An unsafe-free Rust rewrite of QuickJS, targeting semantic Feature Parity with the official QuickJS 2026-06-04 release and its ES2025 behavior.
The engine is runnable, but it is not at Feature Parity yet. Implemented slices
include binary data and Atomics, collections and weak references, Promise jobs,
Unicode behavior, class elements, and static-module graphs with live bindings,
top-level await, import attributes, JSON modules, import.meta, and dynamic
import(). The Rust embedding API and file-module CLI also expose QuickJS's
canonical, host-populated import.meta object. JavaScript-valued module-host
errors retain their exact values and object/Symbol identity. Context-aware
module-host callbacks can synchronously compile and return same-Context
modules, including nested loader re-entry protected by a finite host-stack
budget. Parse-in-progress module identities and source-order request prefixes
are visible to those callbacks in QuickJS order, with unsafe failed identities
represented deterministically. Script, ECMAScript Module, and JSON-module
loader boundaries accept byte-exact source buffers, and the file CLI preserves
those bytes end to end. The remaining conformance gaps are still parity work.
The authoritative R3fb Test262 baseline records 79,597 full-corpus passes out of 102,037 variants (78.008%), with 79,647 eligible variants (78.057%). The 79,597 / 79,647 runnable pass rate (99.937%) is a secondary quality measure, not the headline compatibility metric.
Open the browser playground →
— it runs this Rust engine's actual WebAssembly build, not host eval. The
page reports its exact build commit, QuickJS target, and browser host policy.
Its curated Script-goal examples include a function returning 42 and the
Atomics.wait boundary. The playground is a pre-parity milestone, not a
Feature Parity claim.
Rust 1.88 or newer is required.
git clone https://github.com/pocket-stack/quickjs-oxide.git
cd quickjs-oxide
./scripts/demo-42.sh # 42
cargo run --quiet --bin qjs -- --print-result -e \
'(function (a) { return a + 1; })(41)' # 42
cargo run --quiet --bin qjs -- -e 'console.log({ answer: 42 })'
# File modules: -m/--module, --script, .mjs and source detection
cargo run --quiet --bin qjs -- examples/module-42.mjs # 42The file loader follows QuickJS policy: .json is strict JSON,
type: "json5" selects QuickJS extended JSON for any suffix, and a .json5
file without that attribute remains a JavaScript module. Main files and
dependencies are read as explicitly sized byte buffers.
- Current implementation status
- Pinned Test262 baseline and metric definitions
- Parity acceptance contract
- Playground build and trust boundary
- Pinned upstream release
- Test262 gate data and archived history
cargo test --locked --workspace --all-targets
./scripts/test-test262.sh --check
./scripts/test-test262.sh --focused
TEST262_WORKERS=2 ./scripts/test-test262.sh --full
./scripts/test-web-playground.sh
npm ci && npx playwright install chromium && npm run test:browser