Skip To Main Content | Accessibility

Begin Main Content

Mozilla Developer Newsletter
🎞️ How Picture-In-Picture was built in Firefox Desktop 

Picture-in-Picture is a feature that enables users to keep videos visible when they switch tabs or applications. As with much of the Firefox browser UI, its player window is written in HTML and powered by JavaScript and CSS. 
Find Out More 👀

Other News 

Front-End Performance Checklist 2020 

Mozilla's friends at Smashing Magazine have some helpful front-end tips you can use to boost your site's performance this year in a post by Vitaly Friedman. 

✅ Start Learning Now →

A Month On Firefox 

Syntax podcast hosts Scott Tolinski and Wes Bos tried out Firefox Dev Tools for a month. In this "Hasty Treat" they report about their experience. 

🎧 Listen Now →

🐥 Tweet of the Week 🐦 

It is always frustrating when you have to interrupt your work to find the right tool. Here's a thread (and a website) developed by Stefan Judis to address that problem . . . .
Stefan Judis says: May I introduce: – I never find the proper tools when I need them I started collecting useful single-purpose online tools that are useful for web devs & I'll keep adding tools. I share my favorite ones below in a thread.
Read the Thread →

Firefox Developer Tools Tip 💡

Async stack frames

If you wish to be able to view stack frames for async functions separately from those for synchronous functions, you can set the javascript.options.asyncstack preference to true in the Firefox Configuration Editor. After you have done this, when you run code containing an async function, its traces are shown with an Async: prefix. 

Learn More →


1. ðŸ§ª Introduction to automated testing 

2. ⏳ Synchronous and asynchronous reflows 

3. 🔎 CSS Grid Inspector: Examine grid layouts

🗳️ Special Bulletin: Last chance to speak out!
Shape the world’s understanding of your work by participating in the new DevEconomics survey. Answer a few questions about tools, platforms, and technologies for a chance to win cool prizes! This survey ends January 17th, so this is your last chance. 


Global Diversity CFP Day 🌏 - Saturday, Jan 18, 2020 (locations worldwide) 

Are you a member of an underrepresented or marginalised group? Have you always wanted to become a tech conference speaker?  
Numerous workshops hosted around the globe will encourage and advise newbie speakers to put together your very first talk proposal and share your own individual perspective on any subject of interest to people in tech. Find one near you! 

Sign Up Now →
✊ You Got This 2020, Birmingham, UK. Saturday, Jan 18, 2020 

A conference for early-career web developers focused on non-technical skills needed for a happy and healthy work life. 

Sign Up Now →
FOSDEM, Brussels, Belgium. Feb 1 - 2, 2020 🆓 

FOSDEM is a free event for software developers to meet, share ideas and collaborate. You can find the Mozilla track and devroom. There will be a stellar lineup of Mozillian speakers on Sunday, February 2. 

No Registration Needed →
JSConf Hawai'i, Honolulu, Hawai'i. Feb 5-7, 2020 

This 3-day conference features two days of talks from 22 speakers, an after-party at the Honolulu Aquarium, and a gap day for social and cultural activities. Starting the night before the conference, you'll have a chance to check in early, meet other attendees, and (optionally) play dinner roulette to be assigned a dinner reservation with 4-8 random attendees. 

Sign Up Now →
PyCascades 2020, Portland, Oregon, USA. Feb 8-9, 2020 

An event organized by members of the Python communities in Vancouver, Seattle, and Portland which brings together Python users and developers from both the Pacific Northwest and around the world. 

Sign Up Now →
WebAssembly Summit, Mountain View, California, USA. Feb 10, 2020 

A one-day, single-track conference about all things WebAssembly. Sold out, but there will be...

02:10 PM, 16 Jan 2020 by Iuri Sampaio Permalink

Add comment