It’s not every day that a new JavaScript engine is born. Hermes is small and runs React Native on Android—and it’s open source! Welcome, Hermes Engine!

Hermes Engine does ahead of time compilation (build-time) which leads to major performance improvements. They don’t include a JIT, which doesn’t really help on mobile apps anyway. So they can keep shipped size down. This is AWESOME. #ChainReact2019

Hey, React Native just got a performance boost by using Hermes Engine (open-sourced by Facebook just now) Left - uses Hermes Engine

This is what it looks like when you are running Hermes Engine with React Native on Android:

Want to try Hermes Engine with your Android app, follow this guide to enable me!

Now that I'm released, if we were to do some videos with engineers, what types of questions you like answered.

ICYMI (or just a reminder).... @fbOpenSource released Hermes, a JavaScript engine for Android, optimized for React Native. Here is the key info: Docs: hermesengine.dev Twitter: Hermes Engine GitHub: github.com/facebook/hermes Talk: youtube.com/watch?v=zEjqDW…

Marc gives a great intro talk to what I am and some of the great performance boosts about me. Highly suggest watching

We just landed nullish coalescing and optional chaining in Hermes: github.com/facebook/herme…! Just in time for the TC39 meeting :-) #hermesengine #javascript #ReactNative

📢 #ReactNative for Windows Milestone 3 is out now! 📢 Milestone 3 includes support for RN version 0.60, native extensions developer story, integration with the high performance Hermes JS engine, E2E test infra and more! microsoft.github.io/react-native-w…

The Hermes JS Engine team has been working hard to improve memory usage. Since July we have decreased our RAM footprint by more than 30% and there are yet more significant savings to come! #hermesengine #javascript #ReactNative

We just landed another 5% memory win in Hermes github.com/facebook/herme… . It is a design change that was planned a little more than a year ago. More are coming.

Cross-compilation of Hermes to Wasm/Asm.js has finally landed on Github (for many months it was just a local experiment on my laptop)! Now anyone can compile and run Hermes in Node.js or in a browser... A NPM with a packaged Wasm/Asm.js build will follow soon.

We have recently added ES6 Proxy support to Hermes. Help us test it in your React Native 0.62 based app with npm install [email protected] and let us know!

For the next Hermes release, we have decreased the installed npm size from 120MB to 18MB! github.com/facebook/herme…

A major milestone: Hermes can now parse the entirety of Facebook's JavaScript codebase, both for web and RN, including all ES6+ features, JSX and Flow type annotations, no Babel or any preprocessing. A single server VM with 24 workers parses 450MB/s. (1 of 3)

As of yesterday, Hermes supports logical assignment operators: ||=, &&= and ??=. It ended up a fairly small change - the tests are larger than the actual code. github.com/facebook/herme… #javascript

We have a PR to enable Intl in Hermes. It is some binary increase, but not a lot, about 3% (precise numbers in the PR). github.com/facebook/herme… Should we just enable it, or should we maintain two separate builds with all the associate complexity.

With community adoption and feedback, Hermes Engine has flourished. Today, we’d like to share all the progress we’ve made and the case for making Hermes the default engine for React Native. reactnative.dev/blog/2021/10/2…

With the 0.70 release branch cut, we are excited to announce that Hermes Engine is now the default engine on Android and iOS for 0.70+ Here’s an overview of why we made the switch and all the exciting new changes the community can expect: reactnative.dev/blog/2022/07/0…