ith so many types, teams new to software testing often struggle to know what they actually need for their situation. The reality is, different teams need different combinations. A small startup building a web app has different testing needs than a healthcare company building regulated medical software. A team of three needs different approaches than a team of thirty.

This guide explains the main types of software testing – what each does, when it's useful, and how to figure out which ones fit your situation.

New to testing? It might be worth checking out our overview of testing basics, first.

What is software testing?

Ask ten people what software testing is and you'll get ten different answers. But essentially, software testing is about discovering what state your product is in so stakeholders can make informed decisions. You're fundamentally answering two questions – "does this work?" and "are we ready to launch?"

Testing approaches

Different testing types represent different strategies for organizing your work. Most teams use several.

Exploratory testing

Testers investigate the product however they think best, inventing tests as they go and reacting to what they discover. It’s about testers using judgment to hunt for problems, not following scripts.

Exploratory testing is usually the most effective kind of manual testing. Testers follow hunches, notice patterns and dig into suspicious behavior.

Regression testing

Checking that previously-fixed bugs stay fixed and working features keep working. Every time you fix a significant bug, add a test to catch it if it resurfaces.

Sanity testing

A quick check that basic functionality works before deeper testing. If users can't log in or the main page won't load, there's no point testing advanced features.

This is really just about using your common sense and checking the obvious things first.

Functional testing types

Functional testing verifies your software's features work correctly – the basic "does it do what it's supposed to do?" testing.

System testing

Testing your complete product as users would actually use it. You're verifying the entire system works correctly in realistic conditions. Most testing is system testing even if teams don't call it that.

User acceptance testing (UAT)

Getting actual users or clients to verify the software meets their needs before you ship. Real users interact differently than your team does, use different environments and have different expectations. UAT catches issues internal testing misses.

Unit testing

Developers write automated tests for individual pieces of code to verify they work correctly. These tests catch bugs early but only check isolated pieces, not how they work together or how the complete product behaves. Unit tests complement but don't replace testing the whole product.

Integration testing

Testing that different parts of your software work together properly – checking connections between services, APIs, or third-party tools. Most teams already do this as part of normal testing. If you're testing your product the way users actually use it, you're checking how parts integrate. Just make sure your testing covers connections between different parts of your system.

Non-functional testing types

Non-functional testing checks qualities beyond whether it works, like whether your software is fast enough, secure enough, or easy enough to use.

Performance testing checks if your software is fast enough and stays stable under normal use.

Load and stress testing checks if your system can handle lots of users at once and finds the point where it breaks down.

Security testing looks for ways attackers could break in, from basic checks like encrypted passwords to advanced attempts at hacking the system.

Usability testing checks if people can use your software. Watch users try to complete tasks and note where they get stuck or confused.

Which testing types does your team need?

Testing types aren't a menu where you order everything. Instead, you just need to choose what will help you solve your actual problems.

Every team needs:

• Basic functional testing (does it work?)
• Exploratory testing (human bug hunting)
• Regression checks (does it stay working?)

Add when relevant:

• Automation for repetitive checks
• Performance testing if speed matters
• Security testing for sensitive data
• UAT if delivering to clients

Consider skipping:

• Formal methodologies for small teams
• Extensive documentation nobody reads
• Any testing type because "everyone does it"

The goal isn't comprehensive testing coverage. It's catching problems before your users do.

Getting started with software testing

Pick three features users care about most and make a simple checklist of what needs checking. Then work through it, write down what broke and fix it. That's testing. Everything else builds from there.

Want more practical testing advice? Subscribe to get straightforward tips on all things testing sent straight to your inbox.

If you liked this article, consider sharing