Web Assembly Tools

Inspecting

WebAssembly Code Explorer: A simple binary explorer with neat binary code highlighting.
Weave: 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) : 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 | Source: Converts WebAssembly binaries to C. Similar to wasm2c.
wasp: 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: List the imported, exported, and private function symbols defined within a .wasm binary.

Twiggy | repo: Code size profiler, analyzes a binary's call graph.
Manticore | repo, article: Symbolic execution of WebAssembly binaries.
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.

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: 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.

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.

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

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

Tags: platform tool web assembly

Last modified 06 December 2025