.tmp

What is a .tmp file?

A scratch file created during processing — safe to delete when the app isn't running.

Safe format
Type Misc
By N/A (convention)
MIME application/octet-stream

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What is it

TMP is a generic extension for temporary files — scratch data that applications create while processing, installing, or updating. Every time you edit a Word document, install software, or extract an archive, the operating system and applications create .tmp files in your temp directory. They're the digital equivalent of scratch paper.

There's no standard format for .tmp files. They might contain partially written documents, decompressed installation data, cached database queries, print spool data, or intermediate computation results. Windows stores them in `%TEMP%` (usually `C:\Users\YourName\AppData\Local\Temp`), macOS uses `/tmp` or `/var/folders/`, and Linux uses `/tmp` or `/var/tmp`.

TMP files should be cleaned up automatically by the applications that create them — but they often aren't, especially after crashes or forced shutdowns. Over time, the temp directory accumulates gigabytes of orphaned .tmp files. It's generally safe to delete them when no applications are running, and both Windows (Disk Cleanup) and macOS (periodic system maintenance) include automated temp file cleanup.

Technical details
Full Name
Temporary File
MIME Type
application/octet-stream
Developer
N/A (convention)
Magic Bytes
Varies
Safety
.tmp is a known, safe format.
What opens it
Depends on content
FREE All
Any text editor
FREE All

* For text-based temp files

FAQ
Can I delete .tmp files?
Yes, if the application that created them isn't running. Close all programs first, then clean your temp folder. Windows: run Disk Cleanup or delete contents of %TEMP%. macOS/Linux: /tmp is usually cleaned on reboot.
Why do I have so many .tmp files?
Applications create them during normal operation and should delete them when done. After crashes, forced shutdowns, or incomplete installations, orphaned .tmp files accumulate. Regular cleanup is recommended.
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