mozilla/pdf.js

PDF Reader in JavaScript

Stars: 53.9k
Forks: 10.7k
Open beginner issues: 1
Indexed issues: 372
Avg merge: 18h 38m
Merged PRs (30d): 130

Dominant language: JavaScript
License: Apache-2.0
Last GitHub push: Sep 19, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: No beginner labels indexed

Beginner friendly Everything

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369 open issues indexed

Intermittent failure in the `doesn't jump when moving selection` text layer integration test Open

intermittent test

Difficulty 4/5 3-5 days Newbie friendliness 52/100

mozilla/pdf.js#21978 · Opened Sep 17, 2026
[Bug]: Combination of defaultZoomValue: page-height and scrollModeOnLoad: 3 = unable to scroll past page with keyboard Open

requires-feedback-from-ux-ui viewer

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/pdf.js#21974 · Opened Sep 17, 2026
[Bug]: Deleted trailing pages return when downloading after restoring page order Open

editor

Difficulty 3/5 1-2 days Newbie friendliness 74/100

mozilla/pdf.js#21971 · Opened Sep 17, 2026
[Bug]: `/GoToE` doesn’t work descendants other than children Open

core

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#21959 · Opened Sep 15, 2026
[Feature]: Default to custom page range when sidebar selection exists Open

feature requires-feedback-from-ux-ui viewer

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/pdf.js#21958 · 1 comment · Opened Sep 14, 2026
[Feature]: Hold shift to select a continuous range of pages in sidebar Open

feature requires-feedback-from-ux-ui viewer

Difficulty 3/5 1-2 days Newbie friendliness 62/100

mozilla/pdf.js#21957 · Opened Sep 14, 2026
Intermittent failure in the `should keep an ink annotation on a pasted and moved page` reorganize pages integration test Open

intermittent test

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/pdf.js#21954 · Opened Sep 13, 2026
[Bug]: Text in a specific fillable form field of a pdf isn't being saved Open

form-xfa

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/pdf.js#21904 · Opened Sep 7, 2026
[Bug]: getTextContent inserts a space after a multi-code-point Indic glyph with nonzero width Open

text-selection

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/pdf.js#21890 · Opened Sep 6, 2026
[Feature]: A way to set an exact value to the sliders. Open

feature requires-feedback-from-ux-ui viewer

Difficulty 3/5 1-2 days Newbie friendliness 58/100

mozilla/pdf.js#21881 · Opened Sep 3, 2026
[Feature]: I would like a way to view a PDF in the preview pane via a right-click context menu option. Open

chrome-extension feature

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/pdf.js#21877 · Opened Sep 3, 2026
[Feature]: "Page Scrolling" mode needs touch control for tablet use Open

feature requires-feedback-from-ux-ui viewer

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/pdf.js#21805 · Opened Aug 20, 2026
Proposal: show existing keyboard shortcuts in toolbar tooltips Open

requires-feedback-from-ux-ui ux viewer

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21765 · Opened Aug 12, 2026
[Bug]: indicate modifications after digital signature Open

digital-signatures

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/pdf.js#21698 · 2 comments · Opened Aug 3, 2026
[Bug]: edited PDF document still contains signature information Open

digital-signatures

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#21696 · Opened Aug 3, 2026
Do we still need the separate `enableMerge` and `enableSplitMerge` options/preferences? Open

viewer

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21679 · Opened Aug 1, 2026
[Feature]: Multi-select Open

feature text-selection viewer

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21670 · Opened Jul 31, 2026
[Feature]: Document the `search=` "Option after the #" Open

other

Difficulty 1/5 Under an hour Newbie friendliness 85/100

mozilla/pdf.js#21645 · 1 comment · Opened Jul 27, 2026
[Bug]: Overlapping annotations can be clicked through editor toolbar Open

editor

Difficulty 3/5 1-2 days Newbie friendliness 58/100

mozilla/pdf.js#21643 · 5 comments · Opened Jul 27, 2026
[Bug]: Obsidian-exported PDFs have broken text inside highlighted boxes when viewed on Firefox Open

font-type3 regression upstream

mozilla/pdf.js#21610 · 6 comments · 1 assignee · Opened Jul 21, 2026
[Bug]: Broken rendering of Ikea manual Open

core os-android

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#21542 · 2 comments · Opened Jul 5, 2026
[Feature]: Show page-span indicators in the document outline sidebar Open

feature requires-feedback-from-ux-ui viewer

Difficulty 5/5 Over a week Newbie friendliness 45/100

mozilla/pdf.js#21509 · 2 comments · Opened Jun 27, 2026
[Bug]: Opening editor toolbar falsely enables hidden highlights Open

editor

Difficulty 3/5 1-2 days Newbie friendliness 62/100

mozilla/pdf.js#21498 · 3 comments · Opened Jun 24, 2026
[Feature]: Auto-update ToC/Outline item while scrolling Open

feature requires-feedback-from-ux-ui viewer

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21422 · Opened Jun 9, 2026
[Bug]: [PDF Viewer Extension] PDFs get closed automatically after Chrome relaunch, if they have been inside a tab group Open

chrome-extension

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#21410 · 4 comments · Opened Jun 8, 2026
[Bug]: Annotation editor preview does not match the final rendered PDF Open

editor

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/pdf.js#21401 · 2 comments · Opened Jun 7, 2026
[Bug]: Incorrect rendering of some fonts at intersection of shapes Open

font-conversion upstream

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#21353 · 9 comments · Opened May 28, 2026
Update the Babel plugin to remove unused top-level constants Open

other

mozilla/pdf.js#21337 · 3 comments · 1 assignee · Opened May 26, 2026
[Bug]: wrong bullet points on Edge Open

edge-specific font-conversion

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/pdf.js#21303 · Opened May 20, 2026
[Feature]: Feature request: configurable Ctrl+scroll wheel zoom sensitivity Open

feature requires-feedback-from-ux-ui viewer

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#21297 · Opened May 19, 2026
[Feature]: Homogénéité du style Open

requires-feedback-from-ux-ui ux viewer

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21250 · 2 comments · 4 reactions · Opened May 10, 2026
[Bug]: Toolbars not being dismissed after using tool in different pages, having deleted a page Open

split-merge-organize

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#21241 · 2 comments · Opened May 8, 2026
[Feature]: Support for setAtttachment() Open

feature requires-feedback-from-ux-ui

Difficulty 5/5 Over a week Newbie friendliness 35/100

mozilla/pdf.js#21212 · 1 comment · Opened May 2, 2026
[Bug]: display look very broken when the window is very small Open

viewer

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#21119 · Opened Apr 19, 2026
[Bug]: PDF completely black after computer idling overnight. Open

other

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/pdf.js#21009 · 1 comment · 1 reaction · Opened Mar 30, 2026
[Bug]: `/Subj` not shown in text annotation (only `/T`) Open

annotations

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#20987 · Opened Mar 26, 2026
[Feature]: Keyboard navigation in table of contents Open

feature ux viewer

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#20962 · Opened Mar 23, 2026
[Bug]: annotation icon colors don’t follow their specified color Open

annotations

Difficulty 3/5 1-2 days Newbie friendliness 48/100

mozilla/pdf.js#20938 · 1 reaction · Opened Mar 21, 2026
[Bug]: Fix GitHub workflows errors for bot users Open

test

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/pdf.js#20813 · 3 comments · Opened Mar 5, 2026
[Bug]: PDF title displayed incorrectly when multiple language titles present in XMP metadata Open

core

Difficulty 3/5 1-2 days Newbie friendliness 58/100

mozilla/pdf.js#20801 · 1 comment · Opened Mar 4, 2026
[Bug]: Screenreader support in PDFjs 5.x not working as expected Open

accessibility

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/pdf.js#20790 · 1 comment · Opened Mar 4, 2026
[Bug]: pdf.js doesn't lex `5f` properly Open

corrupted-pdf

Difficulty 3/5 1-2 days Newbie friendliness 48/100

mozilla/pdf.js#20735 · 3 comments · Opened Feb 25, 2026
[Bug]: Comment/highlight buttons cut off at bottom of page Open

editor

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/pdf.js#20700 · Opened Feb 21, 2026
[Bug]: Standard `viewer.html` uses unnecessary tabindex on `#viewerContainer` element Open

accessibility viewer

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

mozilla/pdf.js#20674 · 2 comments · Opened Feb 17, 2026
[Bug]: `/GoToE` links not working when `/R /P` (relation is child) Open

core

Difficulty 4/5 3-5 days Newbie friendliness 42/100

mozilla/pdf.js#20672 · 1 comment · Opened Feb 17, 2026
[Feature]: implement the `ef` parameter (RFC 8118, section 3) Open

core feature

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#20671 · Opened Feb 17, 2026
[Bug]: viewing list of annotations should not dirty the document Open

viewer

Difficulty 3/5 1-2 days Newbie friendliness 48/100

mozilla/pdf.js#20647 · Opened Feb 11, 2026
[Bug]: Toolbar page number input allows invalid range, causing silent no‑op Open

requires-feedback-from-ux-ui

Difficulty 3/5 1-2 days Newbie friendliness 55/100

mozilla/pdf.js#20619 · 5 comments · Opened Feb 2, 2026
[Feature]: Zoom modes "Content Fit"/"Content Width" Open

feature requires-feedback-from-ux-ui viewer

Difficulty 5/5 Over a week Newbie friendliness 45/100

mozilla/pdf.js#20574 · 2 comments · 1 reaction · Opened Jan 14, 2026
[Feature]: Remember Last Zoom Open

feature requires-feedback-from-ux-ui viewer

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/pdf.js#20545 · 3 comments · Opened Jan 2, 2026

A short digest of beginner-friendly GitHub issues.