The idea is good, a much needed extension after Mozilla killed all regex addons, but it doesn't work.
On my updated waterfox, (foo|bar) only worked once, but it only matched "foo"

An invaluable extension for me, the developer is a hero :)

Note that you can also use Ctrl+Shift+F to open the dialog. Press Enter in the regex box to search, Shift+Enter to highlight all matches.

Works as described; ability to save and edit profiles is great.

Handy add-on. It increased my productivity.

Thanks to Mohd (the developer). He responds to issues/suggestions (on GitHub page), too.

The add-on doesn't fully work, and for as far as it does, is not very practical.
- I type in a regex and do 'search' but it doesn't always show the results it should. Oftenly it shows nothing in the result box, sometimes just one result where there are many more.
- The highlight function does find all matches. However, it would be nice if the page could jump to the first/next result, but that's probably what the search button is supposed to do.
- When using the highlight function without the 'global' flag, a result is that is not the first one may be highlighted, rather a random(?) one.
- It seems that this addon looks for matches in the html source code rather than the actual page. Therefore it also seems to match classnames, image paths etc. This is not great and the highlight function therefore has matches that can't be seen on the page!

It's a nice add-on, but could use some improvement!

Great! It does just what I need. By pressing Highlight button, extension highlights regex matches and you can save regex for later use.

I like the recent Highlight feature that's been available since version 1.0.4 (for some reason only available as a download from the author's GitHub page), but it has one side-effect that has a massive potential of breaking websites. The highlight is not only applied to visible text within tags, but to the whole page ( document.body.innerHTML ). This can break inline JavaScript, link references and all kinds of other things as well if a match is found, which sadly makes it unusable as the multi-word highlighter that I've been looking for.

For other use cases, such as extracting data from the page source, it's a neat extension but I have no such requirements myself.

There are newer version of extension in the Github. Please deploy the latest version in the Firefox repository.

This extension desperately needs use instructions. I haven't worked out how to get it to highlight text in a webpage that matches a regular expression, which is what I want, and what I thought the description said it would do.

There's no 'use RegEx' option when I type Ctrl+F, and when I click 'Preferences' on this extension, there are no options, and nothing that says what to type to make it work. I did eventually notice the 'Regex Search' button in the toolbar, but clicking that opened a confusing dialogue box, and when I typed a very simple JavaScript-style regex, it didn't seem to find anything on the page I'm on.

Perhaps I'm missing the point of this extension, but either it doesn't do what I want, or the UI is terrible. Sorry.

Would be great to also have the ability to search and replace.

Couldn't wrap my head around how it works. The interface is confusing. I just want a way to CTRL + F a page and highlight results using regex. I couldn't figure out how to do it with this addon.

Does what it promises. Would be great if you could explain the functionality a little bit more. I cant get my head around the template thing.

I too was hoping to see the search terms highlighted in the page. I just installed it so I know I have the latest version. Dev says it highlights on the page but I'm looking at the search it found and looking at the section of the page where I can see the term I searched for - it is not highlighted!

I have to copy the text in the result field then use Firefox's search (ctrl+f) to highlight the search terms found.

Limited usefulness as it currently stands but with Firefox 57, this appears to be the best out there.

UPDATE: I visited the github link you posted in your reply but only saw the XPI file for Windows - will this also work on Linux? (I wonder why there isn't an option to reply to a developer response!)

This extension doesn't do a great job at explaining what it is. I was hoping to be able to search for an expression and highlight results on the page, like cmd+F but with regex instead of simple string matching. This extension basically just greps the HTML for your expression and gives the results.