---
title: "Hermes"
description: "Optimizing React Native applications with the Hermes JavaScript engine"
url: https://www.callstack.com/insights/hermes-javascript-engine
updated: 2026-10-22T13:55:50.680Z
---

# Hermes

Optimizing React Native applications with the Hermes JavaScript engine

Hermes is React Native's optimized JavaScript engine that improves app performance, reduces memory usage, and decreases app size. Discover how to enable and configure Hermes, debug applications effectively, and leverage its capabilities to create faster, more efficient React Native applications.

## Articles, podcasts, events and case studies

- [Why You Don’t Have to Minify JavaScript Code in React Native Apps](https://www.callstack.com/blog/why-you-dont-have-to-minify-javascript-code-in-react-native-apps) (Article, 12/18/2025): React Native skips JavaScript minification in production because Hermes handles dead code elimination at the bytecode level. Here’s how and why it works.
- [From Static Hermes to Hermes V1: The Road to Default](https://www.callstack.com/podcasts/from-static-hermes-to-hermes-v1-the-road-to-default) (podcast, 12/4/2025): Nicola Corti (Meta) explains the evolution of Static Hermes into Hermes V1, the performance boosts it ships, and the (experimental) path to making it the new default engine.
- [Hermes V1: What It Is, What It Isn’t, and What’s Next](https://www.callstack.com/events/hermes-v1-what-it-is-what-it-isnt-and-whats-next) (Event, 11/6/2025): Łukasz Chludziński, Szymon Chmal, and Matt Hargett unpack Hermes V1, covering what’s new, what’s changing, and what’s ahead for React Native performance.
- [How to Optimize Your Android App Startup Time With Hermes](https://www.callstack.com/blog/optimize-android-app-startup-time-with-hermes) (Article, 12/4/2021): Learn how to achieve better performance and optimize Android app startup time with Hermes.
- [Technical Guide, Part 2: Integrating Hermes With React Native](https://www.callstack.com/blog/technical-guide-integrating-hermes-with-react-native) (Article, 6/14/2021): Interested in the Hermes engine? Check the second part of our expert guide to find out how to integrate Hermes with React Native.
- [Technical Guide, Part 1: Compiling Hermes for Apple Platforms](https://www.callstack.com/blog/technical-guide-compiling-hermes-for-apple-platforms) (Article, 5/26/2021): Want to use Hermes in your React Native app on iOS? Find out how to compile Hermes for Apple platforms. Check the first part of our expert technical guide.
- [React Native 0.64 With Hermes for iOS](https://www.callstack.com/podcasts/react-native-0-64-with-hermes-for-ios-ep-5) (podcast, 5/11/2021): Discover how Hermes boosts React Native performance on iOS and macOS, with insights into AOT, bytecode precompilation, and the future of Hermes support.
- [Hermes Performance on iOS](https://www.callstack.com/blog/hermes-performance-on-ios) (Article, 4/21/2021): Wondering how the Hermes engine performs on iOS? We tested it on a React Native mobile app. Check the results and see how it compares to JSC.
- [Bringing Hermes to iOS in React Native 0.64](https://www.callstack.com/blog/bringing-hermes-to-ios-in-react-native) (Article, 4/14/2021): Hermes is now available for iOS as well. Find out more about this JS engine - check the first part of our series on bringing Hermes to iOS.

## Want to achieve better performance with Hermes?

We guide teams in optimizing React Native with the Hermes engine.

[Talk to our team](https://www.callstack.com/contact)