Learn Wat - 10 Code Examples & CST Typing Practice Test
WAT (WebAssembly Text Format) is the human-readable, assembly-like syntax used to represent WebAssembly binaries. It allows developers to write, inspect, debug, and understand Wasm modules using a clear, text-based format before compiling to .wasm.
Learn WAT with Real Code Examples
Updated Nov 25, 2025
Learning Path
Understand Wasm basics
Learn WAT syntax
Use wat2wasm / wasm2wat tools
Write low-level modules
Integrate with JavaScript
Skill Improvement Plan
Week 1: WAT syntax, module structure
Week 2: Instructions & stack machine
Week 3: Memory + tables + imports
Week 4: Host integration & debugging
Week 5: Performance tuning & binary inspection
Interview Questions
What is WAT and why does it exist?
Explain WebAssembly’s stack machine model.
How do you define and export a function in WAT?
What is linear memory in WebAssembly?
How does wat2wasm differ from wasm2wat?
Cheat Sheet
(module ... ) - define module
(func (param i32) (result i32) ... )
(memory 1) - 1 page (64KiB)
i32.load / i32.store - memory ops
export - expose functions
Books
The WebAssembly Specification
WebAssembly: The Definitive Guide
Understanding WebAssembly by Example
Handcrafted WebAssembly
WebAssembly Internals: A Deep Dive
Tutorials
Writing your first WAT module
Memory management in WAT
Import/export patterns
Debugging Wasm using wasm2wat
Building micro-libraries in WAT
Official Docs
https://webassembly.github.io/spec/core/text/
https://webassembly.org/docs/
Community Links
WebAssembly Community Group
WABT GitHub
Mozilla WebAssembly Docs
StackOverflow WebAssembly
WebAssembly Discord
Community Support
W3C WebAssembly Community Group
Mozilla WebAssembly docs
WABT GitHub
StackOverflow Wasm tag
WebAssembly Discord
Frequently Asked Questions about Wat
What is Wat?
WAT (WebAssembly Text Format) is the human-readable, assembly-like syntax used to represent WebAssembly binaries. It allows developers to write, inspect, debug, and understand Wasm modules using a clear, text-based format before compiling to .wasm.
What are the primary use cases for Wat?
Learning WebAssembly internals. Debugging or inspecting Wasm modules. Creating tiny hand-crafted Wasm binaries. Reverse engineering WebAssembly. Testing Wasm instructions or host bindings
What are the strengths of Wat?
Extremely lightweight and minimal. Perfect for learning WebAssembly internals. Direct control over Wasm structure and instructions. Readable and easy to experiment with. Useful for debugging compiler output
What are the limitations of Wat?
Not suitable for large-scale application development. No high-level abstractions (loops, structs, variables). Verbose for anything beyond small modules. Hard to maintain manually. Manual memory management required
How can I practice Wat typing speed?
CodeSpeedTest offers 10+ real Wat code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.