The Next Generation of Cross Browser Testing is Ultrafast

Cover Photo by Marc-Olivier Jodoin on Unsplash

This article was written by Daniel Levy.


The Ultrafast Grid represents the first true breakthrough in cross-browser testing architecture since it’s initial inception many years ago. It’s important to understand the differences between the traditional approach to cross browser testing and the modern approach that Applitools has taken.

Early Web

Fast forward to the late 90’s where usage of all-in-one providers diminished and a browser war began between IE and Netscape. At the time, web standards were poorly defined and web applications were gaining popularity. This created the need to test applications across browsers to ensure functional and visual defects were detected. Cross-browser testing was born — and quickly evolved from companies creating a local matrix to the usage of cloud-based VMs.

HTML 5 & Responsive Web

Traditional cross browser testing executes tests built on your existing testing framework, (think Selenium), across all browser, viewport, and OS combinations specified by the engineer. This means a 2 minute test would need to run separately across each combination in the matrix. The issue that began to arise was the result of brittle functional tests, and the need to maintain connectivity and connection of those tests for every single browser, viewport, and OS combination.

The Modern / Intelligent Web

Because of standards, you might expect any combination of browser, OS, device, and viewport size to function identically. And, unless you use platform-specific or device-specific functionality, that’s a reasonable expectation. So, what should you expect from cross-browser testing?

Functional differences between modern standards-compliant browsers happen rarely. You expect the browser to receive and process the same HTML, CSS, and JavaScript from the server. Rendering differences do occur, though, as each platform uses its own rendering engine. And those rendering differences can result in real-world functional differences from a user’s perspective.

So, if your cross-browser tests run the same DOM across different devices, do you need to keep asking the server to serve up the same content multiple times to find defects caused by rendering?

The Next Generation of Cross Browser Testing

Applitools Ultrafast Grid leverages Visual AI (AI powered computer vision) to test across browsers faster and with more coverage than ever possible.

Here is how it works:

Your test suite is executed locally on a single browser. During execution, the Applitools SDKs capture the DOM & CSS rules for every browser state and sends it to the Ultrafast Grid. This is a one-way connection thus does not require a reverse proxy or IPSec VPN — something any IT team with a focus on security can appreciate.

Next, the Ultrafast Grid renders the DOM in parallel using containers and grabs a screenshot across each browser and viewport combination. The screenshots are then sent to Applitools Eyes for Visual AI analysis. This entire process is blazing fast — in a matter of seconds you are viewing results from the test run.

Because the tests are executed only once, connectivity and connection to the browser are only required for that single run which results in incredible stability of the run. What’s more — that single run also reduces the required set-up and tear down of data (data consumption). Parallelization and containers result in incredible speeds and Visual AI can replace many of the brittle locators in your test code resulting in further stability.

Above: Diagram of Applitools Ultrafast Grid


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