Tools for Debugging Web Pages

What tools do you use when you work with web pages? What do you use to disable styles, Java or Javascript, check if the HTML or CSS validates, check it for WCAG compliance, check the colour contrast or debug CSS and Javascript? Some of these things are directly supported in the modern browsers and for some you need an external tool. So here’s my small list of tools I’m used to. Maybe you will find some useful hints here and maybe you can give me some (-:

I usually use both Firefox and Opera. I like Opera because it’s fast. And more user-friendly in some respects. I like Firefox because I’m used to it and there are some plugins for which I haven’t found an equally functional counterpart in Opera. One of such plugins is Firebug. It really helps if you need to debug CSS or Javascript. Especially if the source code is chaotic :-)

For both Firefox and Opera (and even for IE 7) there’s a free tool called Web Developer Toolbar. They are not identical in different browsers (they are also developed by different people :-) but in general they are just toolbars with buttons like Validate HTML, Disable Images or View Javascript. They are useful also for everyday life, not just for webdesign.

Sometimes you need to see what is happening behind the scenes, i.e. what HTTP headers a server is sending. The Live HTTP Headers Firefox extension can help with this a lot. There’s also a similar HTTP Headers Opera widget but IMHO it’s a bit more difficult to use.

There are loads of useful tools out there. In general, you can find lots of accessibility checking tools on the Web Accessibility Initiative Homepage and a number of SEO analysis tools on the RankQuest Homepage. Apart from the usual W3C Validators there are two tools that I use quite frequently. First is the W3C Link Checker and the second is the JuicyStudio’s Colour Contrast Analyser Firefox extension. If you want a non-firefox colour contrast tool you can use AccessColor.

I work under Linux and don’t like switching to Windows. So in case I want to look at the page in IE I either use IEs4Linux or a virtual machine with Windows through VMWare.