pdf.js
Hacker ApprovedRanked 5 of 6 PDF readers by recommenders
Free PDF viewer built into Firefox and many websites, praised as clean, minimal and mostly safe. Common caveat: slower and less capable with very large files and editing.
Free PDF viewer built into Firefox and many websites, praised as clean, minimal and mostly safe. Common caveat: slower and less capable with very large files and editing.
14 people gave an opinion
- recommend it
- 10
- criticize it
- 4
- approval share
- 71%
Recommended in 8 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 10 people recommend itNeeds 10 or more, met.
- 2.5 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 8 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Built into Firefox and websites
“It's what Firefox uses, and most websites with integrated on-page PDF viewing functionality.”
Comment from 28 Oct 2026 in “The case of the 9 bit AES key” “it's been a helpful JS library for embedding PDFs on websites”
Comment from 22 Jan 2026 in “Take potentially dangerous PDFs, and convert them to safe PDFs” Mostly safe, sandboxed design
“pdf.js is considered mostly safe, and updated.”
Comment from 18 Dec 2025 in “We pwned X, Vercel, Cursor, and Discord through a supply-chain attack” “In theory, it's as safe as loading a webpage.”
Comment from 22 Jan 2026 in “Take potentially dangerous PDFs, and convert them to safe PDFs” “a clean minimalist sandboxed PDF parser”
Comment from 16 Jun 2026 in “Google Chrome's Next Update Will Mark the End of Popular Ad Blockers” Clean and uncluttered
“Evince/PdfJS have way fewer buttons and clutter and pop-ups than the Adobe crap”
Comment from 10 Apr 2026 in “Veracrypt Project Update” “a clean minimalist sandboxed PDF parser”
Comment from 16 Jun 2026 in “Google Chrome's Next Update Will Mark the End of Popular Ad Blockers”
What people warn about
Each mark is one comment
Slow with very large PDFs
“It's still a slight performance regression for very giant pdf. But it is enough for most use case.”
Comment from 10 Nov 2025 in “XSLT RIP” “using pdf.js wasn't gonna work and be too slow and the wrong interface anyway”
Comment from 1 May 2026 in “Running Adobe's 1991 PostScript Interpreter in the Browser” Poor font support, can't edit images
“problems such as poor font support and barely any way to change existing images”
Comment from 7 Jul 2026 on Hacker News “poor font support and barely any way to change existing images”
Comment from 8 Jul 2026 on Hacker News
Other PDF readers people recommend
The four most recommended other PDF readers, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Apple Preview | 42 | 28 | 60% | 10 | — | — |
| Okular | 12 | 5 | 71% | 5 | — | Approved |
| MuPDF | 11 | 3 | 79% | 7 | — | Approved |
| SumatraPDF | 11 | 1 | 92% | 7 | — | Approved |
| pdf.jsThis page | 10 | 4 | 71% | 8 | — | Approved |
What people said
15 of the 16 comments that mention it, newest first. Each links to the original comment.
“It's what Firefox uses, and most websites with integrated on-page PDF viewing functionality.”
“Considering they’ve also made pdf.js, I have hope.”
“PDF.js was the best approach.”
“poor font support and barely any way to change existing images”
“problems such as poor font support and barely any way to change existing images”
“a clean minimalist sandboxed PDF parser”
“everything becomes extremely blurry when you zoom in for absolutely no reason at all”
“using pdf.js wasn't gonna work and be too slow and the wrong interface anyway”
“Evince/PdfJS have way fewer buttons and clutter and pop-ups than the Adobe crap”
“PDF.js has had many vulnerabilities as well”
“In theory, it's as safe as loading a webpage.”
“it's been a helpful JS library for embedding PDFs on websites”
“pdf.js is considered mostly safe, and updated.”
“This actually seems one of the more useful AI features I've seen.”
“It's still a slight performance regression for very giant pdf. But it is enough for most use case.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.