Published 2026-07-22 · data as of 2026-07-22 · by Flatscout
Portal 'instant' emails are dispatched in batch cycles. We measured our own real-time pipeline end to end: median 8.6 minutes from listing to alert, and delivery itself takes seconds.
Every UK portal offers saved-search alerts, and Rightmove's fastest setting is even labelled 'Instantly'. But portal alert emails are dispatched in batch cycles rather than the moment a listing goes live — users routinely report gaps of several hours between a listing appearing and the 'instant' email arriving. Because Flatscout timestamps both events — when we first see a listing anywhere, and when an alert for it is created — we can publish the number the portals don't: the actual end-to-end speed of a real-time alert.
For context on who's measuring: Flatscout is a cross-portal property alert service — it aggregates live listings from Rightmove, Zoopla, SpareRoom and 70,000+ UK agents onto one map, matches new listings against saved searches every 60 seconds, and delivers alerts by email, WhatsApp or Telegram. Twice-daily and weekly alerts are free; the real-time tier measured in this article is a paid add-on. How it works is on the alerts page at flatscout.co.uk/alerts.
We took every real-time alert Flatscout generated over the last 90 days — 22,582 of them — and measured the gap between the listing first being detected on any source (Rightmove, Zoopla, SpareRoom or an agent's own feed) and the alert batch being created for a matching saved search. This includes all of our own overhead: crawl detection lag, enrichment, and the 60-second matching cycle.
| Measure | Value |
|---|---|
| Fastest quarter (25th percentile) | 4.3 minutes |
| Median | 8.6 minutes |
| Slowest quarter starts (75th percentile) | 14.2 minutes |
| 90th percentile | 26.3 minutes |
| Alerts within 15 minutes | 76.8% |
| Alerts within 1 hour | 97.3% |
Once a listing matches a search, the delivery leg is nearly instant: the median dispatch time from match to the message being handed to email, WhatsApp or Telegram is 2.5 seconds (90th percentile: 6.7 seconds). Effectively all of the latency budget is spent detecting the listing — which is why crawl frequency, not notification plumbing, is what separates alert services.
For the median rental — which takes about four weeks to let — no. But the market has a fast tail: 6.2% of the 68,350 lets we've tracked went from first listing to Let Agreed within 7 days, and that fast tail skews heavily toward underpriced and high-demand stock — exactly the listings worth competing for. Agents work enquiries in arrival order, so hearing at minute 9 versus hour 6 decides whether your enquiry is on top of the pile or under fifty others.
There's also a structural timing effect: 79% of new listings go live between 8am and 6pm, peaking around 11am. If your alerts arrive as an evening digest, you are systematically half a working day behind on almost everything — see our analysis of when new listings go live.
'First seen' is the timestamp Flatscout's continuous crawl first observed the listing on any source; it carries our own detection lag, so the true listing-to-alert gap is if anything slightly shorter than reported. 'Alert created' is the notification batch's creation time for saved searches set to real-time frequency. Delivery timings are measured from batch creation to the per-channel send timestamp in our delivery log. All data from Flatscout production, 90 days to 22 July 2026.