Step 1: Ensure browser compatibility by focusing on accessibility
The same techniques that make your site more accessible to search engines, such as static HTML versus fancy features like AJAX, often help your site's compatibility on various browsers and numerous browser versions. Simpler HTML is often more easily cross-compatible than the latest techniques.
Step 2: Consider validating your code
If your code passes validation, you've eliminated one potential issue in browser compatibility. With validated code, you won't need to rely on each browsers' error handling technique. There's a greater chance that your code will function across different browsers, and it's easier to debug potential problems.
Step 3: Check that it's usable (not just properly rendered)
Step 4: Straighten out the kinks
This step requires some trial and error, but there are several good places to help reduce the "trials" as your make your site cross-browser compatible. Doctype is an open source reference with test cases for cross-browser compatibility, as well as CSS tips and tricks.
For example, let's say you're wondering how to find the offset for an element on your page. You notice that your code works in Internet Explorer, but not Firefox and Safari. It turns out that certain browsers are a bit finicky when it comes to finding the offset—thankfully contributors to Doctype provide the code to work around the issue.
Step 5: Share your browser compatibility tips and resources!
We'd love to hear the steps you're taking to ensure your site works for the most visitors. We've written a more in-depth Help Center article on the topic which discusses such things as specifying a character encoding. If you have additional tips, please share. And, if you have browser compatibility questions regarding search, please ask!
Link -from Google Webmaster Central Blog
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