javascript - Where do you include the jQuery library from? Google JSAPI? CDN?

Question

There are a few ways to include jQuery and jQuery UI and I'm wondering what people are using?

• Google JSAPI
• jQuery's site
• your own site/server
• another CDN

I have recently been using Google JSAPI, but have found that it takes a long time to setup an SSL connection or even only to resolve google.com. I have been using the following for Google:

<script src="https://www.google.com/jsapi"></script>
<script>
google.load('jquery', '1.3.1');
</script>

I like the idea of using Google so it's cached when visiting other sites and to save bandwidth from our server, but if it keeps being the slow portion of the site, I may change the include.

What do you use? Have you had any issues?

Edit: Just visited jQuery's site and they use the following method:

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>

Edit2: Here's how I've been including jQuery without any problems for the last year:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>

The difference is the removal of http:. By removing this, you don't need to worry about switching between http and https.

Answer 1

Without a doubt I choose to have JQuery served by Google API servers. I didn't go with the jsapi method since I don't leverage any other Google API's, however if that ever changed then I would consider it...

First: The Google api servers are distributed across the world instead of my single server location: Closer servers usually means faster response times for the visitor.

Second: Many people choose to have JQuery hosted on Google, so when a visitor comes to my site they may already have the JQuery script in their local cache. Pre-cached content usually means faster load times for the visitor.

Third: My web hosting company charges me for the bandwidth used. No sense consuming 18k per user session if the visitor can get the same file elsewhere.

I understand that I place a portion of trust on Google to serve the correct script file, and to be online and available. Up to this point I haven't been disappointed with using Google and will continue this configuration until it makes sense not to.

One thing worth pointing out... If you have a mixture of secure and insecure pages on your site you might want to dynamically change the Google source to avoid the usual warning you see when loading insecure content in a secure page:

Here's what I came up with:

<script type="text/javascript">
    document.write([
        "<script src='",
        ("https:" == document.location.protocol) ? "https://" : "http://",
        "ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js' type='text/javascript'></script>" 
    ].join(''));
</script>

UPDATE 9/8/2010 - Some suggestions have been made to reduce the complexity of the code by removing the HTTP and HTTPS and simply use the following syntax:

<script type="text/javascript">
    document.write("<script src='//ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js' type='text/javascript'></script>");
</script>

In addition you could also change the url to reflect the jQuery major number if you wanted to make sure that the latest Major version of the jQuery libraries were loaded:

<script type="text/javascript">
    document.write("<script src='//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js' type='text/javascript'></script>");
</script>

Finally, if you don't want to use Google and would prefer jQuery you could use the following source path (keep in mind that jQuery doesn't support SSL connections):

<script type="text/javascript">
    document.write("<script src='http://code.jquery.com/jquery-latest.min.js' type='text/javascript'></script>");
</script>