Have you ever found a bug while just playing around with an app? In software testing, you don’t always need to fully prepare scripts to test a simple case. That's the power of unplanned testing. This is where two valuable methods come in: ad-hoc testing and exploratory testing.
While ad-hoc and exploratory testing might seem similar, they are not the same. This article will explain the key differences, helping you understand when to use each approach to find more bugs and deliver a better product.
1. What They Are
Ad-Hoc Testing
Ad-hoc testing is an unplanned, continuous way of testing. It's done without any written documents, test cases, or plans. The main goal is to find bugs quickly by randomly trying things out. This type of testing relies entirely on the tester's experience and creativity.
For example, you are tasked with testing the login page. Your main goal here is to find any possible bugs on this page, so you don’t list out any test cases and test steps to do it. You just click randomly on any button to see if any bugs appear.
Exploratory Testing
Exploratory testing is also a flexible and adaptive approach to testing, but in a more intentional way. It does not require a detailed script to execute, but it at least has an objective to follow. The testers learn about the app, create tests, and run them all at the same time. It's not random clicking. Testers apply their knowledge and intuition to investigate different scenarios aligned with the objectives, and adapt their next steps based on what they discover.
In the same example, you are also tasked with testing the login page. But now you have defined your goal to ensure that the login flow can function properly. Although you don’t need test scripts and specific test steps, you will still have some general scenarios, like what happens when you use an incorrect password, leave a field blank, or try to log in with an email instead of a username. You're not just clicking randomly; you are exploring based on a specific, focused purpose.
2. What they have in common
Ad-hoc and exploratory testing share key traits: both are unscripted and do not rely on pre-written test cases or formal procedures. They depend on the tester’s skills, knowledge, and experience. By stimulating user behaviors, they are effective at uncovering bugs that formal testing might miss. This sets them apart from formal testing, which follows detailed, documented test cases and focuses strictly on predefined requirements.
3. How is Exploratory Testing Different from Ad-hoc Testing
Goal
Ad-hoc testing only has one main goal: to find as many bugs as possible, as fast as you can. It is a quick double-check step for defects that could impact user experience and ensure the stability of the feature.
On the other hand, Exploratory testing goals focus on two equal parts: to continuously learn about the app and to find new bugs in a specific area. Exploring the app is the foundation for effective testing. By actively exploring and understanding how the system works, you can find new and more complex bugs that a pre-written test might miss. The goal of finding new bugs is the ultimate outcome of this process. It's the tangible result that proves the value of the exploration. Therefore, you can’t achieve one goal without the other; they are two interconnected parts of a thorough process.
Planning
One of the main differences between ad-hoc and exploratory testing is planning. As the main purpose of Ad-hoc is to find as many bugs as possible, you won’t spend time on planning exactly what to do. You simply receive the requirements and try different actions purely based on your experience to see what issues may happen.
Exploratory testing, while also flexible and unscripted, is guided by a clear objective. You do not base your testing on formal test steps or detailed scripts, but will have some intentions in mind. These are from your experience and what you have explored about the features to uncover possible defects.
Approach
When it comes to the testing approach, ad-hoc testing is a random and disorganized process. With ad-hoc, “click matters per second”. The more clicks are conducted, the more likely a new bug is found. You see every random click as an equal opportunity to find a bug. Therefore, your testing results are also becoming unpredictable. Sometimes, you just need a few clicks to find a critical bug, while in some cases, it takes you hours with no valuable findings.
Exploratory testing is much more purposeful. You don’t need to prepare a detailed plan to tell you what you need to do at each step, but you need a “thinking process”. A test charter is often used to briefly define your test scope and goals for the sessions. With this guidance, you actively learn about the system, form intentions from observations, decide your next moves, and uncover deeper issues. It creates a “chain of thoughts” through your testing process, removing the bias and randomness of the ad-hoc method.
Documentation
Ad-hoc testing has no documentation. Test data in the ad-hoc test session is not inheritable. For instance, you click on the same “login button” every time you want to check a bug on the sign-in page to find a common bug. This button does not have any defects this time, but that doesn’t mean that it will not have any conflicts with the software after updates. That’s why you would rather conduct more clicking attempts, rather than record each single click.
Conversely, exploratory testing is more about continuously exploring and testing. Using the same example, you can scope down your test on the login method( via Email on sessions 1, via Google on session 2, etc), to explore how your software operates and ensure all login gates function properly. Thus, “documenting does matter”. It shows the cause and effect of your series of actions. Documenting your test provides evidence of discovered defects and helps reproduce bugs based on the sequence of steps you have conducted, linking with the results. Documentation also helps you to determine whether to focus on other re-run sessions, thus ensuring sufficient test coverage.
Scope of Testing
The scope of ad-hoc testing is unlimited. Although you can apply your experience and focus on a particular part that is usually buggy, there are no official documents to narrow your test scope. You are free to test any part of the app you want. This approach can be great for finding obvious bugs in unexpected places that might have been overlooked in a formal test plan.
In contrast, exploratory testing is focused. You are guided by a specific mission, which allows for a deeper, more detailed investigation, making it easier to uncover hidden or complex issues that might be missed by a quick, random test.
Time & Frequency
Ad-hoc testing is a one-time activity. It's not part of a regular schedule, but rather a quick reaction, often performed to check if the overall software is still stable after updates or changes. An ad-hoc session should be very short, typically lasting no more than 15 to 30 minutes. The goal is to quickly find any obvious bugs before a more formal testing process begins. A longer session would get you lost in unnecessary details.
Exploratory testing is a more regular and continuous part of the development cycle. It's a planned activity that helps to continuously find bugs and learn about the system over time. Exploratory sessions are usually performed in focused, time-boxed periods of 60 to 120 minutes. The goal of a time-boxed session is to maintain focus and allow enough time for a deep investigation without leading to prolonged sessions. You don’t need to execute all possible scenarios the first time, just focus on the initial scope and put the rest to later sessions.
Knowledge requirement
Ad-hoc testing requires minimal prior knowledge of the system. You can jump in and find obvious, easy-to-trigger bugs just by clicking around, making it a great option for someone new to the software.
Contrastingly, exploratory testing requires a much deeper understanding of the system and its business context. You have to apply your knowledge and experience to form a mission, anticipate potential issues, and adapt your testing based on what you have learned. This allows you to uncover complex or hidden defects that a new or less-experienced person might miss.
4. When Should They Be Used
When choosing the right testing method, the decision comes down to a trade-off between speed and thoroughness. The choice between ad-hoc and exploratory testing is not about which is better, but which is the smarter tool for the job.
Ad-hoc testing is a reactive, short-term solution for finding bugs efficiently when time or resources are limited. It's best used as a quick and informal check, like a small change or update. The primary goal is to find obvious, surface-level bugs that could have a big impact. In essence, ad-hoc testing prioritizes speed over comprehensive coverage, making it ideal in a low-risk context. In the software testing life cycle, ad-hoc testing is often done late in the development cycle for quick verification and to ensure that no critical bug affects the formal testing phases.
Meanwhile, Exploratory testing should be used when you need to investigate complex or new features. It’s especially useful when requirements are not fully defined to conduct formal testing, or in a high-risk context where you want to gather insights for later structured tests. Essentially, exploratory testing can be used throughout the test process whenever you need a deeper, flexible look at the system to catch issues that standard or scripted tests might miss.
Discover how to apply Ad-hoc and Exploratory testing in Jira with our video: Ad-hoc testing vs. Exploratory Testing | How to apply both in Jira Testing Process?
Final Thoughts
Neither ad-hoc nor exploratory testing is better than the other; they are just different tools for different jobs. Ad-hoc testing is like a quick, random search, using speed and intuition to find easy bugs. Exploratory testing is more like a detective's work, where the tester's knowledge is used to find deeper, more hidden issues. By understanding the unique strengths of each, you can improve your testing and make sure your product is as bug-free as possible.
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