Skip to main content

Visual Regression Testing Made Easy

Save devs hours of QA through our insanely accurate visual testing tool.

14 days free trial period,
no credit card required


(Click a logo to learn more info about an integration)
Acquia logo
Pantheon logo logo
CircleCI logo
Github logo
Gitlab logo
Bitbucket logo
Browserstack logo
Tugboat logo
Wordpress logo
Behat logo
LabdaTest logo

See how we take screenshots

Custom diff algorithm

Avoid False Positives through our Comparison Algorithm

If you’ve done non functional testing before, you know that the tiniest vertical shifts due to browser rendering can lead to false positives.

Our algorithm detects these shifts and provides much better results than pixel perfect comparison algorithms.

Welcome to complete accuracy in visual regression testing.


Stickler for accuracy? So are we. Use our rich toolset to adjust your pages before taking screenshots for non functional testing.

Stackoverflow screenshot original
Stackoverflow screenshot edited
From three different staging environments, to page content alteration, to multiple integrations – Diffy has everything you need for non functional testing.
  • Custom algorithm to compare images
  • Pixel perfect compare images
  • Mask/remove elements from pages
  • Alter page content
  • Custom CSS, JS
  • Delay, scroll
  • Logged in user screenshots
  • Bypass basic authentication
  • Custom breakpoints
  • HTTP headers
  • Cookies
  • Prod, Dev, Stage environments
  • Slack notifications
  • Team management
  • Monitoring
  • Scan sitemap for URLs
  • Thumbnails preview
  • Shareable URLs to reports
  • Control number of simultaneous workers
  • Same IP address for workers for whitelisting
  • Upload your designs to compare with actual screenshots
  • Local worker
  • Any number of custom environments
  • CLI tool for integrations
  • Patternlab
  • Github
  • Gitlab
  • Bitbucket
  • Acquia
  • Pantheon
  • CircleCI
  • BrowserStack
  • LambdaTest

14 days free trial period,
no credit card required

What is Non Functional Testing?

Non functional tests are performed to verify the non functional requirements of software and applications, such as reliability, performance, security, usability, compatibility, etc.

While functional testing is about how well a system works, non functional testing is about how well a system responds. For example, functional testing tests the process for inserting data, while non functional testing tests the speed at which the data is saved.

Some types of non functional tests include performance testing, load testing, compatibility testing, usability testing, localization testing, compliance testing, and security testing.

Diffy is a free, visual regression testing platform, which falls under the category of non functional testing tools.

What is Visual Regression Testing?

Visual regression testing falls under the category of non functional testing, and it’s a type of test performed to validate that new changes applied to our code will not negatively impact our final product (be it a software, application, or platform).

Because this type of regression testing is visual, it allows us to detect which changes will affect what the final user sees when interacting with our product.

Why is picture-perfect comparison required? Oh yes.

Imagine you’ve added a More Information clickable text above a form field. But when showcased on a more narrow screen, the text overlaps with another section of your website, which makes it unclickable for certain users.

This major usability bug is only detected through visual regression testing tools, like Diffy.

Our pixel-perfect comparison algorithm ensures that the tiniest of changes won’t ruin all your hard work in the UX front.

Latest from out Blog

6 mins

Drupal And Design Systems

Design systems is a modern approach to building websites and keeping your visuals consistent. In this article we will talk about different ways you can integrate design systems in your theme.
7 min

25 Web Dev & QA Testing Statistics Every Developer Should Know [2022]

Trends move quickly in the web development and QA testing space. These trends can help predict where the QA and testing industry is headed. Development teams can adapt emerging best practices and methodologies while gaining a better understanding of the challenges they face throughout the development cycle.


7 min

Regression Testing: Your Step-by-Step Action Plan

Regression testing can be an overwhelming task. You can try to do too much and fail because of a lack of resources. In this article we will talk about how you can start with small practical steps to get results fast. Once you set up basic tests like visual regression testing you can start with more complex implementations including automation.