kitesurf · bench

Viewing archived run 2026-07-05 · commit be11786. View latest →

Backend comparison — median wall time

One grouped bar per page, one bar per backend. Bar height = median wall time from the orchestrator's performance.now() span. Hover a bar for median/p95/p99. Missing or all-errored cells render as a thin grey stub.

Backend comparison — median backend CPU time

Server-side CPU per call. Kitesurf reports $workers.cpuTimeMs from Workers Observability; container reports Node-side CPU via timing headers. Browser-run doesn't expose a CPU counter — bars render as a grey stub.

Backend comparison — median memory

Per-page memory at end of render. The two backends report different things — bars are directionally comparable, not strictly apples-to-apples.

• kitesurf: kitesurf_core wasm linear memory size (WebAssembly.Memory.buffer.byteLength via Kitesurf.getMemoryStats). The wasm heap covers everything the renderer uses — DOM, parley, vello, stylo, image decode, screenshot raster — but it's a coarse high-water proxy: Rust's dlmalloc grows in chunks and doesn't release back to the OS, so the reading reflects peak demand rather than bytes-in-use. Per-render: each navigate gets a fresh isolate.
• container: per-page memory from CDP Runtime.getHeapUsage (the same RPC DevTools' Memory panel uses), captured right after the page's load pipeline finishes — before V8's idle-time GC compacts the arenas. The value is totalSize (V8 heap arena) + embedderHeapUsedSize (Blink's native state: DOM, layout, image cache, style data) + backingStorageSize (ArrayBuffer / typed-array backings), matching DevTools' "Total JS heap size" for a live page. Doesn't cover GPU buffers or other renderer state outside Blink's embedder heap.

In short: kitesurf overcounts (high-water peak across the whole renderer); container undercounts (JS heap only). The truth for either backend lives somewhere between the two columns.

Run 2026-07-05 · per-metric tables

Same layout as npm run bench: per endpoint, tables for wall, cpu, mem. Each backend's median/p95/p99 side by side. ks = kitesurf, br = browser-run, ct = container. — = backend doesn't report this metric. err = every recorded run for that combination errored. See the memory chart's caption above for the per-backend metric semantics.

History

Archived report (markdown)

2026-07-05.md 2026-07-05.json history.json badge.svg

# kitesurf bench report — 2026-07-05

commit: `be11786` · backends: kitesurf, container · endpoints: screenshot, html · runs/combo: 5 (+ 2 warmup)
target: https://kitesurf-bench.rendering.cfdata.org

> boa eval-less runtime — run page JS (Runtime.evaluate + dynamic import) without V8 code-gen-from-string @lduarte

## Summary (median wall time)

| Page | kitesurf/screenshot | kitesurf/html | container/screenshot | container/html |
|---|--:|--:|--:|--:|
| Example Domain | 846ms | 811ms | 437ms | 215ms |
| Hacker News | 1207ms | 1042ms | 828ms | 826ms |
| Cloudflare Developer Docs | 2680ms | 2709ms | 1008ms | 760ms |
| The Cloudflare Blog | 2166ms | 2293ms | 1001ms | 837ms |
| Wikipedia Portal | 1645ms | 1468ms | 915ms | 677ms |
| Der Spiegel | 1688ms | 1973ms | 1790ms | 1739ms |
| El Mundo | 3013ms | 2026ms | 1590ms | 1195ms |
| TodoMVC · JavaScript ES6 | 1266ms | 1329ms | 493ms | 343ms |
| TodoMVC · React | 1384ms | 811ms | 965ms | 388ms |
| TodoMVC · Vue | 1331ms | 1392ms | 564ms | 801ms |
| TodoMVC · Angular | 1389ms | 821ms | 868ms | 706ms |
| TodoMVC · Preact | 785ms | 758ms | 522ms | 643ms |

Notes:

- Values are run medians across recorded runs. p95 and min/max are in the JSON.
- Backends are dispatched from inside the `kitesurf-bench` worker via RPC bindings: `env.KITESURF.fetch(/screenshot|/html)` for kitesurf (service binding to the engine), `env.BROWSER.quickAction('screenshot'|'content', …)` for browser-run (Browser Rendering RPC), and `env.CONTAINER_HOST.fetch(…)` for container (sibling worker fronting its container backend). Wall time is the orchestrator's `performance.now()` span; `backendWallMs` / `backendCpuMs` in the JSON come from Workers Observability (kitesurf) or container-side timing headers (container). None of the measurement paths traverse the public internet.
- A cell shows `—` when every recorded run for that combination errored. See `rows` in the JSON for individual failure messages.

bundle built 2026-07-11T17:46:18.286Z