Products · Product
PDF.js
Raised as a usability problem by 16 people on Hacker News over 14 years (2012–2025), in 11 threads.
No issue was raised by at least 3 people in 3 threads this year.
No issue was raised by at least 3 people in 3 threads in the last 5 years.
- 1
Every issue, all time, most people first
Large PDFs load, scroll and search slowlyUnreviewed
20122026- Large PDFs load slowly and scroll and search slowly2021-02-08
- PDFs feel sluggish; zooming is not instant, especially for vector graphics2014-05-22
- Opening a 15-page PDF takes two minutes, blocking users from doing their work2014-05-09
Unreviewed issues were grouped by machine: Claude Haiku labelled each comment as a usability complaint, named what it's about and summed up the problem in a line, and a small model grouped similar problems. Nobody has checked them by hand. Expect mistakes.
The newest 20 complaints
- Keyboard navigation keys don't work in Firefox and scrolling renders blurry, slow pages2025-08-15
- Developers struggle to build custom viewers because the API is confusing and incomplete2021-10-15
- Large PDFs load slowly and scroll and search slowly2021-02-08
- Hjkl keys scroll jerkily instead of smoothly, making arrow-key scrolling cumbersome2020-09-22
- Copied text splits words and letters onto different lines2018-12-13
- PDFs feel sluggish; zooming is not instant, especially for vector graphics2014-05-22
- Opening a 15-page PDF takes two minutes, blocking users from doing their work2014-05-09
- Large PDFs lag and jerk when scrolling, freezing Firefox2014-05-09
- Scrolling PDFs stalls for 2-5 seconds each time, making real work frustrating2014-05-09
- Manuals from Automation Direct are very slow to open and navigate2014-05-08
- Opening PDFs with many pictures, vector graphics, or pages is too slow2014-05-08
- Paging quickly through a book lags, forcing waits for pages to render2014-05-08
- Navigating between pages is so slow it's horrible compared to Adobe Reader2014-05-08
- PDF viewing is so slow and CPU-heavy that the user avoids it2014-05-08
- Some PDFs are so slow to open or render they feel unusable2014-05-08
- Viewing documents is noticeably slower than in Preview.app2014-05-08
- Error tells users to submit patches, so non-programmers can't fix or proceed2014-03-17
- Saved PDFs turn into HTML files that no PDF reader can open2014-03-04
- Too slow to use, and search misses pages not yet viewed2012-09-15
- Extremely slow on large image-heavy PDFs2012-09-14