Every computer user – and hence every developer – needs to view pdf files from time to time. Adobe’s pdf viewer is the bloatware par excellence, slow and famous for its security problems. Security problems which make you need to update it every week or so.

Firefox has a built-in pdf viewer. But the pdf viewer that is built into Firefox is also quite slow and it creates very often a terrible ugly scripture. Sometimes, the text is nearly unreadable with the Firefox built-in pdf viewer. See this example, it is at zoom factor 100%, rendered with the Firefox 26.0 built-in pdf viewer.

The scripture is ugly, isn’t it?  After some search, I came across SumatraPDF, and I’m using it ever since. I love it. It is

• lightning fast
• lightweight
• creates readable and beautiful text
• probably much more secure than Adobe’s viewer
• open source

Here is the same text rendered with SumatraPDF 2.4, at zoom factor 100%:

Can you see the difference? The letters are much prettier and they are not intermingled falsely as with Firefox’ viewer.

I highly recomment SumatraPDF. Not only me, but also the Free Software Foundation.

 How to make SumatraPDF the viewer used by Firefox:

1. Install SumatraPDF.
2. Open the settings dialog in Firefox.
3. Select the applications tab.
4. Scroll down to Portable Document Format (PDF).
5. In the dropdown-box, select SumatraPDF Browser Plugin.

What is your favourite PDF viewer and why?