# GPT-5.5-Pro

GPT-5.5-Pro is an AI model released by OpenAI on Apr 23 2026. Tracked results include 52.4% on FrontierMath (Tier 1–3), 39.6% on FrontierMath (Tier 4) and 36% on BullshitBench v2.

## Facts

| Field | Value |
| --- | --- |
| Model | GPT-5.5-Pro |
| Developer | OpenAI |
| Release date | Thursday, Apr 23 2026 |
| Licensing | Proprietary |

## API pricing

All rates in USD per 1,000,000 tokens, pay-as-you-go.

| Tier | Input | Output |
| --- | --- | --- |
| All documented contexts | $30.00 | $180.00 |

Verified August 18, 2026 against the first-party source: https://developers.openai.com/api/docs/models/gpt-5.5-pro

## Tracked benchmark scores

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 36% | [BullshitBench](https://github.com/petergpt/bullshit-benchmark) | Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. |
| Next.js Evals | 65% | [Next.js Evals](https://nextjs.org/evals) | Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. |
| BrowseComp | 90.1% | Lab | Can the AI browse the web and track down hard-to-find answers? Higher is better. |
| Humanity's Last Exam (with tools) | 57.2% | [BenchLM](https://benchlm.ai), retrieved 2026-07-11 | Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. |
| FrontierMath (Tier 1–3) | 52.4% | Lab | Very hard, research-level math problems. Tiers 1–3 are the (still extremely difficult) lower tiers. Higher is better. |
| FrontierMath (Tier 4) | 39.6% | Lab | Very hard, research-level math problems. Tier 4 is the hardest — close to what professional research mathematicians tackle. Higher is better. |
| GDPval (win/tie rate) | 82.3% | Lab | How often the AI's work matches or beats a human expert's on real knowledge-work tasks. Higher is better. |

## Questions and answers

### When was GPT-5.5-Pro released?

GPT-5.5-Pro was released by OpenAI on Thursday, Apr 23 2026.

### Who made GPT-5.5-Pro?

GPT-5.5-Pro was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

### How much does GPT-5.5-Pro cost?

GPT-5.5-Pro costs $30.00 per million input tokens and $180.00 per million output tokens through the OpenAI API. Rates are pay-as-you-go API prices verified against OpenAI's published pricing on August 18, 2026.

### What benchmark scores did GPT-5.5-Pro get?

GPT-5.5-Pro reports 7 tracked benchmark scores — BullshitBench v2: 36%; Next.js Evals: 65%; BrowseComp: 90.1%; Humanity's Last Exam (with tools): 57.2%; FrontierMath (Tier 1–3): 52.4%; FrontierMath (Tier 4): 39.6%; GDPval (win/tie rate): 82.3%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data. It holds the best score among all models tracked here on FrontierMath (Tier 1–3) and FrontierMath (Tier 4).

### Is GPT-5.5-Pro open source?

No. GPT-5.5-Pro is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after GPT-5.5-Pro?

OpenAI's previous tracked release was GPT-5.5 on Apr 23 2026. It was followed by GPT-5.5-Cyber on Jun 22 2026.


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Canonical page: https://aireleasetracker.com/model/openai/gpt-5.5-pro
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.