The trick to finding out when a listing was posted on Idealista

Idealista doesn't want you to know when that property was listed

A property has been on Idealista for months. The price drops, goes up, drops again. The listing looks new, but it's been there for two years. And there's no official way to check. The first publication date of a property on the major portals —Idealista and Fotocasa— is one of those pieces of data that exist but aren't shown, and anyone searching for a home hits a wall: the website only keeps the last renewal.

The question that started it all was simple: can you find the original date of a listing? The short answer is that the portal doesn't provide it. The long answer involves looking under the hood.

Why the portal only shows the latest date

The mechanism is well known to anyone who has published on these platforms: the advertiser can renew the listing periodically without deleting it or creating a new one. Each renewal updates the visible date. The result is a shop window where everything looks freshly baked. For the portal, this selective amnesia isn't a flaw: it's the product. Showcasing new listings is part of the business, and a property that's been up for 18 months doesn't sell the same as one that just came in.

Some have tried to track the history with Archive.org, without success: the search tool doesn't work on the saved snapshots. The DIY alternative is to save the listing to favorites and manually note the date and price on the day you found it. Not segarro, but it works.

The listing ID as a time clue

The most promising route isn't in the interface, but in the URL. Listing IDs are consecutive and, according to those who have trinc the trail, lower numbers correspond to older listings. When a property is rented out, the listing disappears; if it becomes available again, it reappears with the same ID. In other words: the portal keeps its internal memory even though it hides it on screen.

That opens the door to placing a listing in time by comparing its number with others of known date. It's not an exact science, but it's the closest thing to a clock the system offers.

Tools that do reconstruct the history

Outside Spain there's a precedent that shows the problem is one of will, not technique. In the UK, a Firefox add-on called Property Bee adds the history of price rises and drops, plus description changes, to RightMove listings. It works collaboratively: everyone browsing with the plugin active anonymously reports the details of the listings they see to a central database, which returns the accumulated information to everyone else.

In the Spanish market, the Oportunista extension lets you see when a listing was posted and its price history. And on Fotocasa, according to those who have tried it, the listing page does show how long something has been advertised.

The data they don't want to publish

The underlying explanation is commercial. Professional advertisers pay to appear, and the portal has no incentive whatsoever to make it easy to filter between private sellers and agencies, or to reveal a property's real age. The information asymmetry is what sustains the business.

Hence the recommendation that circulates among the most experienced: if you have a specific area in mind, test the market on the ground. Shops, doormen, notices on lampposts. Anything that doesn't go through an agency's filter still holds the bargains.

In the end, the publication date of a listing on Idealista is a piece of data the portal keeps, the ID gives away, and the interface hides. The question is no longer whether you can find out, but how much the market is willing to let you know.