Skip to content

What is an HTML file?

HTML is the file a web page is made of. Any browser opens one directly, which makes it a handy way to hand someone a formatted document without needing an office program at either end. You can convert HTML files here, both into the format and out of it.

Specification

HTML format specifications
Full nameHyperText Markup Language
Extensions.html, .htm
Media typetext/html
CompressionUncompressed
Transparency
Animation
Multiple pagesNot supported
Colour depthUTF-8 markup rendered through the CSS box model
Size limits
Introduced1993
Developed byTim Berners-Lee, now WHATWG
StandardOpen
Browser supportEvery browser, including older ones

What HTML is used for

  • Web pages and web application interfaces
  • HTML email templates rendered inside mail clients
  • Exported reports and dashboards meant to be opened in a browser
  • An intermediate format when moving content between document tools

Strengths and limitations

What HTML does well

  • Renders in every browser with no plugin, viewer or conversion
  • Reflows to any screen size, which fixed-layout formats cannot do
  • Text is semantic and machine readable, so search and accessibility work well

Where HTML falls short

  • Appearance depends on CSS, fonts and the browser, so it is not fixed layout
  • A single file often references external images, styles and scripts
  • Printing and pagination are unreliable compared with PDF

Convert HTML to

Every target this format can be written out as, each on its own page.

Convert to HTML

Everything that can be turned into a HTML file.

Questions about HTML

What is a .html file?

HTML is the file a web page is made of. The extension .html or .htm identifies it, and its media type is text/html.

How do I open an HTML file?

Any current browser will open it directly, so dragging the file into a tab is usually enough. Most operating systems also preview it without extra software.

Is HTML lossy or lossless?

Uncompressed. Nothing is discarded, so repeated saves never degrade the contents.

What is HTML good for?

Renders in every browser with no plugin, viewer or conversion. Reflows to any screen size, which fixed-layout formats cannot do. Text is semantic and machine readable, so search and accessibility work well. In practice that makes it a good fit for web pages and web application interfaces, and HTML email templates rendered inside mail clients.

What are the drawbacks of HTML?

Appearance depends on CSS, fonts and the browser, so it is not fixed layout. A single file often references external images, styles and scripts. Printing and pagination are unreliable compared with PDF.

Other document formats

Documents converter or the full format reference