See it before the open house.

In a hot market the good listing is gone by the weekend, and the portal's own email alerts have a habit of arriving on their schedule, not the market's. Agents watch the feed all day. Everyone else finds the perfect place on day four, after the offer deadline.

modsignal watches a saved-search results page or a specific listing and alerts you on what you actually care about: new matches under your ceiling, a price cut, a status change from active to pending — on any portal, or a single agency's site the big portals don't cover.

Alerts name the change — new 3-bed at $612k, price dropped $23k, status now pending — with the before and after, so you can decide from your phone whether to call. Semantic fits search pages, which constantly reorder and re-render; exact-diff fits a single listing you're negotiating on, where every edit matters.

House hunters typically run one monitor on their main search and one per shortlisted listing, checking every few hours. When the right one posts on Thursday night, you're the Friday-morning viewing, not the Sunday open house.