Firefox 19 debuts a built-in PDF viewer and other improvements

Mozilla has released Firefox 19.0 FINAL for desktop. There are only two notable new features in this new build, but after months stuck in beta, Mozilla has finally enabled its built-in PDF viewer, which allows users to view PDFs directly in the web browser without having to use a third-party viewing utility.

The other major new feature is a security one, with the Firefox Awesomebar now set up to alert users if the default search provider has been changed. In the meantime, Firefox 19.0 for Android -- due for release imminently -- will introduce support for themes, plus lower its system requirements to extend its reach to as many as 15 million more smartphones.

The new inline PDF viewer has been available in Aurora and Beta builds for a number of months, but Mozilla has finally pushed it through to the final build, despite the fact Mozilla has acknowledged the existence of "several UX/rendering/stability concerns", which it believes can be quickly hotfixed should any issues become major.

The PDF viewer, which should automatically kick in when a link to a PDF file is clicked, provides users with a number of useful tools via a toolbar at the top of the page -- users can quickly move between pages, plus access a slide-out pane that provides thumbnail page views and access to any outlines embedded into the PDF document. In addition, users can access zoom, print and download the document via conveniently situated buttons, plus switch to "Presentation mode" to view the document in full-screen mode.

Users can disable the new inline viewer in favor of their previous settings by opening the Firefox menu and selecting Options > Options. Switch to the Applications tab, scroll down to Portable Document Format (PDF) and click the Preview in Firefox dropdown menu to switch to another option, such as a third-party plugin, download file or "Always Ask".

The other new feature in Firefox 19 FINAL is security related -- Firefox will now alert the user and offer to automatically reset the default search provider if it’s changed by a third-party tool or through the about:config dialog.

Other changes in Firefox 19 include startup performance improvements, HTML5 enhancements involving various CSS properties and some developer tweaks, including a new Browser Debugger for add-on and browser developers. This feature is experimental and is currently disabled -- users can switch it on via the about:config menu -- set devtools.chrome.enabled and devtools.debugger.remote-enabled to true. Once done, restart Firefox and the feature will be accessible via the Firefox > Developer menu.

The principle change coming in Firefox 19 for Android is support for themes, allowing users to customize the browser’s look and feel. Version 19 also sees a lowering of Firefox’s system requirements. Previous builds required an 800MHz processor, but Firefox 19 will now run happily on 600MHz devices, along with 512MB memory and a HVGA (480×320 pixels) resolution. This extends the browser’s reach to more low-end phones, including HTC’s Wildfire S and the LG Optimus One.

Firefox 19.0 FINAL is available now as a free, open-source download for Windows, Mac and Linux.