Use Google Libraries: A Plugin to Improve Script Loading Performance in WordPress
Please use the support forum if you need assistance.
hosted on Google’s AJAX Libraries API.
This plugin allows your WordPress site to use the content distribution
network side of Google’s AJAX Library API, rather than serving these files from your WordPress install directly.
This provides numerous potential performance benefits:
- increases the chance that a user already has these files cached
- takes load off your server
- uses compressed versions of the libraries (where available)
- Google’s servers are set up to negotiate HTTP compression with the requesting browser
For a more detailed look see Dave Ward’s 3 reasons why you should let
Google host jQuery for
Supported Libraries and Components
use-google-libraries folder to the
Activate Use Google Libraries through the ‘Plugins’ menu in WordPress.
Er… That’s it really.
Q. What happens when Google updates their library versions?
A. Google has stated that they intend to keep every file they’ve hosted
available indefinitely, so you shouldn’t need to worry about them
Q. Why isn’t in doing anything?
A. Firstly, if you are using a caching plugin, flush the cache or
temporarily disable it to be sure it’s not doing anything. That said,
I’ve done my best to make Use Google Libraries gracefully step out
of the way when things are not as expected. While not, perhaps,
giving you the greatest benefit it helps ensure you site doesn’t just
flat out stop working.
In general, anything that calls wp_register_script and/or
wp_eneque_script before ‘init’ causes trouble for Use Google
Libraries. I’ve made an effort to force it to try and run anyhow,
so please report any issues with this. If you have ‘WP_DEBUG’
enabled, a message will be logged letting you know this is happening.
Please see the section on Incompatible Plugins and
Incompatible Themes for specific information.
Q. How do I use the libraries supplied by Use Google Libraries?
A. The same way you use them when Use Google Libraries isn’t installed using
‘wp_enqueue_script’. In fact you should develop your theme or plugin without
Use Google Libraries being enabled at all, then test it both ways.
Q. Why do some scripts continue to use the WordPress supplied versions?
A. Assuming some other plugin or theme isn’t the cause, Use Google Libries does
it’s very best to ensure your site behaves as it should when using the stock
WordPress scripts. If WordPress is asking for a version of a script that
Google isn’t hosting, then it will continue to use the WordPress supplied
Q. Can I always load the latest version of a hosted script?
A. No. Use Google Libraries doesn’t do that because it would almost certainly
break WordPress. Even if it didn’t, the less ‘version specific’ URLs supported
by Google’s CDN set a short term ‘Expires’ header, so there wouldn’t be much
I’ve had scattered reports that UGL is stepping out of the way when
If you’re going to flag the plugin as “broken” in the WordPress Plugin
Directory, please try and let me know what is
I’m not a mind reader.
Use Google Libraries uses the following hooks (each with a priority of 1000).
Use Google Libraries compares it’s list of supported scripts to those
registered, and replaces the standard registrations
src with ones that
point to Google’s servers. Other attributes (like dependencies) are left
Use Google Libraries removes the
ver=x.y.z query string from the URL
used to load the requested library if it is going to load the library from
. Otherwise the URL is left unaltered. This both
improves the chances of the given URL already being cached, and prevents
script.aculo.us from including scripts multiple times.
If jQuery is enqued Use Google Libraries will inject a bit of
with the standard WordPress version.
Parts of this plugin (specificly, the dropping of the micro number,
which has since been removed for better caching performance) were
inspired by John Blackbourn’s
Google AJAX Libraries,
which has very similar goals to this plugin.
- add ability to enable/disable loading from Google for specific libraries
- using protocol-relative URLS with WordPress >= 3.5
- use WordPress provided
is_sslrather than custom check (only for
WordPress < 3.5)
- Detect if ‘jquery’ is a meta-script registration, and actual jQuery
is loaded as ‘jquery-core’ tag (WordPress 3.6 Beta).
- fix bug in
wp_remote_headto query that the replacement URL is actually
hosted by google. If it’s not, then the WordPress supplied version will be
- Using the Transient API to store the replacement URLS, rather than
recalculating and re-querying them every load.
- Added check for WordPress including non-standard versions of scripts (fixes
- Fixed incorrect case in HTTPS check.
- Reworked handling for cases where multiple js files are combined
into one on Google’s servers. In the past this has been mostly a
non-issue because the dependencies took care of it, but due to changes
in the latest jQuery UI this stopped working as expected.
- Updated jQuery UI to work with WordPress 3.1rc1
- Re-disable script concatenation. Seemed to break widget admin page.
- No longer disable script concatenation when using WordPress 3.0 or
- Attempt to detect when another plugin or theme has called
‘wp_register_script’ and/or ‘wp_enque_script’ before ‘init’ and work
- Limited debugging output when WP_DEBUG is enabled.
- Hopefully fix issue with plugin loading for some users
- Added Incompatible Plugins and Incompatible Themes sections
to the README
- more https detection
- inline jQuery.noConflict()
- fix previous fix (whoops!)
- Quick and dirty workaround for scriptaculous loading (thanks to
Gregory Lam for bringing it to my
- moved location of the Changelog section in the README
- Disables script concatenation in WordPress 2.8, since it seems to have
issues when some of the dependencies are outside of the concatenation.
- Persists flag to load scripts in the footer in WordPress 2.8
- It should detect when a page is loaded over https and load the libraries over https accordingly
- It no longer drops the micro version number from the url. The reasons for this are twofold:
- It ensures the version requested is the version received.
- Google’s servers set the expires header for 12 months for these
urls, as opposed to 1 hour. This allows clients to cache the file
for up to a year without needing to retrieve it again from Google’s
servers. If the version requested by your WordPress install
changes, so will the URL so there’s no worry that you’ll keep
loading an old version.