Run with Browser AI · Chapter 11

Run Chapter 11: Latency Decomposition Laboratory

Measure capability inspection, acquisition callbacks, session creation, first output, generation, completion and cancellation as separate browser AI phases.

← Read Cold Starts, Warm Runs and Real Latency
Execution Not inspected
Secure contextUnknown
Top-level pageUnknown
Prompt APIUnknown
AvailabilityNot inspected

Chapter experiment

Cold Starts, Warm Runs and Real Latency

Metrics-only trace

Loading the chapter experiment…

No model output yet.
Inspect the context supplied by this chapter

What this experience knows

This experience is grounded in Chapter 11 and treats latency as a sequence of independently measured boundaries.

Timing boundary

Capability inspection, acquisition callbacks, session creation, time to first chunk, generation, total prompt time, validation and cancellation answer different questions. One duration is never substituted for another.

Protocol boundary

fresh-session means a new session under unknown hidden caches. cold-start-operator-verified is only a label supplied after the operator actually restarted the browser. The API does not attest hidden cache state.

Streaming boundary

Chunks are interface events, not tokens. The laboratory reports chunk count, characters, bytes and character throughput. It does not claim tokens per second.

Statistical boundary

Every raw observation is retained. Medians include sample counts, and fewer than three comparable runs remain a provisional measurement.

Cancellation boundary

An expected AbortError is recorded as an aborted outcome rather than a model failure. If generation completes before the timer or manual abort, cancellation latency remains unmeasured.

Identity boundary

Configuration and model labels are operator-supplied. The browser API does not attest which underlying model produced a response.

This laboratory decomposes browser AI latency instead of reporting one stopwatch value. Label the operating condition, create a measured session, run the first fixture, repeat the identical fixture while warm, and test cancellation separately.

The reviewed replay contributes session creation and progress-callback evidence only. Its missing first-chunk, completion and validation values remain missing.