Google yesterday released a 64-bit Windows version of Chrome, touting it as a performance and stability improvement over the six-year-old 32-bit edition.
In early June, Google promoted the 64-bit version to its preview channels, including the rough-edged "Dev" build line. On Tuesday, the company pushed the browser into the "Stable" channel, its most polished.
Chrome 37 64-bit is twice as stable as the 32-bit version, and decodes high-definition YouTube videos 15% faster, said Will Harris, a Chrome software engineer, in an entry on a company blog.
The Windows 64-bit Chrome requires Windows 7 or Windows 8.
For now, said Harris, 32-bit Chrome will remain the default offered to users. That means Windows customers who want to switch must re-download the 64-bit version from Google's website.
The stumbling block to 64-bit adoption is the lack of support for older, 32-bit plug-ins such as Google Voice and Google Earth. Google has tested the current generation of the 64-bit NPAPI plug-ins for Oracle's Java and Microsoft's Silverlight, and confirmed that they work, however.
NPAPI (Netscape Plug-in Application Programming Interface), harks back to -- not surprisingly -- Netscape, the 1990s browser that Microsoft drove into oblivion. Google has already blocked all but a handful of NPAPI plug-ins from running in 32-bit Chrome, although a few have been whitelisted and will still work, like Microsoft's Silverlight.
"The 32-bit channel will remain fully supported for the foreseeable future and we will continue to support 32-bit plugins until NPAPI is removed from Chrome," said Harris yesterday. There is no timeline for that scrubbing of NPAPI from the browser -- previously, Google promised that already-installed plug-ins will continue to run -- but next month Google will yank apps and add-ons which use NPAPI from the Chrome Web Store.
Google has been slower than most rivals in offering a 64-bit browser.
Apple's Safari has been 64-bit on OS X since 2009's version 4, which launched alongside OS X Snow Leopard. Microsoft's Internet Explorer has been available in 64-bit since 2006's IE7, while Opera Software, the Norwegian browser maker known for its same-named desktop flagship, also offers a 64-bit edition on Windows.
Google also offers a 64-bit browser for Linux, and one for OS X reached the beta channel earlier this month.
Mozilla is the last hold-out among the top five browsers on Windows. Although the open-source developer has long had 64-bit versions of Firefox for OS X and Linux, it has yet to push a 64-bit Windows edition into its prime release channels. However, one is available on Mozilla's "Nightly" build line, a very unpolished edition. The Nightly 64-bit Firefox on Windows can be downloaded directly from Mozilla's FTP server (download installer).
A pair of Firefox derivatives -- Pale Moon and Cyberfox -- are available in 64-bit editions on Windows. Both are based on Mozilla's source code.
Chrome 37 64-bit for Windows can be downloaded from Google's website. Users must click the "Windows 64-bit" link to retrieve the browser.