That sigh of relief when the blank white page finally shows something? That's First Contentful Paint (FCP). Learn what First Contentful Paint measures. Debug FCP with Performance Insights in the updated Chrome DevTools Performance panel and make your website faster - and if stuck, Ask AI for help.

The CrUX 202510 release is out, and there's an important update on the CrUX Dashboard deprecation. Get all the info from Barry's thread. 👇

🎧 @una.im and @bram.us dive into the latest advancements in CSS with state-based container queries → goo.gle/4p4QzhN Learn how to create responsive and dynamic user experiences by querying the scroll state of UI elements, including 'stuck,' 'snapped,' and 'scrollable' states.

That feeling when you open a performance trace and it has more plot twists than a mystery novel. 🤯 AI assistance in Chrome DevTools analyzes those complex traces for you, right in your browser. See how it works → goo.gle/4gt9Qq0

Before: Juggling your IDE, documentation, and the DevTools Console just to write a simple script. After: Typing a comment and letting Gemini complete the code for you directly in DevTools. Welcome to a more productive workflow →goo.gle/3JFWTNF

The ::details-content CSS pseudo-element is now part of Baseline → goo.gle/3KOg08B You can now style the expandable/collapsible contents of a <details> element, enabling smoother transitions and custom background colors for a better user experience.

Some bugs are real mysteries. AI assistance in DevTools is the detective you need to solve them. 🕵️‍♀️ Swipe through these case files to see how it works → goo.gle/3JGbBUD

Speed up content workflows with the Summarizer API → goo.gle/3IfOkZk The Summarizer API can be used to generate different types of summaries in varied lengths and formats, so users in your CMS can save time on summarizing that next lengthy article.

When your AI agent gets a major power-up 🔋 See how the Chrome DevTools MCP server works → goo.gle/3KU63q2

Ever thought about writing #WebAssembly by hand? 🤔 Authors Patrick @dubroy.com and @marianoguerra.org think it's crucial for learning. They join #WasmAssembly host Thomas Steiner to discuss their ebook, "WebAssembly from the Ground Up" → goo.gle/3Ln67Pp

Episode 5 of Web Dev Acronyms is all about Time to First Byte ⏱️ Learn about this foundational metric for server response time and how to measure it as part of your LCP analysis in the DevTools Performance panel.

Chrome 143 beta is live → goo.gle/3Wr7nTX This release includes CSS anchored fallback container queries, FedCM support for structured JSON responses, a new Digital Credentials API origin trial, and more.

Chrome 142 is rolling out now → goo.gle/49oMbFy This release features :target-before/:target-after pseudo-classes, range syntax for style container queries, the new interestfor attribute, and more.

No tricks, just treats🍬 You're creating the spookiest costume imaginable: a web developer debugging a critical issue. What prop or accessory makes the costume truly terrifying (and authentic)?

Your CSS debugging got a major upgrade. AI assistance in Chrome DevTools can analyze your code to find conflicting styles and suggest the fix in real time. It's like having a CSS expert built right into your browser→ goo.gle/4m9xBou

Attending #perfnow? This is your chance to talk all things Chrome DevTools (MCP) and performance agents, right with the team.

Lab data is great, but what are your real users experiencing? That's where CrUX comes in. The latest episode of Web Dev Acronyms explores Chrome User Experience Report and how to bring its field data right into DevTools.

The final countdown is on! ⏳ You have 24 hours left to submit your project → goo.gle/ChromeAIChallenge2025 The Google Chrome Built-in AI Challenge closes on October 31st at 11:45 PM PT. Don't miss your chance to compete for up to $14,000!

👻 Don't let the blank page haunt your users this Halloween. The Writer API is here to help exorcise those writer's block demons and get that product description out the door. Publish content faster with the Writer API → goo.gle/4pPMMG5

Building secure, real-time communication apps just got a major boost. WebRTC Encoded Transforms are now a Baseline Newly Available feature, enabling high-performance, end-to-end encryption on encoded frames → goo.gle/3Iy3md6

Want your Google Chrome Built-in AI Challenge submission to stand out? Use the Proofreader API→ goo.gle/ChromeAIChallenge2025 Build an app or extension that can: 💬 Correct user chat messages ✍️ Edit blog comments instantly 📝 Fix errors in documents on the fly

Decode base64 strings into byte arrays with Uint8Array.fromBase64() → goo.gle/4nPXxH9 Now part of Baseline, it's the preferred alternative to atob() for easier handling of binary data.

🏆 And the Baseline Tooling Hackathon winners are... → goo.gle/47KQ6ve Nearly 3,000 developers submitted hundreds of innovative projects, but only 3 could take home their share of the $10,000 prize pool.

The CSS Podcast is back for a new season → goo.gle/4nrYxAe 🎉 @una.im and @bram.us kick things off by diving into two powerful new features: inline conditionals with if() and custom functions.

🔧 Let your coding agent identify and fix INP issues for you → goo.gle/3IPT2No With Chrome DevTools MCP, your coding agent can measure performance for specific user interactions to find and resolve slow UI responses - on its own with the help of the browser!

Match URLs with a powerful, standardized syntax using the URL Pattern API → goo.gle/47iTr3o Now part of Baseline, this API provides a built-in way to create URL pattern matchers that can be used against URLs or individual URL components.

Chrome now comes with the built-in AI model Gemini Nano 🧠. ⬇️ But when is the model downloaded? 🆕 How do updates work? 🗑️ Does the model ever get purged? All these questions are covered in my new article "Understand built-in model management in Chrome"! 🔗 developer.chrome.com/docs/ai/unde...

Click... wait... anything happening? 🤷 We've all been there. That delay is what Interaction to Next Paint (INP) is all about.

✍️ Generate and refine text with built-in AI in the Google Chrome Built-in AI Challenge → goo.gle/ChromeAIChallenge2025 Use the Writer API to create new content and the Rewriter API to revise and restructure it, all within your own web application.

📄 Parse HTML input with the new parseHTMLUnsafe() method → goo.gle/4mXOH9d Now part of Baseline, this static method creates a new Document instance from an HTML string and allows for optional sanitization.

Welcome to Web Dev Acronyms, a new series decoding the alphabet soup of web performance 🎬 First up is LCP. We're explaining where to find it and how to get help debugging it.

Proactively speed up future requests with dns-prefetch → goo.gle/4q1uO3I Now part of Baseline, this hint tells the browser to perform DNS lookups for other origins in the background, reducing latency for your users.

Don't let a broken form frustrate users 😠 Here's how to use Chrome DevTools MCP to let your coding agent solve the problem → goo.gle/3KIz4Vx ➡️ Let it use your local dev server ✍️ Auto test w/ dummy data 🖥️ Read the console output & network log to find the server error

The latest episode of What's New in DevTools covers Baseline integration, AI assistance, Save-Data header emulation, and more → goo.gle/4odg8NL Watch the full recap of updates from Chrome 139-141 to see these powerful new features in action and improve your debugging workflow.

🆕 The 202509 Chrome User Experience (CrUX) release is now live on BigQuery! Check out the announcement post for the full info: groups.google.com/a/chromium.o... Highlights below 👇 🧵 1/7

A powerful performance feature is now Baseline Newly Available. Stemming from Interop 2023, content-visibility allows the user agent to skip rendering work for an element until it's needed, speeding up initial page loads→ goo.gle/3KE5XCS

👋 Say goodbye to passwords and hello to a more secure future → goo.gle/48QK4tX Join our webinar on Nov 4th to explore modern web identity solutions, including passkeys and Sign in with Google, to streamline the user journey and boost security.

Unleash the power of Hybrid AI in the Google Chrome Built-in AI Challenge → goo.gle/ChromeAIChallenge2025 Build with Firebase AI Logic or the Gemini Developer API to create innovative apps that leverage on-device and cloud capabilities.

🛠️ Using Baseline in your project's toolchain just got easier → goo.gle/4odpQiK September's Baseline updates include a major Browserslist integration, 21 new widely available features, and quality-of-life improvements for the timeline tool.

Lighthouse 13 has been released and includes the final move to Insights performance audits as announced previously. developer.chrome.com/blog/lightho...

October 17th is just around the corner! This is your final call to register for the in-person #WebAI summit in the Bay Area. Don't miss out on a full day of talks and demos on client-side AI. 🎟️ Grab your spot before it's too late → goo.gle/WebAISummit2...#WebAI

Chrome for Android can now help users adopt passkeys more seamlessly. If a user signs in with a saved password , your website can request that an associated password manager (in many cases on Chrome is Google Password Manager) creates a passkey automatically. developer.chrome.com/blog/automat...

Manually sorting support tickets by language can be slow and inefficient 🥴 The Language Detector API works client-side to detect the language of input text and labels it automatically, helping to speed up your workflows. Build a smarter support queue → goo.gle/4pmDiSJ

Stop guessing and start debugging responsive styles automatically with Chrome DevTools MCP → goo.gle/3IPT2No Learn how a coding agent can find a visual bug on a specific device size, analyze the source code, update the CSS, and verify the fix with a live browser screenshot.

Come join us in the Bay Area for Google's #WebAI summit, where you'll hear from leaders at @HuggingFace, @Arm, @Google and more. If you can make it in person, sign up here → goo.gle/WebAISummit2...#WebAI If not, no need to RSVP—videos will be on @YouTube soon!

As an experiment, we (the Firefox team) wanted to try a new way to get feedback on which Interop proposals matter most. So, here's a web app where you can rank the proposals you care about, giving us data we can use when reviewing which ones to champion. interop-rank.jakearchibald.com

User speaking one language 🤝 agent speaking a different language. This is possible with the Translator API. Power your support chat so users can write in their first language while your site translates it for your agent. Enhance your chat experience → goo.gle/3Ik3Vab

Too much text, too little time? Our Summarizer API can help users with that. Distill pages into key points instantly. Imagine what you could build with that power. Show us in the Google Chrome Built-in AI Challenge → goo.gle/ChromeAIChallenge2025

Chrome 142 beta has landed → goo.gle/486QAMX This release includes :target-before and :target-after pseudo-classes, origin-keyed process isolation, an easier way to manage view transitions, and more.

If you've been thinking about entering the Baseline Tooling Hackathon, the clock is ticking! 3 days left 2800 developers $10,000 in prizes baseline.devpost.com