How can we help?

Web Browser Rendering Engines

What are Rendering Engines?

A browser rendering engine is the component of a web browser that takes HTML and CSS code as input and renders it into a visual representation of a web page. It is responsible for determining how the page’s content is displayed, including the layout, text and image formatting, and the handling of multimedia content. The engine converts the HTML, CSS, and JavaScript code into a format that can be displayed on the user’s screen. Different browsers use different rendering engines, which can affect the way web pages are displayed and the performance of the browser.

Why do browsers use Rendering Engines?

Browsers use rendering engines because they need a way to convert the HTML, CSS, and JavaScript code of a web page into a visually appealing and interactive experience. The rendering engine is responsible for formatting the content of the page and applying styles, creating the layout of elements on the page, handling the display of images and multimedia, and executing JavaScript code to make the page dynamic and interactive.

By using a rendering engine, the browser can ensure that web pages are displayed consistently across different platforms and devices, and that the code is properly parsed and rendered. This makes it easier for web developers to create and maintain websites, as they can rely on the browser’s rendering engine to handle the details of display and presentation. Additionally, the use of a rendering engine allows for the creation of complex and dynamic web experiences that would otherwise be difficult or impossible to achieve with simple HTML and CSS alone.

What Rendering Engines are there?

  1. WebKit (Google Chrome, Safari)
  2. Gecko (Firefox)
  3. Blink (Google Chrome, Opera)
  4. Trident (Microsoft Internet Explorer, Microsoft Edge (legacy))
  5. EdgeHTML (Microsoft Edge (Chromium-based))

Rendering Engine Relationships


KHTML is a layout engine for rendering HTML and XML documents. It was originally developed for the Konqueror web browser as part of the KDE project. KHTML is known for its high standards compliance, fast performance, and ability to render complex web pages accurately.

KHTML was one of the first open-source layout engines and has been widely adopted and used as the basis for other rendering engines, including Apple’s WebKit. The development of KHTML continues as part of the KDE project, and it is still used as the layout engine for Konqueror and several other web browsers.


WebKit is based on the KHTML layout engine originally developed for the KDE project’s Konqueror web browser. WebKit was initially developed as an open-source project by Apple in order to create a rendering engine for its Safari web browser. Apple has since continued to develop and maintain WebKit, and it is now used as the rendering engine for many other web browsers and platforms, including Google Chrome and the Tizen operating system. WebKit is built on top of the KHTML engine and has been extensively modified and extended to support a wide range of modern web technologies and standards.


Blink is based on the WebKit rendering engine. Blink was created in 2013 as a fork of WebKit by Google, in order to address performance and design issues with the WebKit engine. The goal of Blink was to create a more lightweight and flexible engine that could better support modern web standards and Google’s specific needs for its Chrome browser. Since its creation, Blink has evolved significantly and now has many differences from its original WebKit codebase. However, it remains highly compatible with WebKit and continues to support a wide range of web technologies and standards.


The Chromium browser is based on the Blink rendering engine. Chromium is an open-source web browser project created by Google as the foundation for its Chrome browser. Like Chrome, Chromium uses the Blink rendering engine to render web pages and provide an interactive user experience. Chromium provides the source code for the Chrome browser, allowing other organizations and individuals to create their own customized versions of the browser. Chromium is widely used as the basis for many other web browsers and platforms, including Microsoft Edge (Chromium-based) and the Opera browser.


EdgeHTML was developed by Microsoft as an independent rendering engine and was not based on any existing rendering engine. It was designed to provide fast and efficient rendering of web pages and support for modern web standards. EdgeHTML was used as the layout engine for Microsoft Edge (previously known as Internet Explorer) from its initial release in 2015 until 2021, when Microsoft switched to using a Chromium-based engine for Edge.

Chromium-Based EdgeHTML

Chromium-based EdgeHTML is the open-source web browser engine developed by Microsoft that powers the new Microsoft Edge browser. It is built on the Chromium project and replaces the original EdgeHTML engine that was used in the previous version of Microsoft Edge. The move to a Chromium-based engine was made in order to provide improved compatibility with other web browsers and to ensure that Microsoft Edge could take advantage of the latest web technologies and standards.


Gecko is an independent rendering engine developed by the Mozilla Foundation for its Firefox web browser. Gecko was first released in 1998 as the layout engine for Netscape 6, and has since been extensively developed and improved by the Mozilla community. Gecko is known for its support for modern web standards, its ability to handle complex and dynamic web pages, and its focus on privacy and security.