Black-Box Testing: Definition, Types & Techniques
Black-box testing lets you analyze how something works without digging into the way it's built.
You might use the method to ensure that your website works perfectly before you launch it. Or you might schedule a black-box test at multiple points during the app development process.
Black-box testing has limits. Once you have the results, you'll need to unpack the code and find the right fixes. But if you perform regular, consistent black-box testing, you can make sure that your tools work both properly and consistently for your customers.
What Is Black-Box Testing?
Your team knows what your software, website, or app is supposed to do. As your team members work, they look for hiccups, glitches, or unexpected actions that could indicate a coding error.
You could use black-box testing to find:
- Omissions. Did you promise functionality that's missing?
- Errors. Does the interface work unexpectedly? Is the data source sound?
- Limits. Do certain inputs make the system crash or perform poorly?
A black-box testing team has no idea how you built the testing subject, so they can't give you suggestions to fix any problems they find. Their only job is to highlight items that need more investigation.
If you need input on coding problems, which could make repairs quicker, white-box testing or pen testing might be a better choice. People who work on these teams know all about the code beneath a product, and their tests ensure your product works as you designed it.
When Is Black-Box Testing Used?
On one day in May 2020, thousands of people tried to launch apps on their phones and experienced crashes instead. Facebook's coders were to blame. Black-box testing could have prevented this catastrophic problem.
Before you launch anything to the public, you should test it carefully and repeatedly. The work you do now could ensure that customers have less to complain about in the future.
If you're building software, you'll run black-box tests multiple times. Testing is part of the software testing life cycle (STLC), and you typically perform it during the following stages:
- Requirement: Software testers determine what elements of the product they can and can't test.
- Planning: Testers determine what sorts of tests will work best and how they will measure success.
- Analysis: Testers specify ideal test conditions.
- Design: They identify formal rules for each test.
- Implement: Testers create test cases.
- Execution: Tests begin, and testers log defects.
- Conclusion: Formal reports end the cycle.
Your product might go through this same process multiple times during development. Each test tells you a little more about what's working and what's broken.
Black-box testing might also make you less vulnerable to hackers. Some of your tests should involve trying to break past security limitations, and any successful breach indicates that you have more to do to keep your data safe. You might run this form of repeated testing throughout the lifecycle of your product, just to ensure that everything remains secure.