sindresorhus/file-type

Health v2 · maintenance only

Adoption not part of the score

4321 stars · 394 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

A Node.js/JavaScript library that detects the file type of a file, stream, or buffer by checking its magic number (binary signature). It returns the detected extension and MIME type for binary-based file formats.

Use cases

• detect file type from uploaded file in nodejs
• get mime type from a buffer or uint8array
• identify file extension from a stream
• validate uploaded file type by magic numbers
• detect image or video format from file header bytes
• sniff file type of a fetched remote resource

When to choose

• you need to detect binary file formats in Node.js from files, streams, or buffers
• you want a lightweight, well-maintained ESM package for MIME/extension sniffing
• you need to validate uploads by their actual binary signature rather than filename

When to avoid

• you need to detect text-based formats like .txt, .csv, or .svg
• you need guaranteed validation that a file is well-formed and not malformed
• your project is CommonJS-only and cannot consume ESM packages

Facets

library · maturity stable

parser developer-tools file-system developer-tools files web-development magic-numbers file-type-detection mime-type uint8array esm nodejs javascript

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markdown · JSON · MCP: product_card(name="sindresorhus/file-type")