esting is interacting with your software, trying different things, and seeing what works and what doesn't. The goal is finding problems early when they're cheap and easy to fix, rather than after you've shipped to customers. This guide covers the essential testing concepts you need to get started.

We'll walk through what testing actually is and why it matters, the main types of testing worth knowing about, and practical steps for starting testing without formal processes or expensive tools. You'll learn what makes good testing, common mistakes to avoid, and how to keep things simple while still catching bugs before they reach users.

If you're new to testing, it can feel overwhelming. There's loads of terminology, different types of testing, and tools claiming you need them – but most of it is unnecessary.

What is software testing?

Testing is discovering as much as possible about your product so you can decide what to do next. It's asking "are we ready to launch yet?" and having a real answer. Good testing finds bugs before users do. It verifies features work as intended, checks edge cases that might break things, and crucially, it gives you confidence about what you're shipping.

Testing happens throughout development, not just at the end. The earlier you find issues, the easier and cheaper they are to fix.

You can read more about what software testing is in this blog.

Do you really need testing?

Yes. Even small products benefit from basic testing.

Without testing, you're gambling that everything works. You'll ship bugs and users will hit them, which can be embarrassing and cost you customers. You'll spend a lot of time firefighting instead of building new features. Testing doesn't have to mean formal processes or expensive tools, though. It can be as simple as clicking through your product before you ship, trying different inputs, and checking things work.

Three basics of testing

Strip away all the jargon, and testing really comes down to three simple ideas: what you're testing, when you tested it, and what happened. Everything else is just different ways of organizing or describing these basics. Here's what actually matters.

Test cases
A test case is just an instruction for what to test. It might be a simple prompt like "check login works" or a detailed list of steps to follow. Keep test cases as simple as your situation allows. Detailed formal test cases have their place, but most teams benefit from shorter, simpler prompts.

Test runs
A test run is one pass through your tests. You might do multiple test runs - testing on different browsers, testing after each code change, or having different people test the same thing.

Pass/fail
The simplest way to record what happened. For each test, did it pass or fail? Mark it green or red. This gives you a quick visual overview of what's working and what isn't.

What are the main types of testing?

Testing has lots of different types and names, and they often overlap. Don't let that intimidate you. Most teams use just a handful of these, and you don't need to treat them as strict categories. Here are a few of the main types:

Manual testing

A human interacts with your software – clicking, typing, observing what happens. This is the most practical form of testing. Here’s how to get started.

Automated testing

Testing performed by scripts or programs rather than humans. Automated tests run quickly and repeatedly, making them ideal for checking the same things over and over – like verifying login still works after code changes or that calculations remain accurate across builds.

Exploratory testing

Testing where you're free to explore the product, inventing tests as you go and reacting to what you find. This is easily the best kind of manual testing. Get to grips with exploratory testing here.

Functional testing

Checking if features work as intended. Does the login accept valid passwords? Does the shopping cart calculate totals correctly? Most testing is functional testing, even if teams don't call it that.

Regression testing

Making sure previously fixed bugs stay fixed. Every time you find and fix a significant bug, add a check for it. That way you'll catch it if it comes back. Regression testing can be manual or automated.

We talk in greater details about the various types of testing on this page.

How do you start testing?

Start simple and don't worry about formal processes or tools yet.

1. Make a list of what needs testing

Write down the main features or areas of your product. Keep it simple – bullet points work fine. This becomes your testing checklist.

2. Work through your list

Go through each item. Try it. See if it works. Note anything that seems broken or weird. Don't overthink this. Just interact with your product like a user would and pay attention to what happens.

3. Try edge cases

Edge cases are unusual scenarios that might break things. Maximum values. Empty inputs. Weird combinations. These often reveal bugs. Focus on edge cases that could realistically happen and would matter if they failed.

4. Keep notes

Record what you tested, what worked, and what didn't. This doesn't need to be formal. Simple notes are fine. Good notes help you remember what you've covered and make it easier to report issues to whoever needs to fix them.

5. Test regularly

Don't save all the testing for the end. Test as you build, before you ship and after you ship. Regular testing catches issues early when they're easiest to fix.

How much testing is enough?

There's no magic number. It depends on your product, your users, and what's at stake if something breaks. A good rule: test enough that you're confident about shipping. If you expect users to find major bugs, you need to test more.

Focus testing on areas that matter most. Not everything deserves equal attention. Think about what would cause the most damage if it broke – that's usually payment processing, data handling, and core workflows. Test high-use features more than rarely-used ones, and test things that change more than things that don't.

What tools do you need?

You don't need special tools to start testing. A text file or spreadsheet works fine for simple products. As testing grows, dedicated tools help – test management tools organize your tests and track results.

Choose tools that match your needs. Don't adopt complex tools because you think you should. Many teams over-tool and waste time managing their tools instead of doing the actual testing.

Common testing mistakes to avoid

Most teams make the same testing mistakes early on. Some waste a bit of time, whereas these listed below waste a lot (which is why it’s worth knowing about them beforehand!).

• Waiting until the end to test. Test throughout development because finding bugs late is expensive and stressful.

• Only testing the happy path. Things break at the edges. Test error conditions, edge cases, and unusual inputs.

• Testing your assumptions. Test what users will actually do, not what you think they'll do. Users are creative at breaking things.

• Making testing too formal. Rigid processes slow you down, so keep testing as lightweight as possible while still being effective.

• Thinking automation replaces manual testing. Automation is powerful but limited – you need both. Read our guide on manual vs automated testing for more on this.

Getting better at testing

Testing is a skill that improves with practice. The more you test, the better you get at spotting potential issues. Remember to stick to the basics and keep your testing simple and focused on finding real issues. Don't get caught up in terminology or formal processes unless they help you ship better software. Want more testing insight? Subscribe to our emails.

If you liked this article, consider sharing