Does Add Prefix/Suffix handle very long lines?

Yes. Individual lines of any length are processed fine. Only total document size (memory) is a practical limit.

Does Add Prefix/Suffix store or log what I process?

No logs, no history, no database. The content you paste into Add Prefix/Suffix exists only in memory for as long as the tab is open.

Instant, because nothing is uploaded. Your input is processed on your own CPU the moment you hit run, with no round trip to a server.

Yes, both Windows (CRLF) and Unix (LF) line endings are understood. Output uses the LF convention, which works everywhere.

Insert a prefix and/or suffix into the content of each line.

Prefix

Suffix

Input

Ctrl ↵

Output

Ctrl↵run toolCtrlKsearch/searchEscclose

Does Add Prefix/Suffix handle very long lines?: Yes. Individual lines of any length are processed fine. Only total document size (memory) is a practical limit.
Does Add Prefix/Suffix store or log what I process?: No logs, no history, no database. The content you paste into Add Prefix/Suffix exists only in memory for as long as the tab is open.
How fast is Add Prefix/Suffix?: Instant, because nothing is uploaded. Your input is processed on your own CPU the moment you hit run, with no round trip to a server.
Does Add Prefix/Suffix support Windows CRLF line endings?: Yes, both Windows (CRLF) and Unix (LF) line endings are understood. Output uses the LF convention, which works everywhere.