You click a PDF link. Blank tab. Or download. Or error. The browser used to just show it; now it doesn't.
What's actually going wrong
Browser PDF viewer disabled. A setting change or extension turned off the built-in viewer. PDF download set as default. The browser is downloading PDFs rather than opening them. Conflicting extension. An extension hijacks PDF handling. File issue. The PDF itself has problems and the browser is silently giving up.
If every PDF fails in the browser, it's a settings or extension problem. If only one specific PDF fails, it's the file.
The quick fix
Chrome/Edge: Settings > Privacy and security > Site settings > Additional content settings > PDF documents. Toggle 'Download PDF files instead of automatically opening' OFF.
Firefox: Settings > General > Applications > Portable Document Format > set to 'Open in Firefox'.
If the PDF still won't open, disable extensions one by one. A common culprit is any 'PDF download' or 'document manager' extension that intercepts handling.
If that didn't work
If only one specific PDF won't open in the browser, download it (right-click > Save link as) and open in a desktop reader. If it opens locally, the browser viewer is choking on something specific to that file.
For PDFs that won't open anywhere, upload to Flint — the more forgiving parser often opens files browsers refuse.
Prevent it next time
Keep your browser updated. Be selective with PDF-handling extensions — many cause more problems than they solve. And know your settings: a few minutes once means PDF handling works for years.
FAQ
How do I make Chrome open PDFs in the browser instead of downloading?
Settings > Privacy and security > Site settings > Additional content settings > PDF documents. Turn OFF 'Download PDF files instead of automatically opening them in Chrome'.
Why do some PDFs open in the browser and others don't?
Modern PDFs use features the browser viewer supports. Files with quirky structure, unusual fonts, or specific encryption schemes can trip the viewer. Download those and open in a desktop reader.
Should I install a PDF extension?
Usually no. Modern browsers' built-in viewers handle 95%+ of PDFs well. Extensions add another failure point. Only install if you have a specific need (annotation, form filling) the browser can't handle.
Why does my browser download every PDF now?
Setting was changed (often by an update or extension). Re-enable browser PDF viewing in your browser's PDF settings.
Browser PDF issues usually solve in settings. For genuine file problems, Flint opens what browsers won't.