AI Model Overview

OpenAI GPT-5.5 — what it is, when to use it and what to use instead

Active

No. GPT-5.5 is active at OpenAI and has no announced end date.

gpt-5.5 last verified

Summary

GPT-5.5 is the previous flagship in OpenAI's GPT-5 line, at $5 per million input tokens and $30 per million output tokens with a 1.05M-token context window and 128K max output. GPT-5.6 Sol is both newer and cheaper at $4 / $20.

GPT-5.5 was positioned for coding and professional work and still runs on the default snapshot gpt-5.5-2026-04-23. It has been overtaken by the GPT-5.6 line on both price and knowledge cutoff: Sol costs $4 / $20 with a February 2026 cutoff, against $5 / $30 and 1 December 2025 here.

It accepts text and image input and returns text, with reasoning effort from none to xhigh, structured outputs, function calling and the full tool set including computer use and MCP. Prompts above 272K input tokens are charged at a premium rate.

No deprecation has been announced.

Modality
  • Text
  • Vision
Use case
  • Chat
  • Coding
  • Reasoning
  • Agents & tool use
  • Long context
  • Web search
Tier
  • Mid-tier
Access
  • Hosted API

Specifications

Input price
$5.00 / M tokens
Output price
$30.00 / M tokens
Price band
Premium
Context window
1.1M tokens
Max output
128K tokens
Input
Text, image
Output
Text
Knowledge cutoff
December 2025
Tool use
Yes
Structured output
Yes
Weights licence
not published
Model maker
OpenAI

“unknown” means the figure has not been published, or we have not verified it yet — never that the answer is no. “not published” under the weights licence means this model is not offered with downloadable weights. The price band is ours: it bands the blended price (three parts input to one part output) as budget (≤ $0.50), standard (≤ $3), premium (≤ $12) or flagship.

Lifecycle

OpenAI has not announced a deprecation or shutdown date for this model. That is a statement about what has been published, not a guarantee — providers typically announce a shutdown months ahead, and this page updates when they do.

  1. Released
  2. Deprecated not announced
  3. Retired not announced

Use it for

  • Keep an existing GPT-5.5 integration running while you evaluate GPT-5.6 Sol against it.
  • Stay on a pinned snapshot where output has to remain comparable across releases.

Avoid it when

  • You are starting a new integration; GPT-5.6 Sol is cheaper at $4 / $20 and has a newer February 2026 knowledge cutoff.
  • Your prompts routinely exceed 272K input tokens, where premium pricing applies.
  • Cost per call is a constraint; GPT-5.6 Terra offers the same limits at $2 / $12.

Alternatives to consider

  • GPT-5.6 Sol Curated

    OpenAI Active

    Newer and cheaper at $4 / $20 against $5 / $30, with the same 1.05M-token window and a February 2026 cutoff.

    $4.00 in · $20.00 out / M tokens 1.1M context

  • GPT-5.5 Pro Curated

    OpenAI Active

    The high-compute variant of the same generation at $30 / $180, when one better answer is worth minutes of latency.

    $30.00 in · $180.00 out / M tokens 1.1M context

  • Claude Opus 5 Curated

    Anthropic Active

    Anthropic's top general tier at $5 / $25 with a 1M-token window and a May 2026 knowledge cutoff.

    $5.00 in · $25.00 out / M tokens 1M context

  • Gemini 3.1 Pro Preview Curated

    Google (Gemini) Active

    Google's Pro-series preview at $2 / $12, with audio, video and PDF input that GPT-5.5 does not accept.

    $2.00 in · $12.00 out / M tokens 1M context

  • GPT-5 Derived

    Microsoft Azure AI Foundry Active

    Alternative from Microsoft Azure AI Foundry, same tier (mid-tier), similar price; shares chat, coding, reasoning, agents, long-context and search.

    $1.25 in · $10.00 out / M tokens 400K context

Curated suggestions were picked by a reviewer, with the reason written by hand. Derived suggestions are ranked from the data — shared tags, the same tier and a comparable price band — not from benchmark scores. Check the capability fit yourself: we track lifecycle, price and specifications.

Sources

Verified against the source on . Dataset snapshot . Providers can change a date without notice — the link above is always the final word.

About this profile

The specifications and dates above are facts from OpenAI, with the sources listed. The summary, the use-for and avoid-when lists and the curated alternatives are our assessment: editorial profile reviewed on by llm-researcher.

Common questions

What is GPT-5.5 for?
GPT-5.5 is the previous flagship in OpenAI's GPT-5 line, at $5 per million input tokens and $30 per million output tokens with a 1.05M-token context window and 128K max output. GPT-5.6 Sol is both newer and cheaper at $4 / $20.
What does GPT-5.5 cost?
$5.00 per million input tokens and $30.00 per million output tokens, as last verified on 2026-09-10.
What is the context window of GPT-5.5?
1.1M tokens.
Is GPT-5.5 deprecated?
No. GPT-5.5 is active at OpenAI and has no announced end date.
What should I use instead of GPT-5.5?
OpenAI GPT-5.6 Sol — Newer and cheaper at $4 / $20 against $5 / $30, with the same 1.05M-token window and a February 2026 cutoff. OpenAI GPT-5.5 Pro — The high-compute variant of the same generation at $30 / $180, when one better answer is worth minutes of latency. Anthropic Claude Opus 5 — Anthropic's top general tier at $5 / $25 with a 1M-token window and a May 2026 knowledge cutoff.

All OpenAI models and their end dates →