Grok 4.20 Reasoning

xAI · March 2026

An earlier Grok that thinks before answering, so it is slower.

Superseded by Grok 4.3 →

  • Modalities

  • Context window

    1,000,000 tokens, ≈ 750,000 words · about 3,000 pages

Providers

Files you can attach

  • ImagesJPG, PNG
  • DocumentsNot supported
  • 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
  • Image generationSupported
  • Code interpreterSupported
  • Hosted shellSupported
  • Apply patchNot supported
  • SkillsNot supported
  • Computer useNot supported
  • Tool searchNot supported

Features

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

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