Annotation Support


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.

Highlight a text!?

This is tracked by


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

Sumatra Highlight Helper is really “feature request ware”. I hope someone likes the features and implements them into Sumatra PDF.

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!