Mastodawn

We've completed our work on Web Security documentation on @mdn !

The entire MDN content tree has been reworked and now features in-depth information on:
- Attacks
- Defenses
- Authentication
- Threat Modeling

↪️ Blog post https://openwebdocs.org/content/posts/security-docs-sovereign-tech-agency/

Web Security docs on MDN

Open Web Docs supports web platform documentation for the benefit of web developers & designers worldwide. We are a community of web developers, standards makers, and technology companies that rely on this documentation as critical digital infrastructure, and we work cooperatively to ensure its long-term success and maintenance.

Open Web Docs

MDN Web Docs 6d ago

Firefox for Web Developers 6d ago

CSS field-sizing is newly baseline, meaning you can make various form fields size to their contents, without needing JavaScript.

MDN Web Docs 6d ago

Firefox for Web Developers Jun 16

Firefox 152 landed today, and includes web platform features like:

🎉 CSS field-sizing
🎉 Notification actions
🎉 unadjustedMovement pointer locks
🎉 getAnimations() pseudoElement option

…and more!

https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/152

Firefox 152 release notes for developers (Stable) - Mozilla | MDN

This article provides information about the changes in Firefox 152 that affect developers. Firefox 152 was released on June 16, 2026.

MDN Web Docs

MDN Web Docs Jun 15

🆕 Introducing the MDN MCP server!

Bring MDN's docs and browser compatibility data straight into your AI agent or IDE for accurate, up-to-date answers about the web platform.

• Works with VS Code, Zed, Cursor, Claude Code, Codex CLI, Claude Desktop, and more
• No more outdated guesses from training data
• Reliable Baseline and browser support info

Currently experimental. We'd love your feedback.

Learn more 👇
https://developer.mozilla.org/en-US/blog/introducing-mdn-mcp-server/

MDN Web Docs Jun 2

Firefox for Web Developers May 28

The Web Serial API landed in Firefox 151, allowing you to connect directly to microcontrollers, dev boards, 3D printers, power meters, and other serial-connected hardware from the web. Here's how it works:

MDN Web Docs May 18

Ever wish HTTP status codes were easier to remember? 🖼️

Check out this MDN cheatsheet that pairs each status code with an emoji to help you visualize what each one means, from 200 OK ✅ to 418 I’m a teapot 🫖

Check it out 👇

MDN Web Docs May 18

🦊 Firefox 150: web extensions can now use the Web Authentication API.

Extensions can create and retrieve WebAuthn credentials for any domain covered by their host permissions.

Read Now 👇
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/150

MDN Web Docs May 18

🦊 Firefox 150: <img sizes="auto"> is now supported.

Lazy-loaded images use their calculated layout size to select from srcset — no more duplicating media queries in HTML.

Read Now 👇
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/150

MDN Web Docs May 15

🦊 New in Firefox 150: the revert-rule CSS keyword.

Make a property behave as if the current rule didn't exist, letting a value from another matching rule take effect instead.

Read Now 👇
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/150

MDN Web Docs May 14

🦊 Firefox 150: light-dark() now accepts image values — not just colors.

Use it with images and gradients to adapt visuals based on color scheme.

background: light-dark(url(light.png), url(dark.png));

Read Now 👇
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/150

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