 2026)