Featured articles
- Blog
Celebrating 20 years of MDN
MDN turns 20! Let's look at how we started, how MDN became the most trusted resource for web developers, the impact it's had on the open web, and yes, there's cake, too.
- Web APIs
CSS Custom Highlight API
The CSS Custom Highlight API provides a mechanism for styling arbitrary text ranges on a document by using JavaScript to create the ranges, and CSS to style them.
- Web APIs
Server timing
Server-Timing is a part of the Performance API and allows servers to communicate metrics about the request-response cycle to the user agent. You can collect this information and act on server-side metrics in the same way as all the other metrics processed with the Performance API.
- JavaScript
JavaScript resource management
This guide talks about how to do resource management in JavaScript. Resource management is not exactly the same as memory management, which is a more advanced topic and usually handled automatically by JavaScript. Resource management is about managing resources that are not automatically cleaned up by JavaScript. Sometimes, it's okay to have some unused objects in memory, because they don't interfere with application logic, but resource leaks often lead to things not working, or a lot of excess memory usage. Therefore, this is not an optional feature about optimization, but a core feature to write correct programs!
Latest news
- developer.mozilla.org
Launching MDN's new front end
MDN is getting a facelift 🎉. Discover what's changed, what's improved, and how navigating the site just got smoother.
- developer.mozilla.org
Pixel data from encoders to decoders
From individual pixels to fully decoded images on your screen, raw pixel data gets transformed, compressed, and efficiently delivered. Learn about the techniques and optimizations that shrink image information without any perceivable loss in quality.
- developer.mozilla.org
Color models for humans and devices
Images help bring more color and life to the web. This post describes how images are represented by humans and on different devices, with details about color spaces and vision theory.
- developer.mozilla.org
Default styles for h1 elements are changing
Browsers are starting to roll out changes in default UA styles for nested section headings. This post describes the incoming changes, how to identify if it's an issue on your websites, and hints for conformant and better-structured pages.
Recent contributions
Contributor Spotlight
Yash Raj BhartiMDN resonates with my passion to build a consistent and open web, where developers can learn and grow.Get involved
