Does removing padding remove data or does it just remove what's not required

If say I use metaflac or ID3 to remove the padding for FLAC and MP3s'.

ID3.exe command:
ID3 -2 -s 0 "file"

metaflac.exe command:
metaflac --preserve-modtime --dont-use-padding --remove --block-type=PADDING "file"

If I use the commands for both to remove padding, does it affect any existing tags (remove them) or does it just remove what's not needed with regards to padding?

There is but one reason to use padding: since ID3v2 tags are stored at the beginning of the file, it would be a major pain to rewrite the entire multi-megabyte file to add a 50-byte frame. Padding reserves space in advance.

source : id3guide -

it's lossless

Thanks for the reply. I wonder if FLAC is the same with the metaflac command where it only removes what it needs to.

I haven't tried the ID3 tool and checked how it's handling the tag rewrites — so I can't tell if the rewrite is lossless.

But the metaflac command only removes the padding block and leaves the other data untouched.

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Thanks for that @Florian. How would the best way to test be? Add lots of tags and run the command to check?