Testing your website across multiple browsers is essential but painful. Here's a toolkit to make it easier.
Virtual Machines (The Proper Solution)
The most reliable approach is running actual browsers in VMs. Microsoft offers free Windows VMs with IE6/7/8 at http://www.microsoft.com/downloads/
Browser Screenshots as a Service
- Browsershots — http://browsershots.org/
Upload your URL and get screenshots across 60+ browser/OS combinations for free. Slow (queue) but comprehensive. - BrowserStack — http://www.browserstack.com/
Live interactive testing on real browsers. Paid service but invaluable for debugging IE quirks. - CrossBrowserTesting — http://crossbrowsertesting.com/
Similar to BrowserStack, good for automated screenshot workflows.
IE-Specific Tools
- IE Tester — http://www.my-debugbar.com/wiki/IETester/HomePage — Simulates IE5.5 through IE8 in tabs on one machine
- Multiple IE — http://tredosoft.com/Multiple_IE — Install multiple IE versions side-by-side (IE3–IE6)
Firefox Developer Tools
- Firebug — http://getfirebug.com/ — The essential inspector/debugger
- Web Developer Toolbar — http://chrispederick.com/work/web-developer/
Chrome / Safari
Both have built-in developer tools (Ctrl+Shift+I / F12). Chrome's DevTools are excellent for timeline analysis and network inspection.
Quick Tip
In 2009, the most common IE bugs are margin doubling on floats, hasLayout issues, and z-index problems with positioned elements. Always test in IE6, IE7, and Firefox 3 as a minimum.