Very useful for replacing CDNs when they're not available.

An example which may help someone:

Format: %https%//cdn.jsdelivr.net/npm(.*)
Destination: %https%//unpkg.com\1

Replace "%https%" with "https:"

Appears to work fine for URLs in image src tags as well

Works well, but lack of examples/documentation means that you have to experiment a lot before getting it to do what you want.

Works well with correct syntax.
E.g.
https://www.reddit.com/(.*)
-->
https://new.reddit.com/\1

Works as advertised.

This Firefox addon (and its code) does exactly as described! No-frills redirect for user-specified domains that need redirection.

doesnt work

類似のアドオンの中では一番うまく動きましたが、サイトによっては失敗します。
https://www.reddit.com/(.*) ---> https://old.reddit.com/(.*)

Lack of documentation and not working even after trying various regex formats.

It works for me. It could provide better manual and more examples.

Does not work

Doesn't seem to work. https://github.com/duangsuse/WebExt-URLReplace/issues/3

Шикарно работает! Заменяет не только в адресной строке, но в коде страницы.