Models

GPT-5.1 Chat

OpenAI · November 2025

The build that ran ChatGPT for GPT-5.1. Tuned for conversation, with a short thinking step.

Superseded by GPT-5.2 Chat →

  • Modalities

  • Context window

    128,000 tokens, ≈ 96,000 words · about 380 pages

  • Max output

    16,384 tokens, ≈ 12,000 words in a single answer

  • Knowledge cutoff

    September 2024

Reasoning effort

  • Low

  • Medium

  • 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

Features

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

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