h2non/filetype

Health v2 · maintenance only

Adoption not part of the score

2297 stars · 190 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

A small, dependency-free Go library that infers file and MIME types by checking binary magic number signatures. It supports a wide range of file types, requires only the first 262 bytes of a file, and allows pluggable custom matchers.

Use cases

• detect the real file type of an uploaded file regardless of its extension
• get the MIME type from a binary file header in Go
• check if a file is an image, video, or audio by its content
• validate that uploaded files match their claimed extension
• identify file types from just the first bytes of a stream

When to choose

• you need fast, dependency-free file type detection in Go
• you only have access to a file header or byte slice, not the full file
• you want to validate uploads by content rather than trusting extensions or client-supplied MIME types

When to avoid

• you need to detect text-based formats like SVG (use go-is-svg instead)
• you need deep content inspection beyond the file header
• you are not working in Go

Facets

library · maturity stable

parser developer-tools files developer-tools go cross-platform magic-numbers mime-type file-type-detection file-validation

Member repositories

For agents

markdown · JSON · MCP: product_card(name="h2non/filetype")