can you PLEAZE add a trim end to delete the last space when double clicking on a word. Firefox add by default a space to the selection if there is one after.
So e.g : hello bob double clicking hello will select "hello " and so in hello=bob "hello" won't be selected.
Add an option automatically delete last space.
Other thing: on github pages the addon doesn't work.
I will change my note after the first fix.thanks

Doesn't need notification permission.

Doesn't work. Does absolutely nothing at all. Neither Native or Custom mode works. Firefox 79.

not work

This could be a very useful tool if it wasn't so erratic. It is very hard to use. Highlight a word and the menu doesn't always come up or if it does, either the menu disappears before you can click on it or the highlighted text loses its highlight Nor when a word ts highlighted, does it highlight every instant of the word. If a mistake is made and you try to delete it, it removes all highlighting as well as the mistake and then the extension will not work at all. It would be helpful if there was a drp down menu on the right click. All in all, it is a very frustrating tool.
One serious problem is that if a one or two syllable word is highlighted and the same syllables appear in three or more syllable words, the one or two syllables are highlighted in words with more syllables. Example: highlight the word "sane" and the letters will be also highlighted in the word "insane."
Another problem is that if by mistake not every letter is selected in a word that is highlighted and the user later tries to correct this by selecting either the entire word or the missing letter or letters and highlight them, HIGHLIGHT ALL will highlight the missing letter(s) and split the word into two parts while highlighting all of them.
In response to an earlier comment herein about the difficulty of deleting an erroneous highlight without removing all the highlighting in the document, the app author suggested clicking on the erroneous highlight and deleting it. It doesn't work and remains a serious defect.

Worked up to the point of actually trying to highlight multiple words/sentences. Out of all the colors I had customized for myself only 3 worked. Then it started "crashing" and wouldn't highlight at all.

Straight-up does not work at all.

just doesnt work!.. i dont know why.. no icon the find is the same no change

Didnt seem to work at all. Im on windows using firefox 65.0.2 (64-bit). I wanted to see highlighting in the scrollbar but did not.

Sadly It does not work for a bigger pages.

Doesn't work.

Highlight disappears with one mouse click.
Can only highlight one keyword at a time.

Not working at all!

Why does this want access data for all websites? That's ridiculous and suspicious.

Search markers doesn't work. windows 7 x64, FF 59.0.1 x64
custom highlighting option doesn't save. maybe thats the reason
Addon doesn't work at all, nothing happen when addon is on, or off, no difference in ff behavior.

Makes Copy/Paste Hotkeys stop working. Must right click and choose "Copy" to copy anything. High drain for a simple funciton, disabling core functionality makes it big mistake though it sounds rather helpful.

Activates with ctrl+F8. I have a macbook, and my keyboard does not have F8. Went to website and could find no information on this.
Please make this more mac friendly.

Just updated from Firefox 54 to Firefox 56 and it doesn't work in 56. This is already known and the developer has retooled it for Firefox 57; this review is just to let any other new Firefox 56 users who don't want to install Firefox 57 know that Highlight All is the culprit causing anomalies in their new Firefox 56 upgrade. I have about thirty extensions installed and I had to disable them one by one to find out it was Highlight All interfering with keyboard shortcuts. Unfortunately no version of Highlight All works in Firefox 56 and I don't want to upgrade to 57 and risk losing even more extensions, so for me Highlight All is no more. Regrettably, unless a rollback version is created (which is admittedly a lot to ask), I must snuff four stars that once blazed bright.