Performance
Dev-only cost. Production wrappers are no-ops.
Numbers below are from the example app and synthetic ranker runs (Feb 2026). Your app will differ.
Each instrumented variable has a fixed Uint8Array ring. A write overwrites one slot. Filtered heap comparisons show no new Uint8Array constructors between snapshots:
The graph is a sparse Map of edges. Virtual event nodes older than the interaction window are dropped so a long session does not keep every click forever.
A full-heap comparison over a long run can still grow for other reasons (React, DevTools, PerformanceMeasure). This snapshot went 59 MB → 114 MB; almost all of the delta is PerformanceMeasure, not rings:
Treat that as “rings are stable,” not “the tab’s heap never moves.”
- Sampling:
requestAnimationFrame(one bit per frame). - Pairwise work:
requestIdleCallback, and only for variables that wrote since the last pass. - Ranking / full report: when you ask for it (
printBasisReport), not every frame.
benchmarkRanker(), 100 runs:
| Graph | Average per report |
|---|---|
| 18 nodes | ~0.31 ms |
| ~30k nodes | ~27 ms |
30k nodes is a torture graph, not a typical UI. Still on-demand.
Burst in the example app, Chrome local metrics: INP 48 ms (pointer on button.secondary). That is inside Chrome’s “good” band for this recording. It is not a promise about every app.
Per-frame bookkeeping in that kind of burst was in the low tenths of a millisecond when we looked. Re-measure if you change the engine.