whatfileis.pro

Paste a filename and find out what it is, whether it is safe, and what opens it.

.tmp vs .temp: Are They the Same?

Both extensions mean 'temporary', and in practice they behave the same way — throwaway data an app wrote mid-task. The difference is mostly which program picked which spelling.

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Safe to delete?

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Short answer: both mean a temporary file, and neither is a real format on its own — the extension is just a label. .tmp is the near-universal choice (Windows, Office, installers, browsers). .temp is the same idea, used by a smaller set of apps and scripts. There is no technical rule that makes .temp different from .tmp; the contents depend entirely on the program that wrote it.

Who makes them

.tmp — Windows, Microsoft Office (e.g. ~$doc.tmp), installers, and countless apps that need scratch space.
.temp — some backup tools, custom scripts, and apps that simply spelled it out. Less common, same purpose.

Are they safe to delete?

Usually yes, when the program that made them is closed. A .tmp or .temp locked by a running app should not be forced — quit the app first and it often cleans up itself. Never assume the contents: a .tmp can be leftover junk or a mid-save copy of real work, so don't delete one belonging to a document you have open.

How to find and clear temp files safely

Close the apps first. A .tmp or .temp held by a running program may be live scratch data. Quit Office, installers and browsers before cleaning.
Windows: press Win+R, type %temp%, delete what the system lets you (locked files are skipped automatically). Or run cleanmgr (Disk Cleanup) and tick Temporary files.
macOS / Linux: user temp files live under /tmp and $TMPDIR; the OS clears these on reboot, so a manual sweep is rarely needed.

When a .tmp is actually your work

Office writes an unsaved document to a ~$-prefixed .tmp while you edit. If Word or Excel crashed, that .tmp can hold the only copy of your last edits — rename it to .docx/.xlsx and open it before deleting anything. Treat any .tmp next to a document you had open as potential recovery data, not junk.

FAQ

Is .temp just a misspelling of .tmp?

Not a misspelling — both are valid 'temporary file' labels. .tmp is the common one; .temp is the same idea used by fewer programs. Neither is a fixed format.

Can I open a .tmp or .temp file?

You can try a text or hex editor to see what is inside, but the contents depend on the app that made it. Many are unreadable scratch data and are meant to be discarded.

Is it safe to delete .tmp and .temp files?

Generally yes once the creating program is closed. Don't delete one that a running app has locked, and don't delete a .tmp tied to a document you currently have open.

Why do programs create a .tmp instead of saving directly?

A program writes to a .tmp first so that a crash mid-save can't corrupt your original file. On a successful save it renames the .tmp over the real file. That's why you sometimes see a leftover .tmp when an app closed badly.

Can I turn a .tmp file back into its original format?

Only if you know which program made it. Rename the extension to the one you expect (e.g. .docx, .xlsx) and try opening it. If the .tmp was an incomplete write it may not open — it was never a finished file.

Where does Windows keep .tmp and .temp files?

Mostly in %TEMP% (C:\Users\<you>\AppData\Local\Temp) and in each program's own working folder. Disk Cleanup and Storage Sense clear these safely when the app that made them is closed.

How do I open a .tmp file to see what's inside?

Make a copy first, then try opening the copy in a text editor — many .tmp files are plain text or XML and will reveal their origin. If it's a crashed Office file (name starts with ~$), rename the copy to .docx or .xlsx and open it in Word/Excel. Binary .tmp files that show gibberish are app scratch data and safe to ignore.

Other file types explained