How to Test a New Feature: Automation or Manually

Anushree Chatterjee

Ever find yourself overwhelmed with “where to start testing” when a new feature drops in your lap? Even if you have some time on your hands before the feature goes live, the difficulty arises when you need to figure out whether you should test it manually or automate it ASAP. While there’s no one-size-fits-all approach to this dilemma, there are ways you can come to a decision in a calculated and systematic way.

Key Takeaways

Feature testing ensures a new feature works correctly and meets quality standards. It includes planning, executing tests, finding bugs, and verifying fixes.
Manual testing allows testers to explore features like real users and catch usability flaws. It’s ideal during the early stages, when design and behavior are still evolving. Use it for early exploration, ad-hoc testing, and assessing complex or subjective features. It’s quick to start, flexible, and offers fast human feedback loops.
Automation uses scripts to run tests faster, more consistently, and across environments. It’s perfect for regression, load, and repetitive functional testing.
Base your decision on the feature’s complexity, maturity, risk, and business value. Also factor in your team’s skills, tools, timeline, and testing goals. Start with manual testing for exploration, then automate stable, critical flows. This balanced approach ensures speed, quality, and deeper coverage.

Let’s learn how to make that possible.

What does Feature Testing Entail?

Features get added to software applications regularly. While this is great, you’d want to make sure that these new additions are healthy, that is, they are free of bugs and other issues. That is what feature testing helps with. It is a way for you to make sure that the feature in question is of high quality.

Here’s an overview of how it generally works:

Understanding the Feature: Before testing, you need to know what the feature is meant to do. For example, if the new feature is a “Save” button, you want to make sure that you understand what impact that button has on the application.
Creating Test Cases: Test cases are like a list of things to check. For the “Save” button, test cases might include:
- Does it save your document when you click it?
- Does it still work if you’re connected to the internet or if your connection drops?
Running the Tests: Once you know what to check, testers use different methods to try out the feature in different scenarios. They will click the button, type text into a form, or use the feature in various ways to see if it works.
Identifying Problems: If the feature doesn’t work right – maybe the button doesn’t save the work, or it crashes the app – this is called a “bug”. Feature testing helps spot these problems so developers can fix them.
Checking for Edge Cases: Testers also check for rare or unusual situations, like pressing the button multiple times in a row, or using very large files. This helps make sure the feature can handle anything a user might throw at it.
Verifying Fixes: After developers fix any bugs, the testers check again to make sure the fix works and nothing else got broken in the process.

You can carry out feature testing manually or through automated testing. While both are helpful in their own way, the confusion arises when you have to pick which one to go for. Let’s look at both of these approaches before we decide which one works best.

Understanding Manual Testing for New Features

When a new feature comes to life, our first instinct is often to jump in and play around with it. That’s essentially what manual testing is all about. It’s when human testers directly interact with the software, clicking buttons, typing in fields, and exploring every nook and cranny to see how it behaves. We’re not using any special scripts or tools; it’s just hands-on, real-world interaction.

When Manual Testing Shines

Early-Stage Exploration & Usability: Imagine you’re building a brand-new car. Before you automate crash tests, you’d want someone to sit in it, feel the steering wheel, and try to open the doors. Manual testing is perfect for this initial “feel” – checking if the feature flows logically, if the buttons are where users expect them, and if the overall experience makes sense. It’s about understanding how a real person would use it and identifying any design quirks right off the bat.
Ad-hoc/Exploratory Testing: This is where testers really get to be detectives. Instead of following a strict script, they go off-road to try unexpected actions and combinations. This kind of “what if?” thinking often uncovers hidden bugs or unforeseen issues that a pre-programmed test might miss. It’s about human intuition and creativity in finding problems.
Complex Scenarios and Human Intuition: Some features involve really intricate user journeys or require a subjective judgment call. Think about testing a new image editor – how do you automate whether a filter “looks good”? Manual testing excels here because it uses human perception and decision-making for those nuanced interactions.
Cost-Effective for Initial Tests: Getting started with manual testing is usually pretty quick and doesn’t require a big upfront investment in specialized tools or complex setups. You can start testing almost immediately, which makes it a good choice for initial checks.
Rapid Feedback Loop: When a manual tester finds a bug, they can usually report it right away and provide quick feedback to the development team. This fast turnaround helps fix issues faster in the early stages.

The Downsides of Manual Testing

Time-Consuming & Repetitive: Imagine checking the same ten steps every time you make a tiny change to your feature. Manually doing that over and over becomes incredibly tedious and slow. It’s just not efficient for repetitive tasks.
Prone to Human Error: Let’s be honest, we all make mistakes. When tests are run manually, there’s always a chance a tester might miss a step, misinterpret a result, or simply get tired and overlook something. Consistency can be a real challenge.
Limited Scalability: If you need to test your new feature across twenty different web browsers, ten different operating systems, and five different screen sizes, doing it all manually would take forever. Manual testing just doesn’t scale well for broad coverage.
Less Detailed Reporting: While a good manual tester will document thoroughly, the level of detail and consistency in reporting can vary. Automated tests, on the other hand, can generate precise, machine-readable logs every single time.

Here are more resources to understand manual testing better:

Understanding Automated Testing for New Features

Now, let’s pivot to the other side of the coin: automated testing. Think of automated testing as building a tiny, super-efficient robot that can perform your tests for you. Instead of a human clicking through a feature, we write scripts and use special tools that tell a computer exactly what to do, what to expect, and then report back on the results. It’s about letting machines handle the repetitive work with precision.

When Automated Testing Excels

Speed & Efficiency: Imagine needing to run a set of 100 tests. A human might take hours, or even days, to do it thoroughly. An automated script can rip through those same 100 tests in minutes, or even seconds. This incredible speed is a massive advantage, especially as your feature grows.
Accuracy & Consistency: Computers don’t get tired, they don’t get distracted, and they don’t make typos. Once an automated test is correctly written, it will perform the exact same steps, in the exact same way, every single time. This eliminates human error and ensures your tests are always reliable.
Regression Testing Powerhouse: This is perhaps where automation truly becomes indispensable. “Regression testing” means checking that new changes haven’t accidentally broken anything that used to work. As your new feature evolves, you’ll be constantly adding to it. Automated tests are perfect for quickly re-running all the old tests to ensure nothing has “regressed.”
Scalability: Need to test your new feature on Firefox, Chrome, Safari, and Edge, across Windows, macOS, and Linux, and maybe even on a mobile device? Doing that manually is a nightmare. Automated tests can be set up to run across many different environments simultaneously, giving you broad coverage much faster.
Detailed Reporting & Metrics: Automated tests generate clear, objective reports. You can quickly see how many tests passed, how many failed, and often get detailed logs about why something failed. This data helps teams identify problem areas and track quality over time.
CI/CD Integration: For teams using CI/CD, where code changes are constantly being merged and deployed, automated tests are absolutely crucial. They can be automatically triggered every time new code is added, providing instant feedback on its quality.

The Downsides of Automated Testing

High Upfront Investment: Building automated tests isn’t free. It requires skilled engineers to write the scripts, set up the testing framework, and sometimes choose and implement the right tools. There’s a significant initial time and resource commitment.
Maintenance Overhead: This is a big one. As your new feature changes – maybe a button moves, or a workflow is tweaked – your automated tests will likely need to be updated to match. This “maintenance” can be a continuous effort and, if neglected, leads to unreliable tests.
Limited for Exploratory/Usability Testing: Remember how manual testing was great for the “feel” of a feature? Automated tests can’t replicate that. They follow a script, so they’re not going to spontaneously discover a usability flaw or tell you if the new design is confusing for a human user.
“Brittle” Tests: Sometimes, automated tests can be too sensitive. A tiny, harmless change to the user interface (like moving a label slightly) might cause a test to fail, even though the underlying functionality is perfectly fine. These are often called “brittle” tests because they break easily.
Does Not Replace Human Judgment: While automation can verify functionality, it can’t truly replicate a user’s full experience, creativity, or ability to notice subtle design flaws or unexpected edge cases that weren’t explicitly coded into a test.

Here are more resources to understand automated testing better:

How to Test a New Feature: Automation or Manually?

Before you dive headfirst into either camp, ask yourself these questions about your new feature:

Feature Complexity & Stability

Is it brand new, with a rapidly evolving design, or a really complex user interface? If so, manual testing is usually your best bet initially. Think of it like sculpting – you need human hands to shape and refine the clay first.
Is it a stable, critical piece of functionality that isn’t expected to change much, or perhaps a behind-the-scenes calculation? These are prime candidates for automation. Once it’s solid, you want to ensure it stays solid with fast, reliable checks.

Frequency of Use & Criticality

Is this a core part of your product that users will interact with constantly, like logging in or making a purchase? If it’s a high-traffic, mission-critical path, you absolutely want strong automation to ensure it never breaks.
Is it a very niche interaction that few users will ever touch, or a one-off administrative function? For these, manual testing might be sufficient, as the return on investment for automation might not be there.

Development Stage

Are you still in the early stages of wireframing, prototyping, or quickly iterating on the design? Manual testing allows for rapid feedback and flexibility as the feature takes shape. You don’t want to build automation for something that might change completely next week.
Is the feature mature, almost ready for prime time, and you need to ensure every last detail is perfect before release? This is where automation shines for thorough, repetitive validation and finding those stubborn edge cases.

Team Resources & Expertise

Do you have limited time, budget, or team members with strong automation skills? It might make more sense to start with manual testing and gradually build up your automation capabilities over time, focusing on the most critical areas first.
Do you have an experienced team that’s comfortable with automation tools and frameworks? Leverage their strengths! They can build robust automated tests quickly.

Testing Objectives

Is your primary goal to gather feedback on user experience, design flow, and overall usability? Manual testing with real humans is essential here.
Are you focused on ensuring performance under load, security vulnerabilities, or catching any “regression” bugs that might have snuck in? Automation is your heavy lifter for these technical objectives.

Time to Market

Do you have an extremely urgent deadline for a minimal viable product (MVP)? Sometimes, a quick manual test might be the fastest way to initially get something out the door. However, be aware that this can create “testing debt” that you’ll need to address later with automation for future releases.

Risk Tolerance

How critical is this feature? What’s the impact if it fails? (e.g., A financial transaction feature has much higher risk than a new color theme). High-risk features demand robust automated checks for their critical paths. Lower-risk features might tolerate more manual oversight.

The Hybrid Approach

Here’s the big secret: very rarely will you use only manual or only automated testing for a new feature. The most effective strategy almost always involves a smart blend, leveraging the strengths of each.

Think of it like this:

Manual testing is your first line of defense. Use it for the initial exploration, to get a feel for the feature, to check usability, and for those “ad-hoc” tests where you’re just creatively trying to break things. This is where human intuition and critical thinking are irreplaceable.
Automation then becomes your reliable safety net. Once you’ve manually explored the core flows and they’ve stabilized, automate those critical paths. This ensures that every time you make a change to the feature, you can quickly and consistently verify that the most important parts still work perfectly. It’s fantastic for regression testing, making sure you don’t break old functionality while building new.

For example, you might manually test the very first version of a new shopping cart feature to ensure the user flow feels natural. Once that’s solid, you’d then automate the steps for adding items to the cart, checking out, and processing payment. This way, every time you add a new payment option or adjust shipping, those core functions are instantly verified by automation, freeing up your manual testers to explore the new changes or focus on higher-level usability.

Here’s more about the hybrid approach – Hybrid Testing: Combining Manual and Automated Testing

Still Unsure? Try This…

Well, before you do anything, understand the feature and expectations, and take time to plan. Now, try to make the most of what you have. Your goal is to provide quick feedback. So if you have any existing tests (unit, integration, or end-to-end) that can help assess what you want to check, use them by all means. You can always set up a more robust and comprehensive test suite in time, but for first line of defence purposes, use what you have to give a quick health check to your team. If you can involve more people, then split the task among them – someone can do a manual check, while someone else can look at existing tests, if any.

Use AI-based test automation tools too. Some intelligent ones, like testRigor, can generate test cases for you based on the feature description you give them as prompts. These will also help you build a test suite if there isn’t one already. You can then build upon this, but at least you have a starting point. Another advantage of using such a tool is that you can easily and quickly write test cases in plain English, which makes it easy for anyone to get involved in testing.

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