WASM Module Explorer

WebAssembly (WASM) is a binary instruction format for a stack-based virtual machine. It is designed as a portable compilation target for programming languages such as C, C++, Rust, and Go, enabling high-performance code to run in web browsers and server runtimes at near-native speed. WASM modules are compact, fast to decode, and sandboxed for security.

WAT is the human-readable text representation of a WebAssembly module. While .wasm files are compact binary files, WAT uses S-expression syntax — parentheses-nested declarations like (module (func ...)) — to express the same structure. WAT is primarily used for debugging, learning, and hand-authoring small WebAssembly modules. You can convert between .wasm and .wat using the wasm2wat and wat2wasm tools from the WebAssembly Binary Toolkit (WABT).

Exports are items (functions, memories, globals, tables) that a WASM module exposes to the host environment — a JavaScript runtime, another module, or a WASI host. Imports are items that the module requires from the host before it can run. For example, a module might import a 'log' function from 'env' and export an 'add' function that JavaScript can call. The host must supply all declared imports or instantiation will fail.

A WebAssembly binary is composed of numbered sections: type (function signatures), import, function (index → type mapping), table, memory, global, export, start (entry-point), element (table initializers), code (function bodies), and data (memory initializers). For .wasm binary files this tool scans the actual section IDs in the binary. For WAT text input it infers sections from the declarations present in the source.

No. All analysis runs entirely in your browser using the native WebAssembly JavaScript API — specifically WebAssembly.compile(), WebAssembly.Module.exports(), and WebAssembly.Module.imports(). Your file never leaves your machine. This also means the tool requires a modern browser with WebAssembly support (Chrome 57+, Firefox 52+, Safari 11+, Edge 16+).