All tools
Extension repair
Fix incorrect file extensions
Extension fixing helps when files cannot be opened because the suffix no longer matches the actual file type. It is especially useful for downloaded archives and renamed compressed files.
Best for
Use this when archives or downloaded files have wrong suffixes and need their real extension restored.
Rename examples
Fix ZIP suffix
important.zip111
important.zip
Fix RAR suffix
backup.rar001
backup.rar
Restore archive type
archive.7z.tmp
archive.7z
Common use cases
- Repair archive extensions after downloads or transfers.
- Identify disguised archives by reading file signatures.
- Batch fix files before extraction or handoff.
How to use it
- 1Add files with suspicious extensions.
- 2Choose the extension fix rule and keep archive-only mode when appropriate.
- 3Preview detected extensions before applying.
Limits and checks
- Use extension fixes when the content type is known or the extension is visibly wrong.
- Changing an extension does not convert the file format.
- Preview mixed folders carefully because extension changes affect how apps open files.
Common mistakes to avoid
- Renaming .png to .jpg and expecting image data to be converted.
- Changing extensions in a mixed folder without filtering file types first.
- Forgetting that hidden or double extensions can hide the real suffix.
FAQ
Does this change file contents?
No. The rule reads file headers to infer type, then changes the file name extension only.
Why is archive-only mode recommended?
Archive signatures are usually clearer than many other file types, so archive repair is the safer default.