About
A script, a database and an email
OpenSein is your digital rental search agent. We follow public rental listings and help you search and prepare with digital guidance and practical knowledge. If you get stuck, email the team. You register and respond directly with the provider.
Nobody gets priority
One queue, in order of arrival. There is no column to sort a tier on and no button for it in the admin panel.
Only what is already public
The same pages you can open yourself. Title, features and a link to the source. Nothing more.
You are not the product
No third-party analytics, no ad network, no data going anywhere else. What we count, we count ourselves, and your behaviour only if you say yes.
On this page
The team behind OpenSein
We read your application.
Now we send you an alert.
We are estate agents, property specialists and developers. For years we sat on the other side of the house hunt. We assessed applications, held viewings and signed thousands of rental contracts.
There we saw house hunters pay to come across better, while it often made little difference. That is why we built OpenSein: alerts, digital guidance and preparation based on our practical knowledge, so you know where and how to respond yourself.
Less refreshing. More time for your life.
- Thousands of rental contracts signed
- Hundreds of homes sold
- Every working day still busy with new listings
Other search platforms, loosely paraphrased:“We were looking for a home ourselves. It was hard. So we started a platform.”Read on
That is like having been in an ambulance once and thinking as you step out: “Right. I'm starting a hospital.” Add a website, put a subscription on it and let the patients come. After all, you have been on the stretcher yourself.
Having lived through a problem is not expertise. Certainly not if you then charge money for the solution.
We came up with the idea while we were doing the viewings, assessing the applications and signing the rental contracts. At our desks sat house hunters who had neatly followed every tip. The personal letter. The extra phone call. The paid trick. Lots of effort, little difference.
We wanted to do something about that. With OpenSein we use our expertise to help you: knowing what makes sense, leaving aside what adds nothing and seeing in time where you can reply.
For years we opened the door for you. So we also know how to get your foot in the door.
Why we built OpenSein About our sourcesRead our letter
Why
In practice, free-sector rentals are handed out in order of application. Which means the outcome depends largely on whether you happened to be looking at the right moment. That can be automated, so it should not cost anyone their evening.
What OpenSein is, then: a crystal ball on fibre. A clairvoyant with zero ping. It knows nothing before the landlord does, it just knows it at the same moment and does not forget to pass it on.
The principle everything hangs on
Paying never buys time. Everyone gets the same alert in the same round. The paid tier sells precision and reach: more providers, filters, several channels, and help after the alert. Never priority.
That is not a sentence in the terms but a decision in the code: delivery sorts on the moment something entered the queue, and there is no column it could sort a tier on. The admin panel has no button for it either. The day that principle is dropped, OpenSein is exactly the commercial aggregator it exists to be an alternative to.
The awkward part
No non-public information is used. At every provider, OpenSein reads exactly the same public listing data as any visitor to their site: no internal connection, no head start, no arrangement behind the scenes. Where a provider publishes its own API we use it; where it does not, we read the public page. Never through an aggregator, always at the source.
To do that, the service makes hundreds of thousands of requests per day: to providers, in the database and to the channels. The figure is on the status page, with the breakdown next to it.
And one rule we impose on ourselves: no single provider may dominate the paid listings. That is not a promise but a number. It sits in the admin panel and is measured monthly. As soon as one source gets too large, the answer is to connect more sources, not to send fewer alerts.
And the name
No, this is not an OpenAI product. The name is a pun on the Dutch word sein: the light that turns green when something frees up. We are aware of the association; we are also aware that a disclaimer does not undo brand confusion. A second name is ready and waiting.
Part of what is earned here goes to the red panda. That has nothing to do with renting. That is exactly the point.
What we do not do
- Apply on your behalf, or register you anywhere.
- Copy advert text or photos. Title, features and a link to the source; nothing else.
- Sell your data or use it for advertising. There is no third-party analytics on this site and no ad network: we count for ourselves, on our own server, and behaviour only with your consent.
- Hammer the sources. A calm frequency, an identifiable user agent, and an address where a landlord can reach us.
Contact
post@opensein.nl. A landlord who would rather not be in the feed? We will take your source out as soon as we can.