Best way to stress test a website [duplicate]

Question

Try http://loadimpact.com the best I have found so far, but no alternative to it I can find.

My suggestion is for you to do some automated tests first. Use selenium for it.

Then deploy selenium grid to test in multiple computers at the same time.

Although Selenium as an automated test tool will run quite fast, making a mini stress test. If you put the same automation running on a couple of computers on your network at the same time you'll be able to see how it behaves.

If you want to record response timings, they have a cool api you can use to write some scripts to run your automations.

Edit: Selenium is quite easy to use, and it does asserts to page contents if you want to test the contents. It also copies your movement through the page if you wish (this would be my suggestion) just navigate the page a lot, and then save it for automation. Avoid putting asserts so selenium might run faster.

JMeter would be one such tool. Can be a bit hard to learn and configure, but it's usually worth it.

The ab (apache bench) tool allows you to send many requests to a single page and you specify how many clients you want to be used and how many concurrent connection you want.

This may be the first step when developing a site. Just test some pages with a specific load. This way of benchmarking may have some problem, like caching being over used.

Later you may want a tool that simulate some concrete traffic and not for a single page. I don't have a refence handy on such tool yet.