JerryScript
FreeA JavaScript engine intended to run on a very constrained devices such as microcontrollers. Designed for the Internet of Things.
About JerryScript
JerryScript is an ultra-lightweight JavaScript engine designed for resource-constrained devices such as microcontrollers. It can run on devices with less than 64 KB of RAM and less than 200 KB of flash memory. The engine is fully compliant with ECMAScript 5.1 and achieves 70% compliance with ECMAScript 2025 (Kangax table). It is written in C99 for maximum portability, has a binary size of 258 KB when compiled for ARM Thumb-2, and provides snapshot support for precompiling JavaScript source code to bytecode. A mature C API makes it easy to embed into applications. JerryScript is open source under the Apache License 2.0, maintained by the JS Foundation.
Key Features
Pros & Cons
- Extremely low memory and storage footprint (can run on devices with <64KB RAM and <200KB flash)
- Full ECMAScript 5.1 compliance and partial ES2025 support
- Written in C99, easy to port to different platforms
- Open source under Apache License 2.0
- Only 70% ECMAScript 2025 compliance, not fully up-to-date with latest JavaScript features
- Designed specifically for constrained devices; may lack performance optimizations for general-purpose systems