Browser WASM size#
Default web builds use the existing min-size Cargo profile for both the agent and the plugin-package validator. It enables opt-level = "z", fat LTO, one codegen unit, aborting panics and stripped symbols. Native default profiles and browser features are unchanged. wasm-opt is not required or downloaded by the normal build.
Measured 2026-10-23#
Sizes are bytes, using the same source and toolchain before/after changing the build profile from default release to min-size:
| Module | Release raw | Min-size raw | Reduction | Min-size gzip | Min-size Brotli |
|---|---|---|---|---|---|
pkg/i_bg.wasm | 2,146,662 | 1,339,525 | 37.6% | 487,806 | 382,707 |
plugin-pkg/validator_bg.wasm | 891,161 | 609,321 | 31.6% | 219,843 | 180,862 |
After adding explicit OPFS concurrency scopes later the same day, the agent is 1,341,287 bytes raw / 488,708 gzip / 383,833 Brotli (+1,762 raw bytes over the initial min-size result); the validator is unchanged. The table above preserves the same-source profile comparison rather than attributing feature changes to compiler optimization.
The subsequent cancellable listing/ZIP and version-checked upload follow-up is 1,342,084 bytes raw / 489,268 gzip / 383,830 Brotli. The validator is unchanged.
Compression figures use gzip level 9 and Brotli quality 11. These are measured compressed payload sizes, not the current development server's transfer sizes: web/serve.mjs sends raw WASM with application/wasm. A deployment server must separately enable gzip/Brotli and preserve the MIME type. PWA caches retain the browser-decoded modules; no persistent workspace data is changed.
Reproduce:
./scripts/build_web.sh
node scripts/measure_wasm.mjsFor a comparison build, use WASM_PROFILE=release ./scripts/build_web.sh, then restore the normal build before publishing. Custom measurement paths can be passed to measure_wasm.mjs. Building for size can trade execution throughput for code size; functional browser tests are not a throughput benchmark.
An additional Binaryen pass was attempted in a separate /tmp build. The wasm-pack Binaryen 117 download failed, so there is no measured or claimed wasm-opt saving in these results. Further reductions would require measuring that pass or changing dependency/feature boundaries; no Unicode search, plugin validation, ZIP, OPFS or model functionality was removed here.