An ant carries 50× its weight. So does this one.
Ant is a lightweight, high-performance JavaScript runtime built from scratch.
Built to carry more than it weighs without compromising performance.
$ ls -lh ant
-rwxr-xr-x⠀8.5M⠀ant*# built with -Os
-rwxr-xr-x⠀4.1M⠀ant*| Ant | Node | Bun | Deno | |
|---|---|---|---|---|
| Binary size | ~8 MB | ~120 MB | ~60 MB | ~90 MB |
| Cold start | ~5 ms | ~31 ms | ~13 ms | ~25 ms |
| Engine | Ant Silver | V8 | JSC | V8 |
| JIT | ✓ | ✓ | ✓ | ✓ |
| WinterTC conformant | ✓ | partial | ✓ | ✓ |
Ant is designed for environments where size and startup time matter: serverless functions, edge computing, embedded systems, CLI tools, and anywhere you'd want JavaScript but can't afford a 50MB+ runtime.
The engine, Ant Silver is hand-built, not a wrapper around V8, JSC, or SpiderMonkey. The JIT compiler uses a fork of MIR, a lightweight backend that enables near compiled performance.
curl -fsSL https://antjs.org/install | bashAnt targets the WinterTC Minimum Common API specification, the standard for server-side JavaScript interoperability developed by Ecma TC55.
| Suite | Pass rate | Notes |
|---|---|---|
| compat-table | 100% | 1511/1511 (ES1–ES5, ES6, ES2016+, ESNext) |
| test262 | ~64% | Improving; focus is on real-world coverage |
Measures the time to import Hono, register routes, and exit. Each runtime loads the same bench-coldstart.js script from examples/npm/hono/ that creates a Hono app with two routes, prints "ready", and calls process.exit(0). No HTTP server is actually started, this isolates module resolution and initialization overhead.
Measured with hyperfine (10 warmup runs, 100 timed runs):
hyperfine --warmup 10 --runs 100 \
'ant examples/npm/hono/bench-coldstart.js' \
'node examples/npm/hono/bench-coldstart.js' \
'bun examples/npm/hono/bench-coldstart.js' \
'deno run --allow-read --allow-env examples/npm/hono/bench-coldstart.js'| Runtime | Mean | Min | Max | Relative |
|---|---|---|---|---|
| Ant | 5.5 ms | 4.9 ms | 6.1 ms | 1.00 |
| Bun | 10.6 ms | 9.5 ms | 13.8 ms | 1.93× slower |
| Deno | 24.8 ms | 22.2 ms | 29.4 ms | 4.51× slower |
| Node | 28.7 ms | 27.1 ms | 31.2 ms | 5.22× slower |
Environment
| Detail | Value |
|---|---|
| Hardware | Apple M5 Pro, 64 GB RAM, 18 cores |
| OS | macOS 26.5.1 (arm64) |
| Ant | 12.1.15dd25d.1 |
| Node | 26.2.0 |
| Bun | 1.3.14 |
| Deno | 2.8.3 |
See BUILDING.md for instructions on how to build Ant from source and a list of supported platforms.
For information on reporting security vulnerabilities in Ant, see SECURITY.md.
We welcome contributions through pull request. See CONTRIBUTING.md for more details.
For information about the governance of Ant, see GOVERNANCE.md.