1. Introduction

Ad hoc Testing is an informal and unstructured type of testing performed without any formal documentation, test plan, or test cases.
It focuses on finding defects randomly through unplanned, creative, and spontaneous testing efforts.

Definition:
Ad hoc Testing is a testing technique where testers try to break the system by performing random actions and using their intuition, domain knowledge, and experience — without following any predefined test cases.

The term “ad hoc” literally means “for this purpose only” — i.e., it is done on the spot to quickly identify potential issues.

2. Objective of Adhoc Testing

The main goal of Adhoc Testing is to:

• Uncover defects that may not be found using formal testing methods.
• Test the system from a user’s point of view in unexpected ways.
• Validate the system’s stability, robustness, and usability.
• Quickly verify functionality after minor changes or bug fixes.

🧠 In short: Adhoc Testing is used to “think out of the box” and catch hidden or overlooked bugs.

3. When to Use Adhoc Testing

Ad hoc Testing is particularly useful when:

• There is limited time for testing.
• Formal test cases don’t cover certain areas.
• A new build is deployed, and a quick sanity verification is needed.
• Exploratory or regression testing needs additional coverage.
• Testers want to validate fixes or simulate end-user behavior.

4. Example Scenarios

🛒 Example 1: E-commerce Website
A tester randomly:

• Adds an item to the cart, removes it, then re-adds it after refresh.
• Applies invalid discount coupons multiple times.
• Enter special characters in address fields.
• Changes browser tabs during payment.

💡 Outcome:
The tester finds that refreshing during payment causes session timeout issues — a defect missed in formal test cases.

💬 Example 2: Chat Application
A tester:

• Sends 100 emoji messages quickly.
• Opens multiple chat windows simultaneously.
• Test file upload with large and unsupported file formats.

💡 Outcome:
App crashes due to unhandled message queue overflow — caught only through ad hoc testing.