Brotli decompressor for browsers and web workers with WASM, which still has a small size (about 300KB)

brotli, brotli-decompressor, wasm, rust
npm install brotli-dec-wasm@2.0.1




Brotli decompressor for browsers and web workers with WASM, which still has a small size (about 300KB)

If you are looking for a compressor, see Alternatives



Starting from v2.0.0, this package becomes an exact drop-in replacement of brotli-wasm. You can simply replace import brotli from 'brotli-wasm' with import brotli from 'brotli-dec-wasm' to switch from or to this package.

More detailed usage can be found in brotli-wasm Usage section.

You can also refer to the unit tests in brotli-wasm:test/brotli.spec.ts to see how to use by examples.


Broken in webpack 5

BREAKING CHANGE: Since webpack 5 WebAssembly is not enabled by default and flagged as experimental feature. You need to enable one of the WebAssembly experiments via 'experiments.asyncWebAssembly: true' (based on async modules) or 'experiments.syncWebAssembly: true' (like webpack 4, deprecated).

Set experiments.syncWebAssembly: true for old code, experiments.asyncWebAssembly: true for new code.


The code is quite simple, which is just a wrapper of the crate brotli-decompressor (other than crate brotli, though brotli depends on brotli-decompressor)

Build configuration such as opt-level = "s", are fine-tuned with manual tests, to make the bundle as small as possible


The package is at least used by myself in my blog mylmoe, which provides a page to (de)compress Brotli online


  • brotli-wasm: A reliable compressor and decompressor for Brotli, supporting node & browsers via wasm. If you need a compressor, use it. Actively maintained by an organization.

More alternatives are available in brotli-wasm Alternatives section

One surprising thing is, in js folder of the offical google/brotli repository, there is a pure JavaScript decompressor implementation, which is even a little smaller than this package in size. However, it is not published on NPM. I can not imagine the reason and since that, I do not suggest you to use it.


At least >= v1.3.3

  • < v1.3.3: Rust dependency wee_alloc is unmaintained and has open serious issues. Use version >= 1.3.3 to replace it with the default Rust allocator on wasm32 targets.


Copyright (C) myl7

SPDX-License-Identifier: MIT OR Apache-2.0

At your option. Unless otherwise explicitly stated.