OpenAI Releases GPT-5.5: Faster, Smarter, More Expensive

OpenAI has released GPT-5.5, calling it “a new class of intelligence for real work.” The model, which launched on April 23 alongside a more powerful GPT-5.5 Pro variant, is now available in ChatGPT and the API for paid subscribers. It arrives just weeks after GPT-5.4 and in the same week that DeepSeek released its V4 models — a sign of how fast the AI race is moving.

What’s New

GPT-5.5 is built for multi-step, real-world tasks. OpenAI says it understands what you’re trying to do faster, asks for less guidance, uses tools more effectively, and keeps working until the job is done. It’s particularly strong at writing and debugging code, researching online, analysing data, creating documents, and operating software.

The model also powers Codex, OpenAI’s agentic coding tool, and forms the backbone of the new OpenAI Frontier enterprise platform for building and managing AI agents.

How It Performs

GPT-5.5 tops the Artificial Analysis Intelligence Index at 60 points, three ahead of both Claude Opus 4.7 and Gemini 3.1 Pro. Its standout results are in tool use and agentic tasks — it scores 82.7% on Terminal-Bench 2.0, well ahead of Claude (69.4%) and Gemini (68.5%). On FrontierMath Tier 4, GPT-5.5 Pro scored 39.6%, nearly double Claude’s 22.9%.

It’s not the best at everything, though. Claude Opus 4.7 still leads on software engineering benchmarks like SWE-bench Pro (64.3% vs 58.6%) and scores higher on Humanity’s Last Exam (46.9% vs 41.4%). One notable weakness: independent testing found GPT-5.5 still hallucinates more frequently than its competitors.

What It Costs

The API price has roughly doubled from GPT-5.4: $5 per million input tokens and $30 per million output tokens. GPT-5.5 Pro costs $30 input and $180 output per million tokens. OpenAI argues the effective increase is closer to 20% because GPT-5.5 is more token-efficient — it gets more done with fewer tokens.

For ChatGPT users, nothing changes on the subscription side. Plus ($20/month) gives you GPT-5.5, while Pro ($200/month) unlocks GPT-5.5 Pro. Free-tier users don’t have access yet.

What This Means for You

If you’re already paying for ChatGPT Plus, you get a meaningful upgrade at no extra cost. The model is noticeably better at complex tasks that involve multiple steps — like researching a topic, pulling data, and writing a report. Coders using Codex should see real improvements in how the AI handles larger projects.

If you use the API, the price increase is significant. Developers building cost-sensitive applications may want to weigh GPT-5.5 against DeepSeek V4, which offers near-frontier performance at a fraction of the price.

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