when exporting, does it re-compressn?

hi guys
like the titile says. when i export a file to say wav, then edit it and export again to replace it, does audacity re-encode the file, or no becasue of the same extension?

Yes only because Audacity edits internally at 32-bit floating, not plain 16-bit. It does this because some of the tools and filters cause an accidental overload condition that in 16-bit would destroy your show. In 32-bit, it’s a very minor inconvenience.

It kills scientists that the input file and the output file are not surgically the same. The audio people don’t care. Having said that, Audacity will not edit MP3. That input and output conversion creates sometimes serious damage every time and you can’t stop it.

Koz

“WAV” is not a compressed format, so there is no compression when exporting as WAV.

Audacity works with ultra-high quality “32 bit float PCM” data.
When you open / import an audio file, Audacity copies the audio data from the file into the Audacity project (decoding it as necessary). You are therefore not actually editing that “file”, you are editing a copy of the audio data.

When you “export” an audio file, the audio data in the Audacity project is copied to the new file (encoding it as necessary). If you export in a compressed format (such as MP3), then yes, the audio data is compressed.

It is not generally recommended to overwrite the original file. It is much safer to export to a new file with a new (unique) file name.