kitesurf · bench

Viewing archived run 2026-05-25 · commit caf5678. 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 2026-05-25 · 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)

2026-05-25.md 2026-05-25.json history.json badge.svg

# kitesurf bench report — 2026-05-25

commit: `caf5678` · backends: kitesurf, container · endpoints: screenshot, html · runs/combo: 5 (+ 2 warmup)
target: https://kitesurf-bench.rendering.cfdata.org

> rerun with concurrent-producer wallMs fix

## Summary (median wall time)

| Page | kitesurf/screenshot | kitesurf/html | container/screenshot | container/html |
|---|--:|--:|--:|--:|
| Example Domain | 526ms | 520ms | 274ms | 154ms |
| Hacker News | 662ms | 653ms | 672ms | 480ms |
| Cloudflare Developer Docs | 760ms | 746ms | 645ms | 449ms |
| The Cloudflare Blog | 1507ms | 1188ms | 741ms | 514ms |
| Wikipedia Portal | 633ms | 658ms | 608ms | 369ms |
| TodoMVC · JavaScript ES6 | 581ms | 545ms | 358ms | 183ms |
| TodoMVC · React | 567ms | 438ms | 365ms | 218ms |
| TodoMVC · Vue | 585ms | 572ms | 352ms | 202ms |
| TodoMVC · Angular | 599ms | 597ms | 349ms | 243ms |
| TodoMVC · Preact | 558ms | 571ms | 348ms | 188ms |

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