GPT-5.5: Specs, Pricing & Best Use Cases

GPT-5.5 is OpenAI's newest frontier model, built for complex professional work like coding, research, and multi-step agentic tasks. Released April 23, 2026 as the successor to GPT-5.2 and GPT-5.4, it brings a 1M+ token context window, stronger reasoning, and API pricing of $5 per million input tokens and $30 per million output tokens. This guide breaks down its specs, pricing, benchmarks, and the use cases where it's actually worth the premium.

GPT-5.5 is a large language model from OpenAI designed for real-world professional work: writing and debugging code, researching online, analyzing data, and creating documents and spreadsheets. Compared to earlier models, it understands a task earlier in the conversation, needs less hand-holding, and uses external tools more reliably to reach a finished result.

OpenAI released GPT-5.5 alongside two variants: GPT-5.5 Thinking for deeper reasoning and GPT-5.5 Pro, which uses extra test-time compute for the hardest problems. A separate release, GPT-5.5 Instant, updated the default model in ChatGPT with better factual accuracy and less verbose answers. API access opened the following day, on April 24, 2026.

GPT-5.5 reaches high-quality answers with fewer tokens and fewer retries than its predecessors. It scored 82.7% on Terminal-Bench 2.0 and posted strong results on FrontierMath, a difficult math reasoning benchmark, outperforming rival models like Claude Sonnet 5 and Gemini on the same tasks in OpenAI's own testing.

The model supports a context window over one million tokens (roughly 922K input and 128K output), with both text and image inputs. That headroom matters for large codebases, long documents, and workflows that move across many tools in a single session.

Bigger, more capable models are usually slower to run, but GPT-5.5 matches GPT-5.4's per-token serving speed while performing at a noticeably higher level. On coding-focused benchmarks, OpenAI reports it delivers competitive intelligence at roughly half the cost of other frontier coding models.

GPT-5.5 costs twice as much as GPT-5.4 per token, but it's better at generating documents, spreadsheets, and presentations, and pairs well with computer-use skills that let it see a screen and navigate interfaces directly. Older models like GPT-5 remain useful for simpler, lower-cost tasks, while GPT-5.5 targets the harder end of professional work.

GPT-5.5 is priced and built for demanding work, not high-volume cheap tasks. It earns its cost in these scenarios:

• Complex software engineering. Multi-file refactors, large codebases, and agentic coding sessions benefit from the 1M+ context window and lower retry rate.
• Deep research and document synthesis. Pulling insights from many long sources at once works well with the larger context window. Pair it with an AI article summarizer for faster first passes.
• Agentic and computer-use workflows. Tasks that involve seeing a screen, clicking, and navigating across tools benefit from GPT-5.5's improved tool-use reliability.
• Business documents and spreadsheets. Turning messy inputs into structured plans, reports, or spreadsheet models is an area where GPT-5.5 outperforms GPT-5.4.
• Advanced technical and math reasoning. FrontierMath-level problems and multi-step scientific reasoning are where the reasoning gains show up most clearly.
• High-stakes writing. The GPT-5.5 Instant variant reduces hallucinated claims significantly, which matters for medical, legal, and financial content.

GPT-5.5 itself isn't available on Chat Smith. The platform has since moved on to newer models, including GPT-5.6 Sol, alongside Claude Sonnet 5 and Gemini, all in a single interface.

• Compare GPT-5.6 Sol's answers side by side with models such as Gemini 2.5 Pro or Grok 4.5
• Use the current flagship for coding, long-document analysis, or drafting business documents in one chat
• Switch models mid-conversation without losing your chat history

GPT-5.5 pushes OpenAI's model lineup further into agentic, professional-grade work, with a bigger context window, stronger reasoning, and no drop in speed — at roughly double GPT-5.4's price. For coding, research, and high-stakes writing, that premium is usually worth it. For simpler, high-volume tasks, a smaller model will do the job for less.