Models

GPT-5.5

OpenAI · April 2026

A capable all-rounder: conversation, code, hard problems and multi-step work.

Superseded by GPT-5.6 Sol →

  • Modalities

  • Context window

    1,050,000 tokens, ≈ 788,000 words · about 3,150 pages

  • Max output

    128,000 tokens, ≈ 96,000 words in a single answer

  • Knowledge cutoff

    December 2025

Reasoning effort

Default: Medium

  • None

  • Low

  • Medium

  • High

  • X-High

Providers

Files you can attach

  • ImagesJPG, PNG, GIF, WEBP
  • DocumentsPDF, DOCX, XLSX, PPTX
  • Text and codeTXT, MD, CSV, TSV, RPT, LOG, PY, TS, TSX, JS, JSX, CS, GO, JAVA, KT, SWIFT, CPP, C, H, PHP, RB, SQL, SH, PS1, HTML, CSS, SCSS, JSON, YAML, YML, XML, INI

Tools

  • Web searchSupported
  • File searchSupported
  • Image generationSupported
  • Code interpreterSupported
  • Hosted shellSupported
  • Apply patchSupported
  • SkillsSupported
  • Computer useSupported
  • MCPSupported
  • Tool searchSupported

Features

  • StreamingSupported
  • Function callingSupported
  • Structured outputsSupported
  • Fine-tuningNot supported

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