@dimforge/rapier2d

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2D physics engine for the JavaScript programming language (official bindings).

Feature selection

Multiple NPM packages exist for Rapier, depending on your needs:

• @dimforge/rapier2d or @dimforge/rapier3d: The main build of the Rapier physics engine for 2D or 3D physics simulation. This should have wide browser support while offering great performances. This does not guarantee cross-platform determinism of the physics simulation (but it is still locally deterministic, on the same machine).
• @dimforge/rapier2d-simd or @dimforge/rapier3d-simd: A build with internal SIMD optimizations enabled. More limited browser support (requires support for simd128).
• @dimforge/rapier2d-deterministic or @dimforge/rapier3d-deterministic: A less optimized build but with a guarantee of a cross-platform deterministic execution of the physics simulation.

Bundler support

Some bundlers will struggle with the .wasm file package into the builds above. Alternative -compat versions exist which embed the .wasm file into the .js sources encoded with base64. This results in a bigger package size, but much wider bundler support.

Just append -compat to the build you are interested in: rapier2d-compat, rapier2d-simd-compat, rapier2d-deterministic-compat, rapier3d-compat, rapier3d-simd-compat, rapier3d-deterministic-compat.

Nightly builds

Each time a new Pull Request is merged to the main branch of the rapier.js repository, an automatic canary build is triggered. Builds published to npmjs under the canary tag does not come with any stability guarantee and does not follow semver versioning. But it can be a useful solution to try out the latest features until a proper release is cut.

Changelog

0.19.0 (05 Sept. 2025)

Modified

• Update to Rapier 0.29.0 which includes performance improvements for scenes involving a lot of contact constraints. See https://github.com/dimforge/rapier/pull/876 for details.
• Renamed the RigidBody.invPrincipalInertiaSqrt and .effectiveWorldInvInertiaSqrt methods to RigidBody.invPrincipalInertia and .effectiveWorldInvInertia (removed the Sqrt suffix). These methods will now return the actual inverse angular inertia matrix rather than its square root.
• Removed methods related to the legacy PGS solver: World.numAdditionalFrictionIterations, switchToStandardPgsSolver, switchToSmallStepsPgsSolver, switchToSmallStepsPgsSolverWithoutWarmstart.