[JeanMarcS]

Don't know about the code subtilities, but SumatraPDF is a gift for viewing PDF on MS Windows. So big thanks to the author !

[Arainach]

Out of curiosity, what's your use case for it? Years ago I preferred Sumatra/Foxit to Adobe, but every major browser has supported rendering PDFs for at least a decade and I haven't had needed or wanted a dedicated PDF reader in all that time.

[sameerds]

Opening a pdf inside a browser feels to me like an application inside an application. My brain can't handle that load. I would rather have the browser to browse the internet and a pdf reader to display pdfs. If I clicked on a link to a pdf, it is _not_ part of the web, and I want the browser to stay out of it. Same goes for Office 360 wanting to documents inside my browser. I don't want it to do that. I have the necessary apps installed for it.

[drewbitt]

Not only is it faster in opening than a browser and a separation of concerns (documents get their own app, which I can leave with open tabs), it also opens epub, .cbz, and other formats, so I have it installed on all my Windows machines. I eventually open a book.

[mjmas]

Part of why I use SumatraPDF is that it automatically reloads its view when the files change (at least for PDFs, I haven't tested on the other file types it supports).

[vachina]

> use case

Sumatra excels at read-only. Usually anything to do with PDF is synonymous with slow, bloat, buggy, but Sumatra at just 10Mbytes, managed to feel snappy, fast like a win32 native UI.

[lenkite]

> I haven't had needed or wanted a dedicated PDF reader in all that time.

OK. Now load 100 PDF's. You will need a dedicated PDF reader unless you don't mind wasting a truckload of RAM. Also, browser PDF readers are generally slower and are not optimal at search/bookmarks/navigation/etc.

[MC995]

I use my browser for most PDFs. But for PDFs that have a lot of vector graphics and are over 50-100mb, the browser viewer is very slow to load and render the pages. Even zooming in on a part of a drawing can take 10-15 seconds in the browser which is pretty disruptive.

Sumatra has no issues with 200mb+ PDFs, or ones with complex drawings.

These are all engineering drawings such as mechanical, electrical, and architectural drawings, so mine might not be a use case everyone has.

[Cadwhisker]

It's smaller, lighter and much faster than launching a web browser to view a PDF. I can configure it to open a new instance for each PDF which is nice if you need to have several docs open at once. Again, nothing that you can't do with a browser and dragging tabs, but I prefer this.

[df0b9f169d54]

As I still recalled it's possible to configure an external editor so that when you click on any place on sumatraPDF viewer you can open the source file that is annotated with the clicked position. This is extremely helpful when working with LaTeX documents.

[graemep]

Large PDFs are very slow in browsers. I believe they all use pdf.js (or similar).

[agent327]

Sumatra will reload any PDF that changes while you are viewing it (Adobe locks the file, so you can't change it to begin with). This is incredibly useful when you are writing documentation using a document generating system (like docbook).

[vgb2k18]

If you hate it when pdfs won't print because of restrictive permissions... Sumatra.

[ternaryoperator]

Not the OP, but my use case is epub books, which it handles flawlessly.

[eviks]

How do you alt tab to a browser tab with a PDF? How do you change navigation shortcuts when browsers are notoriously bad at such customizations?

[dolmen]

It is not sandboxed.

So one can expect zero day exists and are exploited.

That may not be a feature for you, but it is for attackers.

[wavemode]

opening (and browsing/searching through) a very large PDF is a nightmare in most browsers

[NooneAtAll3]

in my experience, browser pdf viewers take a loooot more RAM than Sumatra