Awesome WebAssembly Tools

A collection of useful, language-agnostic WebAssembly development tools.

👉 Contributions are welcome! Please read the contribution guidelines. 😎

Inspecting

• WebAssembly Code Explorer | online tool
  A simple binary explorer with neat binary code highlighting.

• Weave | online tool
  Another simple binary explorer.

• wasm-opt | part of Binaryen

  • Color output of s-expression format:
    wasm-opt --print test.wasm
  • Plot the callgraph using Graphviz:
    wasm-opt --print-call-graph test.wasm | dot -Tpng -o callgraph.png
  • Dump DWARF debug info sections:
    wasm-opt --dwarfdump test.wasm
  • Print function metrics:
    wasm-opt --func-metrics test.wasm

• wasm-decompile | part of WABT, article
  wasm-decompile decompiles a wasm binary into readable code. It generates output that tries to look like a "very average programming language" while still staying close to the wasm it represents.

• wasmdec | repo, online tool
  Converts WebAssembly binaries to C. Similar to wasm2c.

• wasp | repo
  Generate callgraphs, CFG and DFG graphs for wasm functions.

• wasm-objdump | part of WABT
  Print low-level details about a .wasm binary and each of its sections.

• wasm-nm | repo
  List the imported, exported, and private function symbols defined within a .wasm binary.

• Modsurfer | home, repo
  Diagnostics and auditing tool for searching, browsing, validating, and investigating WebAssembly modules and components.

Static analysis

• Twiggy | repo
  Code size profiler, analyzes a binary's call graph.

• Manticore | repo, article
  Symbolic execution of WebAssembly binaries.

• Owi | docs, repo
  Framework for WebAssembly analysis and manipulation, with a focus on practical symbolic execution.

• Octopus | repo
  Security analysis framework for WebAssembly modules and Smart Contracts.

• Wassail | repo
  A toolkit to perform both lightweight and heavyweight static analysis of WebAssembly modules.

• wasm-opcodecnt | part of WABT
  Count wasm opcode usage statistics.

Manipulating (optimization, transformation, instrumentation)

• wasm-opt | part of Binaryen

  • Transform binary for asynchronous execution (read more in this article):
    wasm-opt test.wasm --asyncify -O3 -o asyncified.wasm
  • Instrument binary for dynamic execution tracing:
    wasm-opt test.wasm --instrument-memory --instrument-locals --log-execution -o instrumetred.wasm

• wizer | repo
  Don't wait for your Wasm module to initialize itself, pre-initialize it! Wizer instantiates your WebAssembly module, executes its initialization function, and then snapshots the initialized state out into a new WebAssembly module.

• wasm2c | part of WABT, article 1, article 2
  Takes a WebAssembly module and produces an equivalent (and runnable) C source and header.

• wasm-snip | repo
  Replaces a WebAssembly function's body with an unreachable.

• wasmonkey | repo
  Magically turns exported WASM functions into imported functions.

• wasm-meter | npm, repo
  Injects metering into webassembly binaries. This counts computation time for a given program in units of gas (and allows limiting it).

• CROW | repo
  The Wasm superdiversifier. It takes C source code or LLVM bitcode as input and generates several functionally equivalent, but diverse Wasm binaries.

• watr | repo, npm, demo
  Light and fast WAT compiler for compiling, parsing, printing, formatting, optimizing, and polyfilling WebAssembly text.

Component Model and WIT

• jco | docs, repo
  JavaScript-native toolchain for working with WebAssembly Components, including transpiling components to ES modules and creating components from JavaScript.

• ComponentizeJS | repo
  Tool for turning JavaScript modules into WebAssembly components.

• wit-bindgen | repo
  Guest language bindings generator for WIT and the WebAssembly Component Model.

• wac | repo, docs
  WebAssembly Compositions tool for composing components together from the command line or from .wac composition files.

• cargo-component | repo, crate
  Cargo subcommand for building Rust WebAssembly components from WIT worlds.

• wkg, wasm-pkg-tools | repo, crate
  Tools for fetching and publishing WebAssembly components and WIT packages to OCI or Warg registries.

• WASI-Virt | repo
  Virtualization component generator for WASI Preview 2 APIs, useful for encapsulating or restricting component access to host capabilities.

Dynamic analysis (tracing, profiling)

• wasm3-strace | wapm, repo
  Structured, seamless tracing of arbitrary WebAssembly/WASI execution.

• Wasabi | home, repo
  "WebAssembly analysis using binary instrumentation", a dynamic analysis framework.

• wasmsign2 | repo
  A tool to add and verify digital signatures to/from WASM binaries.

• swam | repo
  A WASM interpreter with advanced tracing capabilities.

Editing

• wasm-language-tools | home, repo
  Language server and formatter for WebAssembly Text Format, with completion, diagnostics, navigation, inlay hints, and call hierarchy.

• Hexana | docs, repo
  WebAssembly and binary analysis toolkit for JetBrains IDEs and VS Code, including structured .wasm inspection, WAT and WIT support, and run/debug integrations.

• vscode-wit | repo
  Visual Studio Code extension for WIT, with syntax highlighting, validation, formatting, bindings generation, and component inspection.

Source-level debugging

• Chrome DevTools | article

• LLDB | article

• wasminspect | repo
  An interactive and self-contained debugger for WebAssembly/WASI.

Tool development

• Tool Conventions | docs
  Documents describing conventions useful for coordinating interoperability between wasm-related tools.

• Binaryen | repo
  WebAssembly compiler and toolchain infrastructure with tools for parsing, emitting, optimizing, interpreting, reducing, merging, and compiling WebAssembly.

• WABT | repo
  The WebAssembly Binary Toolkit, a suite of command-line tools for converting, inspecting, validating, and manipulating WebAssembly binaries and text.

• Javy | repo
  JavaScript-to-WebAssembly toolchain based on QuickJS, producing compact WASI modules.

• wasm2json, json2wasm | npm, repo
  A small toolkit for converting wasm binaries into json and back. Incredibly helpful for experimenting and creating your own transformations.

• walrus | repo
  Rust library for performing WebAssembly transformations in a robust and ergonomic fashion.

• waffle | repo, crate
  Rust SSA IR framework for WebAssembly analysis and Wasm-to-Wasm transforms.

• wasp | repo
  C++ library designed to make it easy to work with WebAssembly modules.

• Binaryen.js | repo
  A port of Binaryen to the Web, allowing you to generate WebAssembly using JavaScript.

• wasm-tools | repo
  Rust tooling for low-level manipulation of WebAssembly modules.
  wasm-smith test case generator is of particular interest.
  wasm-shrink shrinks a Wasm file while preserving an interesting property (such as triggering a bug).

• wasm-debug | repo, crate
  A runtime-independent Rust library that provides functionality to read, transform, and write DWARF section.

• witx-codegen | repo
  A code generator to access WebAssembly standard APIs from different programming languages. Can also generate documentation.

• Articles

  • Fuzzers & Reducers as Productivity Tools

Application frameworks and deployment

• Extism | home, repo
  Cross-language framework for building WebAssembly-based plugin systems with host SDKs and guest PDKs.

• Spin | home, repo
  Framework and CLI for building, running, and distributing serverless WebAssembly applications.

• wasmCloud, wash | docs, repo
  Cloud-native platform and CLI for developing, building, publishing, and running WebAssembly components.

• SpinKube | home, repos
  Kubernetes-native stack for deploying and operating Spin-based WebAssembly workloads.

• runwasi | docs, repo
  Containerd shim infrastructure for running WebAssembly workloads through containerd and Kubernetes.

Other

• WebAssembly Opcode Table | docs

• WebAssembly Feature Status | docs
  Matrix tracking WebAssembly feature support across popular browsers, standalone runtimes, and tools.