Is it safe to delete .tmp files?

Generally yes. Use Disk Cleanup or Storage Sense rather than deleting by hand, and close any running programs first, since a .tmp in active use belongs to something that is still working with it.

Can I recover a Word document from a .tmp file?

Sometimes. Copy the file, rename the copy to .docx and try opening it. First though, use Word's File, Info, Manage Document, Recover Unsaved Documents, which is the supported route and usually works better.

File extensions

How to open a .tmp file

Temporary file · Ambiguous / system

A .tmp file is scratch data a program left behind, and the contents depend entirely on which program made it. Most are safe to delete. The exception worth knowing is a Word or Excel temp file that may hold unsaved work.

What a .tmp file actually is

Programs write .tmp files while working and normally delete them on exit. The ones you find have survived a crash, a forced shutdown or sloppy cleanup.

There is no .tmp format. Some contain plain text, some are a partial copy of a document, some are meaningless once the program has gone.

Why it will not open

Nothing opens it because the extension describes a purpose, not a format. People usually arrive here for one of two reasons: they want to recover a lost document, or they want to know whether it is safe to delete a folder full of them.

Step by step

Windows

01If you are recovering lost work: look in %TEMP% and in the document's own folder for files starting with ~$ or ending in .tmp with a recent timestamp.
02Copy the candidate somewhere safe, rename the copy to .docx or .xlsx, and try opening it. Word and Excel temp files are often the real document under a different name.
03Better first: open Word and check File, Info, Manage Document, Recover Unsaved Documents. That is the supported route and it works more often.
04If you just want to clean up: Disk Cleanup or Storage Sense removes temporary files safely. Deleting a .tmp belonging to a running program is the only real risk, and closing the program first avoids it.
05To identify an unknown one, open it in HxD and read the header.

macOS

01Temporary files live in /tmp and in per-user folders under /var/folders, and macOS clears them on restart.
02Run "file yourfile.tmp" in Terminal to see what it actually is.

What usually goes wrong

Rename a copy, never the original

If a .tmp really is your unsaved document, it is the only copy. Work on a duplicate so a failed rename or a program that overwrites it does not cost you the file.

Programs that open .tmp

Our pick, in order. Every one links to the publisher's official download URL and the SHA-256 hash of the installer, so you can check the file before you run it.

HxD Hex EditorHex and Disk Editorv2.5 · 1 hashed installer85

Common questions

Is it safe to delete .tmp files?: Generally yes. Use Disk Cleanup or Storage Sense rather than deleting by hand, and close any running programs first, since a .tmp in active use belongs to something that is still working with it.
Can I recover a Word document from a .tmp file?: Sometimes. Copy the file, rename the copy to .docx and try opening it. First though, use Word's File, Info, Manage Document, Recover Unsaved Documents, which is the supported route and usually works better.