How can I see what my web site looks like in various browsers?
Short of actually having every different browser version installed, is there any tool or service that can provide a preview?
http://browsershots.org/ (online service).
http://www.browsera.com/ (online service, not free).
http://crossbrowsertesting.com/ (on-line service, not free).
http://www.multibrowserviewer.com/ (virtualized web browsers, not free).
http://www.browserseal.com/ (virtualized web browsers, not free).
Multi Browser vmWare Appliance:
LitmusApp is a new player in the field. Their current major value-add is e-mail client testing (33 clients, including mobile), but they also do "in the cloud" browser testing of up to 24 browsers. In fact, browser testing was their first product, and it's still available independently through the Alkaline tool.
I use Alkaline routinely. It's quite nice.
The best thing about it is: you don't have to own or install any of the browsers you want to test. They take care of all of that, and give you screenshots of the browser running on a real system in isolation. Myself being a terrible sysadmin person, this is ideal.
This is quite good: http://browsershots.org/
See how it looks on a range of browsers and resolutions. Needs to be on the web though.
Have the browsers local gives you more flexibility. If you have an interactive website where you need to click on several buttons to test, you cant verify this with an image.
MS also have (as part of the Expression toolkit) a product called SuperPreview, which allows you to work either side-by-side or overlaid with an interactive version of your site in all versions of IE and the latest version of Firefox.
It also includes access to a web service that show you what your site looks like in Safari on a Mac - this will generate an image of the output, but also uses a metadata file that allows you to see which parts of the markup generated which parts of the image, so it's still quite powerful.
This is one of the core reasons to develop on an Apple computer. Using VMWare Fusion or other emulation softwares, it is the only computer that you can legally install all of the major operating systems on.
Then you can test the actual browsers in the actual OSes, not reliant upon outside sources to do your dirty work for you, where you can use the native debugging tools to fix/diagnose any errors.
http://www.browsercam.com/ (online, not free) is another one.
Using a preview for the general design is good, but don't forget to test the behaviour of your site as well. This is especially usefull if your using a lot of hover, ajax or java-script effects, which you can't see on a picture.
I use VmWare with different virtual machines with the most important browsers installed seperately.
If you're using Windows 7 Ultimate I can refer you to a tutorial with Virtual PC and Xp Mode, which is a solution for running different IE versions on one host.
You may want to check out the thread on StackOverflow called: Testing a website on mobile browsers.
MogoTest is a very recent TechStars startup that does this well. It provides screenshots from different browsers and OSes, and validates your HTML & CSS, too.
I've used http://www.browserstack.com/ a few times, it works really well - surprised no-one's mentioned it yet.