File type / text
.htm
Human-readable text or code. Easy to inspect and version-control.
Best for: Source code, configuration files, logs, and documentation that should stay transparent to collaborators.
Type family
text
Subtype
html
Default handling
Inline-capable
Handling verdict
Modern browsers can usually display this media type without downloading it first.
The media type is text-like, but this record does not declare a charset.
HTTP content encoding can usually reduce this format further.
Text files rarely carry threats, but scripts can execute commands. Review before running.
HTTP response headers
Content-Type: text/html
Content-Disposition: inline; filename="example.htm"
X-Content-Type-Options: nosniffThe MIME type describes the payload, Content-Disposition controls whether the browser previews or saves it, and nosniff prevents the browser from silently substituting a guessed type.
HTML file input
accept=".htm,.html,.shtml,text/html"Use this value on <input type="file"> to steer the picker toward .htm, its known aliases, and files reporting text/html. It improves selection, but it is not validation—check the bytes again after upload.
Registry ledger
declared valuesMIME type
text/html
Registry source
iana
Character set
Not declared
Compressible
Yes
Known aliases
.html, .shtml
Same MIME type
.html
How to work with .htm
operational notesOpen it with the format-aware tool first
Start with VS Code, Sublime Text, Any plain-text viewer. Normalize line endings and explicit UTF encodings when sharing across operating systems. If the file came from someone else, keep the original untouched and work on a copy so a failed conversion cannot destroy the only source.
Safety note
Text files rarely carry threats, but scripts can execute commands. Review before running.