pipa (枇杷) - A fast, minimal ES2023 JavaScript runtime built in Rust.

Features

• ES2023 compliant — implements the ECMAScript 2023 specification
• Async/await built-in — first-class async/await support without transpilation
• Bytecode support — compile JavaScript to .jsc bytecode files for fast loading and execution, with configurable optimization levels (-O0 through -O3)
• Fast — outperforms QuickJS in benchmarks
• Small — ~5.2 MB binary (with repl feature)
• Zero-dependency built-in implementations for:
  • Regex/JSON/Base64/BigInt
  • Unicode
  • fetch (HTTP client), rusttls required
  • WebSocket
  • Server-Sent Events (SSE)

No external C libraries or system dependencies for the above — everything is implemented from scratch in Rust.

Benchmarks (2026-05-20)

V8 benchmark suite comparison (higher is better):

Benchmark	qjs	node	boa	pipa
Richards	980	46634	139	977
DeltaBlue	937	91283	143	1041
Crypto	1087	60024	123	1117
RayTrace	1479	80881	315	994
EarleyBoyer	2157	97221	373	1426
RegExp	338	13274	62.6	1014
Splay	2461	52843	554	2002
NavierStokes	1837	56392	292	1901
SCORE (total)	1219	54642	203	1256

Ranking: #1 node (54642) · #2 pipa (1256) · #3 qjs (1219) · #4 boa (203)

Usage

cargo install pipa-js
# Run a script
pipa script.js

# Run precompiled bytecode
pipa script.jsc

# Compile JavaScript to bytecode
pipa -compile input.js output.jsc

# Disassemble bytecode (debugging)
pipa -diss script.jsc

# Specify optimization level (default: -O2)
pipa -O3 script.js

# Start REPL (requires the repl feature)
pipa

Build

# Default build (includes REPL, fetch, and process support)
cargo build --release

# Minimal build (no REPL, no fetch, no process)
cargo build --release --no-default-features

If using pipa as a library dependency and you don't need REPL/fetch/process features, add it with default-features = false:

[dependencies]
pipa-js = { version = "0.1.1", default-features = false }

License

MIT