Originally posted here.

In a two-for-one Ask a Flooder, I answer two questions: What is the difference between performance testing and load testing and in which situations is performance testing a better option than load testing?

Transcript:

Hi again, it’s Nicole back for another Ask a Flooder. And this time, the question from one of our customers is:

What is the difference between performance testing and load testing?

Now, this is really a matter of semantics, and it kind of depends on whom you ask, but in general, performance is how quickly an application responds. So when you’re doing performance testing, you’re doing one of two things: there’s front-end performance, and then there’s back-end performance.

In front-end performance, you’re looking at things like how quickly does the application render for the customer on the client-side. It’s how fast something renders on the screen, so it’s how page resources can be rearranged or optimized so that the experience is a lot faster for the end customer. So the focus is on the client-side on the end user’s actual device.

On the back-end performance side, you’re looking at the server. How quickly does the server send a response to a request that’s sent by the browser?

So those are really two different things because back-end performance really looks at everything outside - everything beyond - the device of the customer. Both kinds of performance testing are important. A solid, holistic performance testing strategy will incorporate both front-end and back-end performance.

There are different types of back-end performance testing. You might have heard of load testing, stress testing, volume testing. At Flood, we kind of refer to all of those under the bracket of load testing. They do have some semantic differences between them, but in general, we talk about load testing to refer to simulating traffic against an application server to see how that server responds.

Now the type of the testing that you want to do will also affect the kind of performance testing tool that you choose. For instance, a tool like Flood Element can do both front-end and back-end testing, but a tool like JMeter is only going to be useful for the back-end performance testing. So you need to choose your test according to the testing type that you’d like to carry out.

This customer also had a follow-up question:

In which situations is performance testing a better option than load testing?

And one answer to this is when front-end performance is required. So if what you’re after is trying to speed up how quickly your application renders on a mobile device, for instance, you might be better off looking at tools like GTMetrix or WebPageTest in order to measure and improve that side of it.

I really want to stress here that neither front-end performance nor back-end performance is better than the other. If you’re asking me which type of testing you should do, my answer would be both. Till next time, happy flooding!