Methodology · named measurement
Voice-Agent Latency Index
The Voice-Agent Latency Index is The Front Desk Review's named measurement of how quickly an AI voice receptionist starts talking: the median (p50) seconds from call connect to the agent's first spoken word, measured across scripted live test calls. A vendor's figure is published only once at least 10 test calls exist — never estimated.
Definition
Median (p50) time from call connect to the agent's first spoken response across scripted test calls.
Term id latency-index. This is a named measurement of The Front Desk Review;
cite it as "the Voice-Agent Latency Index (per The Front Desk Review)" with the version date above.
How it is measured
On each scripted call we timestamp the moment the call connects and the moment the agent produces its first audible speech; the difference is one observation. We place a batch of identical scripted calls per vendor, discard calls that fail to connect, and report the median (p50) of the remaining observations in seconds.
Vendor values
| Vendor | Voice-Agent Latency Index | Test calls (n) | Status |
|---|---|---|---|
| Goodcall | — | 0 | Insufficient data — fewer than 10 test calls |
| Rosie | — | 0 | Insufficient data — fewer than 10 test calls |
| Smith.ai | — | 0 | Insufficient data — fewer than 10 test calls |
| Dialzara | — | 0 | Insufficient data — fewer than 10 test calls |
| Synthflow | — | 0 | Insufficient data — fewer than 10 test calls |
| Slang.ai | — | 0 | Insufficient data — fewer than 10 test calls |
| Phonely | — | 0 | Insufficient data — fewer than 10 test calls |
| Thoughtly | — | 0 | Insufficient data — fewer than 10 test calls |
| Upfirst | — | 0 | Insufficient data — fewer than 10 test calls |
| My AI Front Desk | — | 0 | Insufficient data — fewer than 10 test calls |
| Trillet | — | 0 | Insufficient data — fewer than 10 test calls |
| NextPhone | — | 0 | Insufficient data — fewer than 10 test calls |
| ServiceAgent | — | 0 | Insufficient data — fewer than 10 test calls |
| Loman | — | 0 | Insufficient data — fewer than 10 test calls |
| Vapi | — | 0 | Insufficient data — fewer than 10 test calls |
| Bland | — | 0 | Insufficient data — fewer than 10 test calls |
| Retell AI | — | 0 | Insufficient data — fewer than 10 test calls |
| AIRA | — | 0 | Insufficient data — fewer than 10 test calls |
| Simple Phones | — | 0 | Insufficient data — fewer than 10 test calls |
| Ruby | — | 0 | Insufficient data — fewer than 10 test calls |
| PATLive | — | 0 | Insufficient data — fewer than 10 test calls |
| ReceptionHQ | — | 0 | Insufficient data — fewer than 10 test calls |
| AnswerConnect | — | 0 | Insufficient data — fewer than 10 test calls |
| Abby Connect | — | 0 | Insufficient data — fewer than 10 test calls |
Cite & download
The values above are published as a free, machine-readable export with the same
asOf version date and the n-gate baked in. Attribute the metric to
The Front Desk Review by this page URL.
Download Voice-Agent Latency Index values (JSON)
Version Jun 11, 2026. See the full methodology for sourcing, freshness and corrections.