MetaPDF highlights missing letters, OR highlight adjustments



Continuing to enjoy MetaPDF. This is minor concern, but one of those things that breaks up workflow and over the course of a long day of reading can start to drive me batty.

There’s an occasional tendency for highlights/underlines to miss characters at the beginning/end of a selection eg:


In this case, missing the opening parethesis is not a big deal, but other times it happens to words where the first character is dropped. Not critical, but mildly irritating. It also occasionally happens that I make a highlight and because of user error, I don’t quite highlight the whole sentence or something.

As such, it would be nice to be able to make adjustments to previous highlights. One possible mechanism would be to allow new highlights to merge with old ones (so in the previous example, if I start a new highlight a bit to the left and overlap the current highlight, they would merge). If this is difficult to implement, perhaps being able to select multiple highlights and have a “merge” option would be possible?

That said, I also really like the fact that I can use multiple annotation styles on the same test (eg highlight a paragraph in yellow and underline a citation within that paragraph in green), so I wouldn’t want any fix to my current annoyance to disrupt that bit of functionality.


Behind the hood we are using PDFjs, which does a really great job. It renders the PDF as an image and overlays an invisible text layer so that one can select the text. Sometimes the overlay is not 100% perfect, and that is why some letters are missing. PDFjs is updated frequently and we expect this will get better over time.

Exactly for these use cases we made the highlight text displayed in the left panel editable. Just double click on the text and you will be able to edit it. I have attached a screen shot to illustrate the procedure.


Cool, thanks for the response. Hopefully it will get better over time (nice to have tools that other people are building so you don’t have to worry about every detail!), and the ability to edit will probably fix 90% of my issues. Thanks for pointing it out!


That is nice (although I like the ability of xodo pdf view to move the boundaries of the highlight).

Would it be possible to let a user specify that two sequential highlights in the left column should be merged? I am thinking especially in the case of page breaks, where I want to highlight one passage that is crossing over a page break.


Another problem is that it marks the whole document, instead of only the selected part.
See >


I have a related problem. Often when I try to highlight text, the highlighter does not colour the last line of text. For example, below I tried to highlight “ethnic minorities make up significant proportions of the British labour force. For instance, in 2005”, which appears correctly on the left, but in the document the yellow part only covers the first line, not the second.

This is not a dealbreaker but it’s rather annoying, and other PDF editors I’ve used do not have this problem.


Are you by chance using the viewer at and not the one built in to Paperpile? We fixed this a while ago in Paperpile but have not yet ported it to the general-use version.