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Firefox Quantum: Developer Edition

Get the latest features, fast performance, and the development tools you need to build for the open web.

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Developer resources

MDN

The best resource for the Open Web.

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Firefox DevTools

Edit and debug HTML, CSS, and JavaScript.

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WebAssembly

Use the .wasm format as a compiler target.

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Cross-browser testing

Easily test your site on every browser and operating system.

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Events to check out

Fresh from our blog

Fresh from our blog

  • CSS Grid Level 2 – subgrid is coming to Firefox

    The subgrid feature which is part of Level 2 of the CSS Grid Specification is not yet shipping in any browser, but is now available for testing in Firefox Nightly. This is a feature that, if you have used CSS Grid for a layout of any complexity, you are likely to be pretty excited about

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  • Indicating focus to improve accessibility

    Focus indicators make the difference between day and night for people who rely on them. Focus is something that happens between the interactive elements on a page. In this post I will explain what we mean by focus, show you how focus outlines make your site easier to use for anyone who relies on the keyboard, and share examples of why it’s a best practice to never remove them.

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  • JavaScript and evidence-based language design

    In what ways can empirical evidence be used in the design of a language like JavaScript? At TC39, as stewards of the JavaScript specification, how do we answer questions about the design of JavaScript and help make it accessible to the thousands of new coders who join the industry each year? To answer this we need to experiment, and I need your help.

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Projects we love

A new layout system for the Web.

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Mozilla’s next-generation web engine.

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A systems programming language that is fast and safe.

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Powerful Web technologies that help push games to the new level.

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Build exciting virtual reality Web pages using HTML.

Start building