Look at the below image. What is the first thing that kept you hooked to this image?
Let me guess! The interface obviously. The above image depicts a cross-browser testing tool- LambdaTest. This is how the website looks on the browser Google Chrome version 84 and Windows 10 Operating System with 1024 resolution. Now, look at the below image.
This is how the same website looks on the browser – Microsoft Edge version 87 and Windows 10 Operating System with 1024p resolution.
Yes, there is not much difference between the two. But can we say the same for other combinations of browsers and operating systems?
Talking about browsers and operating systems, the most favoured browsers in recent times are Google Chrome, Microsoft Edge, Mozilla Firefox, Safari, Internet Explorer, and Yandex. And let’s not forget all the versions of each browser. The latest version of Google Chrome is version 84 and since 2013, Google Chrome has released 45+ browser versions. Now, imagine the picture of distinct operating systems. We have Windows, Mac, and Linux.
You must be wondering why we are debating over operating systems and browsers! You must be like – “We know all this, state your concern!”
Well! Then, my concern is regarding the UI testing of all these combinations to inspect the interface of any website. We know that on different browsers, your website may look and behave distantly because every browser has its own rendering engine and scripting language which raises cross-browser compatibility issues.
Isn’t it too time-consuming and effort-consuming to test each and every combination one on one?
We need to find an alternative solution to this issue. And the solution is “Screenshot Testing”.
Yes! You read it right! Screenshot testing is a cost-effective way of performing UI Testing. It also consumes less amount of time than the usual manual testing if the aim is just to see how the website looks on different browsers. In this article, we are going to study Screenshot testing and how can we pick the right tool for Screenshot testing? So, let us start without any ado!
What is Screenshot Testing?
Screenshot testing is an end-to-end testing technique that uses an URL to capture the screenshot of your website across different browsers, browser versions, and operating systems. And then you can match the results with the expected ones.
It is the easiest and simplest technique to validate that the website is functioning as expected. Also, with screenshot testing, we can keep an eye on the responsiveness of all the browsers. You can also check how the web page is rendered on different browsers or whether the user interface is broken. For an instant, you can take screenshots from Microsoft Edge and then compare your picture with Chrome or Safari or Mozilla, or Opera.
We agree that Screenshot testing cannot solve all of your problems but we can surely say that it will reduce your workload and save time in the execution process. Also, it is inexpensive and really fast! So, when it’s a win-win situation then why not go for it.
How To Pick The Right Tool?
Alas! finding the right tool for screenshot testing that can match all your needs and can provide results in less time can be a task. But now that you are here you need not freak out. Here is the checklist that you should follow while looking for the right tool.
- Quantity
When you perform screenshot testing, you have to ponder over this point that “how many screenshots can the tool take in one go!”
This is considered to be the most important aspect as screenshot testing is usually practised to reduce the workload and decrease the time constraints. For example, Screenshot testing provided by LambdaTest delivers 25 screenshots from different operating systems and browsers of your website in one go.
- Results of testing
Once you are done with testing your website, the next step is generating the results of your test cases. You need to make sure that even if there is any little variance in the screenshots, it must be highlighted by the tool. Like Chromatic highlights the dis similitudes.
- Complexity
Complexity is a big issue. No one wants to use a tool that is complex to use and hard to handle. The tool should be easy to understand and use. Remember the more the complexity the more are the chances of bounce rates.
You can run a small complexity test of the tool to determine its complexity and choose the right tool very wisely.
- Security of data
Data security refers to the protection and safety of the data from unauthorized and unknown sources. Your data is your most valuable asset and keeping it safe is your foremost priority.
The tool that you’ll be using should be designed in a manner that it is cyber-attack proof, no one can breach the data, authentication proof, and data should not be leaked from anywhere.
- Plug-ins and Extensions
This is the part where you can have fun with the tool. Plug-ins and extensions are used as they provide additional benefits to the product. Before using any tool, don’t forget to check on the list of all the plug-ins and extensions.
Various Screenshot Testing Tools
Companies use image comparison tools to test their website and here is the list of the most reliable screenshot testing tools available. (Arranged in alphabetical order)
- BackstopJS
BackstopJS is an open-source visual regression testing tool for your web applications. It was developed in the year 2014 by Garris Shipon with his teammates. It is a screenshot application testing tool for your responsive website. With the help of Chrome headless, BackstopJS also supports screen rendering. And if you want to add your own interactions, you can implement them using Puppeteer and ChromeJS scripting.
It runs as a standalone package app, both globally or locally. The backstopJS is super easy to use. Just 3 commands would be enough for a long way. Can you believe this!
- Chromatic
Made and maintained by storybook core maintainers, Chromatic is one of the finest screenshot testing tool. It is also a review tool for UI components and libraries. It is an open-source platform that was first launched on September 19, 2017.
The biggest pro of using Chromatic is that it highlights even the slightest of difference. The difference can be seen in bright green. If you try Chromatic I am sure you won’t regret it.
- LambdaTest
Source Code: www.lambdatest.com
LambdaTest is a cross-browsing cloud-based testing tool. With LambdaTest you can perform Screenshot testing and also can share those screenshots with your teammates. It provides you with the facility to capture 25 screenshots in one go from different browser-operating system combinations of your choice. There are many other features of LambdaTest which makes it different from other screenshot testing tools. Click here to know more.
Apart from screenshot testing, you can also perform responsive testing, real-time testing, and functional testing. It also supports multiple programming languages such as Python, Ruby, Javascript for your automation needs. This platform also provides you with the feature of cross-browser testing on 2000+ browsers.
- PhantomCSS
Source Code: https://raw.github.com/Huddle/PhantomCSS/master/readme_assets/Phantom%20CSS.png
PhantomCSS is a visual regression testing tool that takes a screenshot of the execution of the first test and saves it as the baseline image. Phantom CSS is an open-source tool and is built on three components. The three components are :
- PhantomJS
- CasperJS
- Resemble.js
Creating a baseline image is very essential as it will be beneficial in future tests. On sensing any change in the website you can again run the test in PhantomCSS and then compare the result with the baseline image. The test is a pass when the two images match each other. And if there is any dissimilarity in the two images then the test fails. And a new screenshot, showing the difference is created.
- Puppeteer
Source Code: https://user-images.githubusercontent.com/10379601/29446482-04f7036a-841f-11e7-9872-91d1fc2ea683.png
Puppeteer was launched in April 2018. It is a Node library that provides advanced level API to control Chrome or Chromium. By default, it runs headless and on configuring it we can even run non-headless Chrome or Chromium.
You can generate screenshots and pdf of pages using Puppeteer. You can also test chrome extension and automate form submission, UI Testing, Keyboard, etc.
Why is LambdaTest Different?
LambdaTest provides many features that are different from any other tool. Let us take a look at them.
- You can test your locally hosted websiteusing the Lamba tunnel. The tunnel provides a secure shell connection between your machine and the cloud server.
- With the help of the In-Built image editor, you can highlight any UI variance in the captured screenshot.
- You can share the resultswith your teammates through Instant Messages or Emails.
- You can keep a track of all your tests and sessions and you can find them in the history or recent test sessions.
- While testing your mobile for responsiveness, you can use LT browserby LambdaTest to capture screenshots and test them.
- If you wish to schedule your automation sessions, then it is also possible using our scheduler. You just need to choose the time, day and frequency of your session and the screenshots will be mailed to you.
- LambdaTest also provides WordPress plugins and chrome extensionsto help the users perform automated screenshot testing.
You can go to the LambdaTest website to learn how to use the screenshot testing tool. Trust me! It is super easy and handy to use. We hope you enjoy this article and learnt some insights on the screenshot testing.