HTML file format

HyperText Markup Language, the structure format of web pages.

MIME type: text/html
Extensions: .html, .htm
Category: Text & markup

Magic-number signature

Plain text starting with '<!doctype html' or '<html'.

About the HTML format

HTML is the markup language of the web, describing document structure that browsers render. It is identified by a leading '<!doctype html' or '<html' near the top of the file rather than any byte signature.

Related formats

XML
JSON
SVG

Have a file that might be HTML? Identify it with the File Type Identifier — it reads the magic number locally, nothing is uploaded. Or browse all formats.