Ad Hoc Testing: A Quick Guide to Finding Hidden Bugs
Most software testing tends to follow a defined plan, with test cases listed in written form. However, sometimes the quickest way to find bugs is to use the application without any scripts in front of you, basically like a real user would do. This is the essence of Ad Hoc Testing.
Ad Hoc Testing is an informal and mostly unstructured testing technique where you are relying purely on your brain and instincts instead of documentation. You just navigate through the application, try various things, and see what breaks. It is very flexible, very fast, and often discovers application issues that planned testing would never have identified.
This blog will guide you through everything you need to know about Ad Hoc Testing, including details of what it is, why it is important, and how to use it effectively.
What is Ad Hoc Testing?
Ad Hoc Testing is an unplanned, spontaneous testing process where the tester tries to break the application without any documented test cases. It is testing that is done with no planning or documentation, intending to find significant defects that could otherwise go undetected.
Ad hoc testing is unlike any other formal testing approach because it does not require a lot of documentation or planning. Ad hoc testing provides a framework to never consider what does not work; instead, it allows the tester to review the thoroughness of the software through non-sequential states of the tester's choosing.
Features of Ad Hoc Testing
Ad hoc testing focuses on finding bugs in your software without prewritten test cases. It can be less formal, more flexible, faster, riskier, and surprisingly effective. So, what makes it different?
1. Unplanned and Informal
Ad hoc testing will not have any documentation or prewritten test cases, and is generally conducted based on the tester's intuition and experience, often while conducting the testing.
2. Focuses on Finding Unexpected Bugs
Due to ad hoc testing not being limited to predetermined steps, it tends to discover bugs/defects that formal testing will not, especially edge cases and real-world examples of anticipated activity in the application.
3. Highly Exploratory
Testers will explore the application in the same way that a user would explore the application. Since testers can take all of these actions freely, they can familiarize themselves with the environment beyond the normal trial paths and attempt actions that would not normally be considered in a structured test case scope.
4. No Documentation Required
There were no requirements to prepare or maintain any sort of test plans or logged documentation before starting the testing effort. However, if any findings were determined in the testing session, tests may be documented later in order to file bugs or provide feedback.
5. Quick Setup, Faster Results
Ad hoc testing makes sense if there are no documented test cases created to support a test design before release, and there is very little time to prepare, or when testing newly implemented features into newly added applications.
6. Best Performed by Experienced Testers
The effectiveness of ad hoc testing is highly dependent on the knowledge, instinct, and understanding of the software of the tester.
Ad hoc testing shares many principles with exploratory testing, a structured, but flexible testing style that encourages creativity and learning in real time. If you'd like to learn more about how real-time, unscripted testing can improve effective software quality, check out Keploy’s blog post: “How Exploratory Testing Can Improve Software Quality.”
Importance of Ad Hoc Testing
The main benefit of Ad Hoc Testing is its flexibility and speed. There is no formal preparation needed, so testers can start testing the system as soon as a build is ready to be checked. This type of testing allows for the documentation of significant bugs that would not have been found using a formal test case, and it can take a very reasonable amount of time to complete.
This type of testing is particularly useful to do while still in the later stages of appearance of development process, and when formal test scripts cannot be written because time is short and you need to have some validation that major parts of the system have stability.
When to Use Ad Hoc Testing
Ad Hoc Testing is most useful when you need quick, flexible testing without spending time on detailed test cases or documentation. Here are some situations where it works best:
1. When a new feature is just added
When a new feature or functionality is added to an application, ad hoc testing is a good way to quickly test that it works as expected. Instead of waiting for formal test cases to be written, testers can now interact with the new feature and look for any errors.
2. After a bug has been fixed
When a bug that had been identified has been fixed, ad hoc testing can verify that the bug is gone. Testers can also test adjacent functionality and ensure that, in fixing the bug, nothing else is now broken; this is sometimes called regression testing.
3. When time is short before a release
In a fast-moving development cycle or just before a product release, there may not be time to execute the full suite of formal tests. In these instances, ad hoc testing provides a quick way to perform a last-minute check on key areas of the application.
4. When testers want to explore like a real user
There are times when the testers just want to use the application as a real user would. Ad hoc testing allows the tester to use the software and interact with it without restriction, trying out various paths, inputs, and combinations to see if anything "breaks." Ad hoc testing will frequently find problems that would not surface in the planned, scripted test cases.
Additionally, the power of ad hoc testing can be enhanced when used together with Keploy’s record-and-replay approach. Teams can record real user behaviors during ad hoc sessions to generate automated API test cases with Keploy. Later, the tests can be easily run through the CI/CD pipeline following Keploy’s GitHub Actions integration guide.
When Not to Use Ad Hoc Testing
Ad hoc testing is useful in many situations; however, there are times when ad hoc testing is likely not the best approach. These situations often involve more risk or a higher degree of quality requirements.
1. When testing critical or high-risk systems
Applications that deal with sensitive data (financial, medical, aviation) or safety systems will require very precise and traceable testing. In these cases, all testing will have the requirement to be planned, documented, and repeatable. Ad hoc testing is much too informal to be reasonable in this type of controlled environment and may miss significant checks.
2. When formal documentation is needed
If you require detailed test reports for auditing, regulatory compliance, or to allow your client to review the work you are performing, then ad hoc testing won't suffice as a standalone measure. Ad hoc testing is usually unstructured and rarely documented, so you won’t have the evidence or traceability needed for these processes.
3. When working under QA constraints
Some organizations/industries maintain formal quality assurance standards that they require adherence to, and all testing must follow defined processes. In these situations, ad hoc testing may be discouraged or even prohibited as it may not be in keeping with their required process.
Types of Ad Hoc Testing
Types of Ad Hoc Testing Ad hoc testing can be conducted in multiple ways, depending on how testers want to explore the application. The following are the most popular:
1. Buddy Testing
Buddy testing involves a developer and a tester working together on the same feature. One runs the tests while the other observes and gives feedback. This approach combines technical and user perspectives, making it effective and often faster at finding bugs early in the testing process.
2. Pair testing
Pair testing is like buddy testing but involves two testers. They explore the application together—either taking turns or sharing a screen—discussing their observations. This collaborative approach encourages brainstorming and helps uncover bugs that one tester might overlook.
3. Monkey Testing
Monkey testing is a random, unstructured form of ad hoc testing where testers input unpredictable data or actions to see how the app handles unexpected behavior. It's useful for checking stability and identifying crashes or unhandled errors.
Ad Hoc Testing in Practice: A Quick Demo
Let us take a basic web-based To-Do List application as an example. It allows users to add tasks, view them, and mark them as complete.
You open the application and see a text box, an Add button, and a list below.
Here is how you might begin your ad hoc testing session:
You enter a simple task like "Buy groceries" and click Add. The task appears in the list. This is expected behavior.
You then try entering a long string of characters, say 1000 letters, and hit Add. The application freezes. You have just discovered a performance issue related to input validation.
Next, you click the Add button twice in quick succession. The task gets added twice. This reveals a problem with button click handling.
You refresh the page and check if your tasks are still there. They are missing, which means the application is not saving data correctly.
This entire process takes only a few minutes, but already you have discovered multiple issues without any test plan. This is the true power of ad hoc testing.
How to Conduct Ad Hoc Testing
Although ad hoc testing is unstructured and does not have a written test case plan, a straightforward and thoughtful approach can establish a measure of effectiveness and efficiency. This is how you do that:
1. Understand the Application First
You will want to know what the application is (or what it is supposed to do) before you start. You do not need the entire specification, but an understanding of the key applications, functions, features, and blends of user flows and paths will allow you to test with more knowledge and understanding.
For example, you should know what typically happens when a user logs in, adds some items to a basket, and or submits a form.
2. Pick a Specific Area to Focus On
You should pick a single feature or module to test each time. For example, the login page, search functionality, payment process, or form submission etc. This will allow you to give your testing focus, but also to go through various parts of the application and not miss anything.
3. Use the System Like a Real User
You should try and use the application by "acting" like a real user. Click through the menus, enter standard user inputs, and do the things users do. Once you have gone through the motions, try to go one step further; do things that users might accidentally do, like send a form without filling in all the fields, for instance.
4. Try Unusual or Incorrect Inputs
Try peak or invalid data to see how the system responds. Write excessive text, special characters, empty fields, or numbers when text data is expected. This often reveals validation issues or unhandled crashes.
5. Experiment with Unexpected Actions
Do things that may not have been anticipated during development. Click a button more than expected, try multiple tabs to open the same page, or press the back and forward buttons in quick succession. This type of testing will reveal edge cases or unhandled errors.
6. Make Notes or Record the Screen
Your Screen Ad-hoc testing does not have formal documentation. But you should document your ad-hoc testing in some way so you can refer back to it and report issues to the developers that you found during ad-hoc testing. Keep notes, take screenshots, or use screen recording tools to capture bugs to make it easy to report later.
By following these simple steps, ad hoc testing becomes more focused and productive while still keeping its flexible and creative nature. Now, let’s see how a tool like Keploy helps us test our application without writing a single line of code.
How Keploy Helps You Test Your Application
In Adhoc testing, there’s typically minimal documentation or planning required, right? But what if you could test your application without even writing code? Sounds interesting, right? With Keploy, you can perform API testing, unit testing, and integration testing—all with zero code. Let’s dive into each of these in more detail:
Keploy API Testing:Keploy generates complete API workflow tests by observing real traffic to a deployed endpoint. These workflows are fully self-contained and don’t require human review — no test data setup, no reliance on mocks or external fixtures. The best part? You can try API testing locally. Plus, you can use the Keploy Chrome extension to record your API test cases.
Try it out here: app.keploy.io
To try Keploy Chrome Extension: Chrome webstore
Keploy Unit Testing:Keploy uses AI to auto-generate unit tests directly within GitHub PRs by analyzing code changes. Tests are suggested inline and validated before being surfaced — ensuring they build, pass, and add meaningful new coverage.
PR Agent: Connects directly to GitHub, analyzes code changes, and auto-suggests unit tests. It ensures any new code is covered with tests, providing instant AI feedback right within your PR, saving time and improving code quality. To try PR Agent use this link: Github marketplace
VS Code Extension: Brings Keploy’s test generation features into your editor. With just one click, you can generate, run, and view tests, making it easy to catch edge cases and debug faster without ever leaving VS Code. To try VS Code Extension use this link: Visual studio marketplace
Keploy Integration Testing:Keploy has built the world’s first eBPF-based network proxy that records API interactions as test cases and mocks them. These interactions are then replayed as full integration tests. Best of all, there are no code changes required for integration. To know more about: Integration Testing
Conclusion
Ad Hoc Testing is not intended to take the place of structured testing and is a key addition to testing that allows the tester to find defects that would not be discovered by structured test cases. When done in a targeted manner, ad hoc testing can result in quicker feedback, better product development, and ultimately a better user experience.
If you are looking for flexibility and speed in testing your application, you may want to use ad hoc testing when considering how to test your application. Just remember that ad hoc testing should be effective only when you balance it with structured testing when necessary.
FAQs
1. Is ad hoc testing the same as exploratory testing?
Not exactly! Exploratory testing is much more structured and often partially documented. Ad hoc testing is completely unstructured and spontaneous.
2. Can developers perform ad hoc testing?
Yes! Developers are actually the best suited to do quick ad hoc tests after they write some code, to see if it is functional.
3. How does Keploy actually help in reducing test maintenance?
Keploy captures real traffic and automatically creates test cases and mocks. This cuts down on manual work and keeps tests up-to-date as your services change.
4. Can ad hoc testing be automated?
Not really. Ad hoc testing is entirely reliant on human intuition, spontaneous actions, and creativity, whereas automation tools rely on structures. The point of ad hoc testing is to find unplanned problems through exploration in the moment.
5. Can ad hoc testing be applied within Agile development?
Yes! Ad hoc testing is especially compatible with Agile approaches. Agile teams typically need to be able to test quickly and flexibly during sprints, and ad hoc testing enables them to check new features or fixes quickly. Just make sure you're not using ad hoc testing as a substitute for your formal testing strategies.
