Testing is one of the key processes in application development, used to provide quality and reliability of applications. It has been divided into manual testing and automation testing, and both have several pros and cons.

This blog deals with the difference between manual and automation testing, their key features, pros and cons, and when to use which approach.

What is Manual Testing?

Manual testing is the execution of test cases manually. QA tester performs a predefined test plan to ensure that an application performs what it should.

Key Features of Manual Testing:

• Testers execute test cases without scripts or tools.
• Requires human intervention to confirm defects.
• Utilized for exploratory, usability, and ad-hoc testing.
• Best suited for UI/UX testing and scenarios that require human instinct.
• Tedious but excellent for small projects.

Example 

Suppose an e-commerce website introduces a new checkout procedure. The steps below would be executed by a manual tester:

• Add a product to the cart.
• Checkout.
• Add billing details.
• Add payment option and finalize the order.
• Verify order confirmation.

A manual tester would validate if the process executes seamlessly, identifying any UI discrepancies, usability issues, or broken flows.

What is Automation Testing?

Automation testing, in simple terms, is the process of executing test cases by using scripts and tools automatically without manual intervention. It is ideally suitable for regression testing, load testing, and repetitive work.

Important Features of Automation Testing:

• Scripts execute the test cases automatically.
• Supports using testing frameworks and tools like Selenium, JUnit, TestNG, etc.
• Faster than manual testing for large projects.
• Reduces human mistakes and makes it effective.
• Expensive in terms of initial setup but gives long-term benefits.

Example

For checkout in e-commerce, a test script would programmatically:

• Open the site.
• Add an item to the cart.
• Proceed to checkout and enter test data.
• Assertion-check the checkout.
• Generate a test report automatically.

This time is saved during testing on different browsers and environments.

Difference Between Manual Testing and Automated Testing

Key Features of Manual Testing

• Testers are able to explore the application without being bound by scripted scripts.
• Time-Consuming: Iterative tests require manual effort.
• Most appropriate for UI and Usability Testing: Human nature can detect design and usability issues.
• No Coding Required: Suitable for teams with no programming expertise.
• Higher Chance of Human Error: In contrast to automation, it depends on the observation level of the tester.

Key Characteristics of Automated Testing

• Fast Execution: Automation saves considerable time for test execution.
• Reusability: Test scripts can be reused once created with various builds.
• High Accuracy: Includes human errors while executing tests.
• Best for Repetitive Tests: Ideal for performance and regression testing.
• Initial Setup Complexity: Requires tool and scripting knowledge setup.

When to Execute Manual Testing?

• Exploratory Testing: When testing a new application with no prior test cases.
• Usability Testing: To verify that the software is easy to use.
• Ad-hoc Testing: When executing speedy, casual tests.
• Small-Scale Projects: Where setting up automation is not needed.
• Frequent UI Changes: If the application is being constantly updated with UI changes, maintaining the automation scripts will be costly.

When to Execute Automation Testing?

• Regression Testing: Running tests again and again after updates.
•  Performance and Load Testing: Checking the performance of the system with high loads.
•  Data-Driven Testing: Running the same test using varying datasets.
• Cross-Browser Testing: Checking compatibility in different browsers.
• Repetitive and Time-Consuming Tests: Reducing manual effort for repeat tests.

Manual vs. Automated Testing example

Let’s assume an e-commerce website has a new feature of discount.

Manual Testing Approach:

• QA testers check manually if the discount is being applied correctly.
• They check edge cases, i.e., using several discounts or removing items from the cart.
• They check for usability, ensuring the discount notice is clear to users.

Automation Testing Approach:

• Automated scripts add several products to the cart and verify if the discount is correctly calculated.
• The script runs on multiple browsers and devices to ensure it is cross-platform compatible.
• A performance test checks if the discount calculation slows down order processing.

Manual Testing Tools:

• JIRA – Test case management and defect tracking
• TestRail – Test management and reporting
• HP ALM (Application Lifecycle Management) – Test planning and execution
• qTest – Agile test management
• Bugzilla – Bug tracking and reporting
• Mantis – Lightweight bug tracking tool
• Zephyr – Test case management (JIRA integration)
• Xray – Test management for JIRA
• Postman – API testing (can be used for both manual and automation)
• Fiddler – Network debugging tool

Automation Testing Tools:

Functional UI Automation:

• Selenium – Web application automation (Java, Python, etc.)
• Cypress – Modern JavaScript-based test automation
• Playwright – Cross-browser UI automation
• Appium – Mobile app automation (iOS, Android)
• TestComplete – GUI test automation
• Ranorex – Low-code UI testing
• Katalon Studio – Built-in automation framework

API Testing Automation:

• Postman (Newman for automation)
• REST Assured (Java-based API automation)
• SoapUI – Web service testing
• Karate – API test automation

Performance & Load Testing:

• JMeter – Load and performance testing
• LoadRunner – Enterprise-level performance testing
• Gatling – Performance testing for DevOps

CI/CD & DevOps Integration:

• Jenkins – CI/CD pipeline integration
• GitHub Actions – Automated testing in CI/CD
• Azure DevOps – Test automation and deployment
• CircleCI – Continuous integration
• TravisCI – Cloud-based CI

Pros & Cons

Manual Testing

Advantages:

• Ideal for exploratory and ad-hoc testing.
• No need for scripting or programming knowledge.
• Ideally suited for experience, usability, and UI testing.
• Easy to customize to small changes in software.

Disadvantages:

• Time-consuming and manual-intensive.
• Prone to human errors.
• Difficult to scale to big applications.
• Not efficient for regression and performance testing.

Automated Testing

Advantages:

• Shorter run times for big test sets.
• More reliable and consistent than manual testing.
• Cost-saving in the long run.
• Parallel and cross-browser enabled.

Disadvantages:

• Scripting and tool expertise required.
• High initial setup and tool expense.
• Not efficient for quick exploratory testing.
• Effort required to keep the script up to date.

Conclusion

Manual testing and automation testing both play critical roles in guaranteeing software quality.

Manual testing is best suited for exploratory, UI, and usability testing where human instinct is involved. Automation testing is best suited for regression, performance, and time-consuming repeated tests that are error-prone.

The most suitable method depends on the project requirements, budget, and test goals. The software development best practice is usually achieved through the implementation of a combination of both techniques in a hybrid method. By understanding how manual testing and automation testing are different from one another, QA teams can plan an ideal test strategy, which results in better quality software and a greater user experience.