README
¶
JSON Benchmarks
This directory contains benchmarking tools to compare JSON against the standard library encoding/json when compiled to WebAssembly using TinyGo.
Build Script
The build.sh script compiles the WASM binaries with different JSON implementations.
Usage
# Build with JSON (default)
./build.sh
# Build with encoding/json (stdlib)
./build.sh stlib
Run the benchmark server
# Start the local server to serve the compiled WASM
go run ./web/server.go
You can then open http://localhost:6060 in a browser to see the benchmark results.
Output
The compiled WASM binary is output to web/public/main.wasm.
The script will display:
- Uncompressed binary size
- Gzipped size (for realistic deployment comparison)
Source Files
clients/tinyjson/main.go- Implementation using JSONclients/stdlib/main.go- Implementation using encoding/json (stdlib)
Both files implement the same functionality to ensure fair comparison.
Performance Results
Last updated: 2026-03-13
Go Benchmark (go test -bench)
| Benchmark | tinywasm/json | encoding/json | Δ allocs |
|---|---|---|---|
| Encode | 648 ns/op 144 B/op 2 allocs | 555 ns/op 80 B/op 1 allocs | +1 |
| Decode | 732 ns/op 157 B/op 5 allocs | 2227 ns/op 376 B/op 8 allocs | -3 |
| RoundTrip | 1510 ns/op 317 B/op 8 allocs | 2576 ns/op 376 B/op 8 allocs | 0 |
Run:
go test -bench=. -benchmem ./tests/...
WASM Binary Size
| Implementation | Binary Size (WASM + Gzip) |
|---|---|
| tinywasm/json | ~27 KB |
| encoding/json (stdlib) | ~119 KB |
Analysis
tinywasm/json is 77% smaller (~27 KB vs ~119 KB) making it ideal for web apps where bundle size matters. While stdlib is faster, tinywasm/json eliminates the reflect package, significantly reducing the final WASM binary size.
Use tinywasm/json when: Bundle size is critical, slow connections, or running in restricted WASM environments. Use Stdlib when: Performance is the only metric and bundle size isn't a concern.
See the main README for detailed benchmark results.
Directories