Project Description

Facebook has launched a new javascript called Hermes. This will help the React Native android applications to improve their performances. Hermes is developed to increase the startup time, decrease the Ram usage and resulting a smaller app size. Hermes is now present in all its React Native apps. Most importantly this javascript has also been used in Facebook’s Crisis Response & Oculus Companion app. Here are some features of Hermes:

Features of Hermes

  • Instead of making the users wait, parsing and compiling JavaScript on-device can be done at the build time.

  • Ahead of time compilation. Hermes is developed for fast startup.

  • Hermes helps the React Native apps to decrease the memory usage of the device and thus resulting a smaller app size.

  • As per the need bytecode can be mapped and loaded from the flash memory gradually.

  • In chunks an on-demand virtual address space is located to avoid the need of estimating the heap size and overhead minimizing. And the free memory can easily be returned to OS.

  • Hermes targets ES6, which is now not being used in the React Native applications.

Facebook has already started open sourced Hermes integration to the React Native apps; so that the developers can opt into the javascript immediately.