It would be so nice, if one could add simple (!) annotations, like marking text with different highlighters and adding footnotes, maybe in a seperate file, if support for PDF annotatins would be too complex. I think, that’s the only thing I am really missing from Sumatra, and why I still sometimes switch to PDF-XChange.
This is tracked by Add highlighting capability · Issue #185 · sumatrapdfreader/sumatrapdf · GitHub and Request for the hightlighter feature in sumatraPdf. · Issue #747 · sumatrapdfreader/sumatrapdf · GitHub
[LATER EDIT] above links are historic entries. This thread is now locked as the experimental Sumatrapdf Meta eXtension a.k.a. SMX feature has been retired. It is replaced in latest Pre-Releases by newer, more extensive PDF annotations features.
For current issues search forum or for github issues Search · is:issue sort:updated-desc annotation (github.com)
afaik the prerelease builds have basic highlight support
you’d select some text and hit the ‘h’ key to highlight
you need to save the document for the anonation to be stored inside the pdf
you can even chose the highlight color by editing the advanced settings file
Personally I’ve found the highlighting feature in the pre-release builds to be quite buggy. Trying to overlap highlighted areas or trying to de-highlight only a portion of a highlighted area or other such simple tasks often cause the program to crash. Probably that’s why the feature hasn’t been enabled for stable builds despite being available for ages.
in the advanced settings file find and set
SaveIntoDocument = false
this way the highlight will go in a text file with the same name as the pdf, and the pdf will remain unchanged
to remove a highlight just remove a line in the text file
this way sumatra supports highlight annonation not just for pdf but epub/mobi/chm/fb2… most formats
sumatra is the only reader that has highlight support for chm files (you’d need to set UseFixedPageUI = true for chm files)
Years ago I made sumatra_highlight_helper. It is a AutoHotkey helper script to add, remove and jump between different color highlights in Sumatra PDF reader.
I’ve now also put the code on GitHub
[Update] changed to work with recent pre-release now known as HighlightJump
Sumatra Highlight Helper Jump is really “feature request ware”. I hope someone likes the features and implements them into Sumatra PDF.
Older Screenshot gifs
I’m not sure but I think those crashes are new to the latest prerelease.
Perhaps. TBH I haven’t really bothered to test the feature all that much previously.
I’m a Washington, DC-based medical student and have been using SumatraPDF for over a year now. This feature is absolutely essential to my studies. Annotating First Aid, our Board exam review book, is a time-honored tradition. Unfortunately due to the lack of this capability I have had to switch to Foxit Reader. Hopefully they will add a few features and I can switch back!
Hi there,
I am using Sumatra v.3.1.2 x64
Why ctrl+mouse+h is not working for me for highlighting a text? Is there any other method using hotkeys or something else?
Thanks!
Highlighting is still buggy (and the dev who implemented it is no longer around), so it’s enabled only in the pre-release versions (select some text and press ‘h’). You can read more about it here and here.
Thanks SumatraPeter,
I thought that I am missing something.
Now removing the highlighting is really pain in the a*s. 
It would be awesome if sumatra could add in the possibility to highlight pieces of text. I use sumatra as my main pdf reader and it would be nice to have this option.
Extra features are in the pre release builds
I’ve tried the highlight feature, it would be better if I can save the highlight in situ, i.e. when I press ctrl+s, no need to pop up a window to confirm the over written. All other pdf readers is doing so.
Hi, I met the same problem. Have you gotten any solutions?
Hi, same question, hope to be able to save highlights in situ
Hi @dozi
Practically all editors file / modifiers require you to confirm Save otherwise you will over-write the previous copy.
SumatraPDF in common with many applications require you to save as a different name or location to protect unwary users from corrupting the source file.
I personally expect (and prefer) that when editing any file.
I want to highlight text with a yellow pencil… How do I do it?
@fernandoeliasdasilva: See the second post above.