ACE
Also known as: ACE file, .ace archive, WinAce
ACE is a proprietary compressed archive format, created with WinAce, that once offered high compression ratios. It is now obsolete and has been flagged for serious security vulnerabilities, so opening .ace files is discouraged.
- Proprietary high-ratio archive from WinAce
- Obsolete and flagged for security vulnerabilities
- Best converted to ZIP or 7z if trusted
A once-popular high-ratio archiver
ACE competed with RAR and ZIP by aiming for tighter compression, and was created with the WinAce tool. For a time it was a favorite for squeezing large downloads into smaller archives.
Development stopped years ago, and the format never became an open standard.
Why ACE is best avoided
Known vulnerabilities in ACE handling have been exploited in malware (some archive tools dropped or warned about ACE support as a result). Treat unexpected .ace files with caution.
If you must open a trusted ACE archive, extract it, then re-compress the contents to ZIP or 7z for safer long-term storage.