MDN Web Docs
@developer.mozilla.org
The official MDN Web Docs account, now on Bluesky. We deliver the best web docs around.
Visit → https://mdn.dev
Contribute → https://mdn.dev/community
Visit → https://mdn.dev
Contribute → https://mdn.dev/community
MDN is more than just a resource. It's a community of developers, contributors, and learners passionate about web development.
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to MDN
The MDN Web Docs site provides information about Open Web technologies including HTML, CSS, and APIs for both Web sites and progressive web apps.
developer.mozilla.org
February 6, 2026 at 4:00 PM
MDN is more than just a resource. It's a community of developers, contributors, and learners passionate about web development.
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
➕ Meet abs() in CSS
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
February 3, 2026 at 5:56 PM
➕ Meet abs() in CSS
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
🦊 Firefox 147 is here! What's new?
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
Firefox 147 release notes for developers (Stable) - Mozilla | MDN
This article provides information about the changes in Firefox 147 that affect developers.
Firefox 147 was released on January 13, 2026.
developer.mozilla.org
February 2, 2026 at 5:47 PM
🦊 Firefox 147 is here! What's new?
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
🆕 The URL Pattern API is Newly Available!
Use it to match and extract parts of URLs, no need to reinvent routing logic. Supports literals, wildcards, named groups, and even regex constraints.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
Use it to match and extract parts of URLs, no need to reinvent routing logic. Supports literals, wildcards, named groups, and even regex constraints.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
January 26, 2026 at 11:00 AM
🆕 The URL Pattern API is Newly Available!
Use it to match and extract parts of URLs, no need to reinvent routing logic. Supports literals, wildcards, named groups, and even regex constraints.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
Use it to match and extract parts of URLs, no need to reinvent routing logic. Supports literals, wildcards, named groups, and even regex constraints.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
🦊 Firefox 147 is here! What's new?
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
Firefox 147 release notes for developers (Stable) - Mozilla | MDN
This article provides information about the changes in Firefox 147 that affect developers.
Firefox 147 was released on January 13, 2026.
developer.mozilla.org
January 23, 2026 at 4:00 PM
🦊 Firefox 147 is here! What's new?
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
✨ CSS Anchor Positioning enabled by default
🚀 WebGPU on all macOS with Apple Silicon
🧭 Navigation API for better SPA control
🎨 DevTools improvements for pseudo-elements & animations
and more...
Release notes 👇
developer.mozilla.org/en-US/docs/...
sign() is Newly Available on Baseline ➖➕
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
January 23, 2026 at 12:53 PM
sign() is Newly Available on Baseline ➖➕
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
abs() in CSS? Yes, it's true! 🤯
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
January 19, 2026 at 9:00 PM
abs() in CSS? Yes, it's true! 🤯
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
Float16Array is Newly Available! 🆕
It represents an array of 16-bit floating point numbers in the platform byte order. If control over byte order is needed, use DataView instead. It is initialized to 0 unless initialization data is provided.
Docs 👇
developer.mozilla.org/en-US/docs/...
It represents an array of 16-bit floating point numbers in the platform byte order. If control over byte order is needed, use DataView instead. It is initialized to 0 unless initialization data is provided.
Docs 👇
developer.mozilla.org/en-US/docs/...
January 19, 2026 at 4:07 PM
Float16Array is Newly Available! 🆕
It represents an array of 16-bit floating point numbers in the platform byte order. If control over byte order is needed, use DataView instead. It is initialized to 0 unless initialization data is provided.
Docs 👇
developer.mozilla.org/en-US/docs/...
It represents an array of 16-bit floating point numbers in the platform byte order. If control over byte order is needed, use DataView instead. It is initialized to 0 unless initialization data is provided.
Docs 👇
developer.mozilla.org/en-US/docs/...
No more padding hacks 🖼️
The aspect-ratio property lets you define a fixed width-to-height ratio for any element, making responsive design easier than ever.
🎥 Great for responsive media
🎴 Cleaner layouts w/o JS
📦 Works with grid, flexbox
Read more ↓
developer.mozilla.org/en-US/docs/...
The aspect-ratio property lets you define a fixed width-to-height ratio for any element, making responsive design easier than ever.
🎥 Great for responsive media
🎴 Cleaner layouts w/o JS
📦 Works with grid, flexbox
Read more ↓
developer.mozilla.org/en-US/docs/...
aspect-ratio - CSS | MDN
The aspect-ratio CSS property allows you to define the desired width-to-height ratio of an element's box. This means that even if the parent container or viewport size changes, the browser will adjust the element's dimensions to maintain the specified width-to-height ratio. The specified aspect ratio is used in the calculation of auto sizes and some other layout functions.
developer.mozilla.org
January 16, 2026 at 4:00 PM
No more padding hacks 🖼️
The aspect-ratio property lets you define a fixed width-to-height ratio for any element, making responsive design easier than ever.
🎥 Great for responsive media
🎴 Cleaner layouts w/o JS
📦 Works with grid, flexbox
Read more ↓
developer.mozilla.org/en-US/docs/...
The aspect-ratio property lets you define a fixed width-to-height ratio for any element, making responsive design easier than ever.
🎥 Great for responsive media
🎴 Cleaner layouts w/o JS
📦 Works with grid, flexbox
Read more ↓
developer.mozilla.org/en-US/docs/...
Reposted by MDN Web Docs
The 2025 Web Almanac by HTTP Archive has been officially released! 🚀
We would like to thank all of our contributors from around the globe who made this extensive report possible!
Check out the full report here: almanac.httparchive.org
We would like to thank all of our contributors from around the globe who made this extensive report possible!
Check out the full report here: almanac.httparchive.org
January 16, 2026 at 3:00 AM
The 2025 Web Almanac by HTTP Archive has been officially released! 🚀
We would like to thank all of our contributors from around the globe who made this extensive report possible!
Check out the full report here: almanac.httparchive.org
We would like to thank all of our contributors from around the globe who made this extensive report possible!
Check out the full report here: almanac.httparchive.org
sign() is Newly Available on Baseline ➖➕
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
January 16, 2026 at 4:00 AM
sign() is Newly Available on Baseline ➖➕
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
Unlike abs(), which returns a magnitude, sign() returns the direction of a value: -1, 1, 0, or -0.
Useful when layout logic depends on whether a value is positive or negative.
Learn more here 👇
developer.mozilla.org/en-US/docs/...
Fine-tune multilingual typography with text-autospace ✨
It lets you control spacing between CJK and Latin characters.
> text-autospace: ideograph-alpha ideograph-numeric punctuation;
Now available on Baseline 2025. 🎉
Learn more 👇
developer.mozilla.org/en-US/docs/...
It lets you control spacing between CJK and Latin characters.
> text-autospace: ideograph-alpha ideograph-numeric punctuation;
Now available on Baseline 2025. 🎉
Learn more 👇
developer.mozilla.org/en-US/docs/...
January 15, 2026 at 12:00 PM
Fine-tune multilingual typography with text-autospace ✨
It lets you control spacing between CJK and Latin characters.
> text-autospace: ideograph-alpha ideograph-numeric punctuation;
Now available on Baseline 2025. 🎉
Learn more 👇
developer.mozilla.org/en-US/docs/...
It lets you control spacing between CJK and Latin characters.
> text-autospace: ideograph-alpha ideograph-numeric punctuation;
Now available on Baseline 2025. 🎉
Learn more 👇
developer.mozilla.org/en-US/docs/...
Have you met ? 🎨
The CSS data type behind color angles.
Used by hsl(), hwb(), lch(), and oklch(), represents a color’s position on the color wheel and automatically wraps around.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
The CSS data type behind color angles.
Used by hsl(), hwb(), lch(), and oklch(),
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
<hue> - CSS | MDN
The <hue> CSS data type represents the hue angle of a color.
It is used in the color functions that accept hue expressed as a single value, specifically hsl(), hwb(), lch(), and oklch() functional notations.
developer.mozilla.org
January 15, 2026 at 5:00 AM
Have you met ? 🎨
The CSS data type behind color angles.
Used by hsl(), hwb(), lch(), and oklch(), represents a color’s position on the color wheel and automatically wraps around.
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
The CSS data type behind color angles.
Used by hsl(), hwb(), lch(), and oklch(),
Learn how it works 👇
developer.mozilla.org/en-US/docs/...
Need cross-thread synchronization without freezing the main thread? 🥶
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
January 14, 2026 at 1:00 PM
Need cross-thread synchronization without freezing the main thread? 🥶
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
Firefox 146 brings WebDriver BiDi updates! 🤖
• setExtraHeaders for auto request header injection
• Node context locating for iframes
• Locale + timezone override improvements
• Better network data collection
• Reliable request IDs
Release notes 👇
developer.mozilla.org/en-US/docs/...
• setExtraHeaders for auto request header injection
• Node context locating for iframes
• Locale + timezone override improvements
• Better network data collection
• Reliable request IDs
Release notes 👇
developer.mozilla.org/en-US/docs/...
Firefox 146 release notes for developers (Stable) - Mozilla | MDN
This article provides information about the changes in Firefox 146 that affect developers.
Firefox 146 was released on December 9, 2025.
developer.mozilla.org
January 14, 2026 at 7:00 AM
Firefox 146 brings WebDriver BiDi updates! 🤖
• setExtraHeaders for auto request header injection
• Node context locating for iframes
• Locale + timezone override improvements
• Better network data collection
• Reliable request IDs
Release notes 👇
developer.mozilla.org/en-US/docs/...
• setExtraHeaders for auto request header injection
• Node context locating for iframes
• Locale + timezone override improvements
• Better network data collection
• Reliable request IDs
Release notes 👇
developer.mozilla.org/en-US/docs/...
➕ Meet abs() in CSS
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
January 13, 2026 at 9:00 PM
➕ Meet abs() in CSS
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
The abs() function returns the absolute value of a calculation, keeping numbers, lengths, or percentages always positive. Useful for safer layouts and predictable visuals.
Learn more here ↓
developer.mozilla.org/en-US/docs/...
Need to convert a color between CSS formats? 🎨
The Color format converter lets you pick a color and instantly copy it as rgb(), hsl(), hex, and more - anywhere the type is supported in CSS.
Try it here 👇
developer.mozilla.org/en-US/docs/...
The Color format converter lets you pick a color and instantly copy it as rgb(), hsl(), hex, and more - anywhere the
Try it here 👇
developer.mozilla.org/en-US/docs/...
Color format converter - CSS | MDN
This tool lets you enter or pick a color and copy its corresponding value in any CSS color format. You can use the generated color value anywhere the <color> data type is supported in CSS. This tool can also help you understand the syntax of the different color notations.
developer.mozilla.org
January 13, 2026 at 4:00 PM
Need to convert a color between CSS formats? 🎨
The Color format converter lets you pick a color and instantly copy it as rgb(), hsl(), hex, and more - anywhere the type is supported in CSS.
Try it here 👇
developer.mozilla.org/en-US/docs/...
The Color format converter lets you pick a color and instantly copy it as rgb(), hsl(), hex, and more - anywhere the
Try it here 👇
developer.mozilla.org/en-US/docs/...
Firefox 146 ships improvements for CSS devs 🎨
• contrast-color() for WCAG-friendly contrast
• display-p3-linear color space
• text-decoration-inset
• scope at-rule now on by default
• -webkit-fill-available for better compat
Release notes 👇
developer.mozilla.org/en-US/docs/...
• contrast-color() for WCAG-friendly contrast
• display-p3-linear color space
• text-decoration-inset
• scope at-rule now on by default
• -webkit-fill-available for better compat
Release notes 👇
developer.mozilla.org/en-US/docs/...
Firefox 146 release notes for developers (Stable) - Mozilla | MDN
This article provides information about the changes in Firefox 146 that affect developers.
Firefox 146 was released on December 9, 2025.
developer.mozilla.org
January 9, 2026 at 4:00 PM
Firefox 146 ships improvements for CSS devs 🎨
• contrast-color() for WCAG-friendly contrast
• display-p3-linear color space
• text-decoration-inset
• scope at-rule now on by default
• -webkit-fill-available for better compat
Release notes 👇
developer.mozilla.org/en-US/docs/...
• contrast-color() for WCAG-friendly contrast
• display-p3-linear color space
• text-decoration-inset
• scope at-rule now on by default
• -webkit-fill-available for better compat
Release notes 👇
developer.mozilla.org/en-US/docs/...
MDN is built by Mozilla and a global community of contributors — writers, translators, engineers, educators. 🌍
Together we maintain 45K+ pages helping developers build the open web.
Discover our mission & how to get involved 👇
developer.mozilla.org/en-US/about
Together we maintain 45K+ pages helping developers build the open web.
Discover our mission & how to get involved 👇
developer.mozilla.org/en-US/about
About MDN
The MDN Web Docs site provides information about Open Web technologies including HTML, CSS, and APIs for both Web sites and progressive web apps.
developer.mozilla.org
January 8, 2026 at 6:22 PM
MDN is built by Mozilla and a global community of contributors — writers, translators, engineers, educators. 🌍
Together we maintain 45K+ pages helping developers build the open web.
Discover our mission & how to get involved 👇
developer.mozilla.org/en-US/about
Together we maintain 45K+ pages helping developers build the open web.
Discover our mission & how to get involved 👇
developer.mozilla.org/en-US/about
Need cross-thread synchronization without freezing the main thread? 🥶
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
January 5, 2026 at 5:23 PM
Need cross-thread synchronization without freezing the main thread? 🥶
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
Atomics.waitAsync() returns immediately and resolves when another thread calls Atomics.notify().
Perfect for coordinating workers with SharedArrayBuffer.
Learn more 👇
developer.mozilla.org/en-US/docs/...
📷 Ever wonder what’s really happening behind your web images?
From pixels to formats to compression, you should use:
- JPEG for details
- PNG for transparency
- WebP & AVIF for web-performance
- SVG for resolution-independent graphics
Read more 👇
developer.mozilla.org/en-US/blog/...
From pixels to formats to compression, you should use:
- JPEG for details
- PNG for transparency
- WebP & AVIF for web-performance
- SVG for resolution-independent graphics
Read more 👇
developer.mozilla.org/en-US/blog/...
Pixel data from encoders to decoders | MDN Blog
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
January 2, 2026 at 9:58 PM
📷 Ever wonder what’s really happening behind your web images?
From pixels to formats to compression, you should use:
- JPEG for details
- PNG for transparency
- WebP & AVIF for web-performance
- SVG for resolution-independent graphics
Read more 👇
developer.mozilla.org/en-US/blog/...
From pixels to formats to compression, you should use:
- JPEG for details
- PNG for transparency
- WebP & AVIF for web-performance
- SVG for resolution-independent graphics
Read more 👇
developer.mozilla.org/en-US/blog/...
Happy New Year to the MDN community! 💟
Thank you for building the web with us. Writing docs, fixing bugs, reviewing PRs, and helping developers learn every day.
Here’s to better standards, better tooling, and better documentation in the year ahead. 🥂
Thank you for building the web with us. Writing docs, fixing bugs, reviewing PRs, and helping developers learn every day.
Here’s to better standards, better tooling, and better documentation in the year ahead. 🥂
January 1, 2026 at 12:00 PM
Happy New Year to the MDN community! 💟
Thank you for building the web with us. Writing docs, fixing bugs, reviewing PRs, and helping developers learn every day.
Here’s to better standards, better tooling, and better documentation in the year ahead. 🥂
Thank you for building the web with us. Writing docs, fixing bugs, reviewing PRs, and helping developers learn every day.
Here’s to better standards, better tooling, and better documentation in the year ahead. 🥂
MDN is more than just a resource. It's a community of developers, contributors, and learners passionate about web development.
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to MDN
The MDN Web Docs site provides information about Open Web technologies including HTML, CSS, and APIs for both Web sites and progressive web apps.
developer.mozilla.org
December 31, 2025 at 1:00 PM
MDN is more than just a resource. It's a community of developers, contributors, and learners passionate about web development.
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
Contribute to,
📚 MDN documentation
🤝 Help other devs
💟 Localize content
📝 Review or write on MDN
Start now 👇
developer.mozilla.org/en-US/commu...
TIL: Compression Dictionary Transport 💡
A new HTTP feature that can dramatically shrink the size of your responses, especially when serving content that changes often but includes a lot of repeated structure (think: JSON, JS, CSS).
Learn more 👇
developer.mozilla.org/en-US/docs/...
A new HTTP feature that can dramatically shrink the size of your responses, especially when serving content that changes often but includes a lot of repeated structure (think: JSON, JS, CSS).
Learn more 👇
developer.mozilla.org/en-US/docs/...
Compression Dictionary Transport - HTTP | MDN
Compression Dictionary Transport is a way of using a shared compression dictionary to dramatically reduce the transport size of HTTP responses.
developer.mozilla.org
December 30, 2025 at 4:00 PM
TIL: Compression Dictionary Transport 💡
A new HTTP feature that can dramatically shrink the size of your responses, especially when serving content that changes often but includes a lot of repeated structure (think: JSON, JS, CSS).
Learn more 👇
developer.mozilla.org/en-US/docs/...
A new HTTP feature that can dramatically shrink the size of your responses, especially when serving content that changes often but includes a lot of repeated structure (think: JSON, JS, CSS).
Learn more 👇
developer.mozilla.org/en-US/docs/...
🦊 Firefox 146 is out! What's new:
• Inspector: auto-hides unused CSS custom properties
• contrast-color() + text-decoration-inset support
• scope enabled by default
• WeakMap/WeakSet now accept Symbol keys
• WebDriver BiDi upgrades
Release notes 👇
developer.mozilla.org/en-US/docs/...
• Inspector: auto-hides unused CSS custom properties
• contrast-color() + text-decoration-inset support
• scope enabled by default
• WeakMap/WeakSet now accept Symbol keys
• WebDriver BiDi upgrades
Release notes 👇
developer.mozilla.org/en-US/docs/...
Firefox 146 release notes for developers (Stable) - Mozilla | MDN
This article provides information about the changes in Firefox 146 that affect developers.
Firefox 146 was released on December 9, 2025.
developer.mozilla.org
December 29, 2025 at 4:35 PM
🦊 Firefox 146 is out! What's new:
• Inspector: auto-hides unused CSS custom properties
• contrast-color() + text-decoration-inset support
• scope enabled by default
• WeakMap/WeakSet now accept Symbol keys
• WebDriver BiDi upgrades
Release notes 👇
developer.mozilla.org/en-US/docs/...
• Inspector: auto-hides unused CSS custom properties
• contrast-color() + text-decoration-inset support
• scope enabled by default
• WeakMap/WeakSet now accept Symbol keys
• WebDriver BiDi upgrades
Release notes 👇
developer.mozilla.org/en-US/docs/...