One Apartment, Three Portals, Three Prices: Why? 24,835 Ads

In four Brazilian municipalities, on 27 July 2026, 24,835 active rental ads across ZAP Imóveis, OLX, ImovelWeb, Chaves na Mão and QuintoAndar described 13,806 distinct homes. 53.8% of those homes were advertised on two or more of the five portals, and no single portal showed even half of them. The duplication in this article's title is real. The three prices mostly are not: among the homes advertised on more than one portal, 93.8% carried exactly the same rent on every portal that listed them. What the data shows is not five marketplaces pricing the same apartment differently. It is the same advertiser putting one home on several portals at once, plus a small minority of cases where the gap between two ads for one home is large enough to change what you can afford.

Two things in that finding change what you do next. First, the money: in the 6.2% of cases where two ads for one home disagreed on the rent, the middle gap was R$ 140 — the median, meaning the middle case once every gap is lined up from smallest to largest, which is not the same as the average. The tail is where the damage is: one house in this sample was advertised at R$ 2,600 on two portals and R$ 4,500 on a third. Second, the move: if you are going to open a second portal, choose it deliberately. 96.23% of the homes ZAP listed in this sample were also on OLX, so opening those two is close to opening one site twice. Pair one of them with ImovelWeb, QuintoAndar or Chaves na Mão instead, and the second look reaches homes the first site never showed you.

Every guide to renting in Brazil, ours included, gives the same advice: before you trust a listing, look for the same home on another portal. Our own fake-listing guide builds a whole check on it. It's sound advice, and for a long time nobody had published how often the same home actually appears twice, which pairs of sites it appears on, or how far the prices drift apart when it does. This page is that measurement.

A word on who is talking. RemRent is a rental-search aggregator being built for Brazil: one search across six portals — the five measured here plus Viva Real, from the same Grupo OLX family — with the duplicates collapsed. It isn't open, nothing is on sale here, and this measurement was only possible because the base of listings we have already collected for that product exists. We have an obvious interest in the answer being large, so here is the short version of how we got it: we joined ads by their photographs, never by their price — and the thresholds, the sample, the date and every known bias are set out in full at the bottom. Every share we publish is a floor — a minimum. Every error our method can make pushes the number down, never up.

How often the same home appears on more than one portal

Those 24,835 ads collapsed into 13,806 distinct homes, roughly 1.8 ads per home, and 7,433 of them — the 53.8% above — were advertised on two or more of the five portals. 1,864 homes, 13.5%, were on three or more. 179 homes, 1.3%, were on four or more. Read the other way: a renter working through one portal's results in these four municipalities is looking at a list in which more than half the homes are also sitting on at least one other site.

The share is not uniform. In Osasco it was 46.84% of 4,859 homes, in Niterói 46.71% of 2,507, in Canoas 61.66% of 3,685 and in São Leopoldo 62.21% of 2,755. That is a wide band across four ordinary municipalities, and it is the main reason we treat the combined 53.8% as a finding about this sample, not about Brazil.

The combined figure also hides the more useful result. Duplication is not spread evenly across the ten possible pairings of five portals. It is concentrated in two of them.

Each of the last two rows covers several pairings at once, so there is no single shared-homes count to print. We show the absolute number only where one pairing is large enough for it to mean something, and QuintoAndar's remaining pairings run between 0.03% and 0.10%.

ZAP and OLX show much the same homes. 6,131 homes were on both. Of everything ZAP listed in the sample, 96.23% was also on OLX; of everything OLX listed, 92.18% was also on ZAP. For a renter, opening those two sites is close to opening one site twice. That's not a surprise once you know that the five brands are two corporate groups and one independent, and that Grupo OLX's own terms of use let an ad be republished across its sites. What the measurement adds is the size of that effect.

A third of QuintoAndar's homes are also on ImovelWeb. 1,009 homes appeared on both: 34.15% of everything QuintoAndar listed and 24.23% of everything ImovelWeb did. The two belong to the same company — Grupo QuintoAndar — so the overlap is not a surprise. What the measurement adds is how big it is. In every other direction QuintoAndar's homes stay where they are: between 0.03% and 0.10% of them reached ZAP, OLX or Chaves na Mão.

No portal showed even half of this sample. Set each portal against all 13,806 homes and you get the coverage below, alongside the share of homes that appeared on that portal and nowhere else.

Data as of 27 July 2026, four municipalities, five portals, 13,806 distinct homes identified by matching their photographs. Shares are of the sample, not of national inventory, and each is a floor for the reasons set out further down.

The exclusive column is where the practical damage sits. The two most-visited brands add almost nothing to each other, while the two portals with the smallest share of the sample hold the largest blocks of homes that exist nowhere else: 17.41% of all homes were on ImovelWeb only, and 14.09% on QuintoAndar only, close to two thirds of everything QuintoAndar published. QuintoAndar also screens applicants the hardest, so the homes a newcomer is least likely to be approved for are also the homes least likely to appear anywhere else. That is worth knowing before you plan a rental search from outside the country.

The price spread on identical homes

This is where the premise of the headline breaks. Of the 7,433 homes advertised on more than one portal, only 462, that is 6.2%, carried more than one price. The remaining 93.8% were advertised at exactly the same rent everywhere they appeared. Cross-portal duplication in this sample is overwhelmingly republication of one advertiser's ad, not five markets competing on price for the same set of keys.

The ZAP and OLX pair makes the mechanism visible: of the 6,131 homes on both, 6,027 carried an identical rent. The same holds on the full monthly cost, not just the headline rent. Portals differ in what they print in large type — some show the rent on its own, others the rent plus the monthly building charge (the condomínio, the shared upkeep bill every flat in a building pays) and the yearly municipal property tax (the IPTU). So we ran the comparison on that combined figure as well, and there too the middle case was a gap of exactly zero. The headline rent behaves the same way.

Where prices do differ, though, they differ hard. Among those 462 homes the median gap between the cheapest and the most expensive ad was R$ 140, or 6.1% of the lower rent. A quarter of those gaps were 14.29% or wider. The widest 5% all ran above 71.65%, and the single widest hit 228%. A house in Niterói was advertised at R$ 2,600 on two portals and R$ 4,500 on a third, a difference of 73.1% for the same home. A one-bedroom apartment in Osasco appeared on all five portals at once, at R$ 1,900 on three of them, R$ 2,125 on the fourth and R$ 3,110 on the fifth, a spread of 63.7% between the cheapest and the most expensive ad for one home.

The direction of those gaps is not random either. Where ImovelWeb and QuintoAndar disagreed on a shared home, ImovelWeb was the more expensive one in 134 cases against 34 the other way. Chaves na Mão came in below OLX and ZAP between three and four times as often as it came in above them. So the disagreements, rare as they are, lean the same way each time — what you would expect from stale copies and differing fee conventions, not from genuine competition.

For a renter the useful read is this. Checking a second portal will confirm the price you already saw about fifteen times out of sixteen. The sixteenth is worth the two minutes on its own, because that's where the four-figure differences live.

All of this is about one home's price across portals, not about the price level itself. If the question you actually have is the other one — what a home asks in your city in the first place — we measured that separately, across thirty cities and seventeen São Paulo districts: how much rent costs in Brazil.

How to check a listing yourself in two minutes

Everything above was done by machine, across our whole collected set of ads. The same check works by hand on a single listing, and the measurement suggests how to spend the two minutes.

• Choose the second portal deliberately. Opening ZAP and OLX for the same home is close to opening one site twice: 96.23% of ZAP's homes in this sample were also on OLX. Pair one of those two with ImovelWeb, QuintoAndar or Chaves na Mão, and the check actually reaches different homes.
• Search on what travels between portals. Ad text is rewritten from site to site; the photographs and the neighborhood stay constant, which is why we joined ads by their pictures rather than their words. Search the neighborhood plus the size and the approximate price, then compare the images.
• Compare totals, not headlines. Portals differ in whether the number in large type is the rent alone or the rent with the condomínio and the IPTU on top. On the combined figure the duplicate ads in our sample agreed almost perfectly, so if two copies of one home disagree on the total, that is a real difference, not a formatting one.
• Do not treat a single copy as a warning by itself. 46.2% of the homes in this sample were on exactly one portal. Appearing in only one place is the normal condition of nearly half of genuine listings, so absence elsewhere is a reason to look harder, not a verdict.
• When you find copies, expect them to agree. Roughly fifteen times out of sixteen they'll show the same rent. A copy that disagrees is worth a direct question to both advertisers, and the answer is usually a stale ad or a different definition of what the price includes.

What this means for the fake-listing checklist

The cross-portal check is the strongest single step in our guide to spotting a fake listing, and this measurement calibrates that step; it does not replace it. Two corrections come out of the data.

First, the step works, but not universally. Slightly more than half of genuine homes here could be found on a second portal, so a match is meaningful confirmation. The reverse is not: with 46.2% of real homes on one portal only, failing to find a second copy does not mark a listing as fake. Treat a no-match as a prompt to verify ownership another way, not as proof.

Second, the checklist leans harder on price differences than the data supports. Two honest ads carry the same rent 93.8% of the time, so a mismatch really is unusual — but unusual is not the same as fraudulent. The largest gaps we measured, including the Niterói house at R$ 2,600 on two sites and R$ 4,500 on a third, were between ordinary ads on established portals with no scam involved. A lower price on another site does not identify the fake. What identifies the fake is the demand for money before a viewing, and no measurement changes that.

What we measured, and how

The method, in one paragraph. Everything above comes from the pile of listings RemRent has already collected: a snapshot taken on 27 July 2026 of 24,835 active rental listings across five Brazilian portals (ZAP Imóveis, OLX, ImovelWeb, Chaves na Mão and QuintoAndar) in four municipalities — Osasco in São Paulo state, Niterói in Rio de Janeiro, and Canoas and São Leopoldo in Rio Grande do Sul. Two ads are joined into one home on the strength of their photographs and nothing else. A picture-comparison program (SSCD, built on the ResNet-50 image model) reads every listing photo and turns it into a string of 512 numbers that stands for what the picture looks like, then scores any two photos for how close those strings are. Two ads in the same municipality are treated as the same home when at least three separate photos of one score 0.92 or higher against photos of the other — near-identical, on a scale whose top end means two pictures the program cannot tell apart — or are literally the same image file; when those matched photos cover at least 80% of the pictures in the shorter of the two ads and at least 25% of the pictures in the longer one; and when the advertised bedroom counts do not contradict each other. The price, the address and the description play no part in that decision, and that is deliberate: it is what keeps the price findings from being a by-product of the way we joined the ads.

What this data cannot tell you

Why these four municipalities. They were chosen for balance, not size: each of the five portals carried at least 295 rental listings in each of the four, which makes this the first sample where QuintoAndar, the smallest and most closed of the five, is present in enough volume to compare against the rest. Three metropolitan areas and three states are represented. São Paulo city, with more than half a million listings of its own, was deliberately left out of this round because it cannot be processed end to end on the hardware this ran on. Four municipalities are not a national sample, so the per-city figures are published alongside the combined figure instead of behind it.

How we checked the matching. Merge quality was audited three ways. Fifty groups of ads for one home — forty drawn at random and the ten largest — were checked photo by photo in ten independent review passes: 49 came back as one home, one as a mixed group, none unresolved. The mixed one turned out to be two different apartments in the same building, which is the hardest case there is for any method that goes by pictures. Group sizes showed no sign of over-grouping either: 5,393 homes with two ads, 1,568 with three, then a short tail down to a single largest group of 39 ads for one home. Wide price gaps inside one group are exactly what a bad merge would leave behind, and they stayed rare: on 0.57% of the homes with more than one ad, the most expensive ad was more than 1.5 times the cheapest.

Every bias we know about pushes the measured duplication down, so the shares above are floors, not estimates.

• The matching errs on the side of leaving ads apart. We audited 6,504 homes that had more than one ad. Cases where we wrongly treated two different homes as one came to 0.11%, and pairs we missed — two ads for one home that we left separate — are roughly twenty times more common than that. A dedicated check after this run found 34 genuine pairs that met every criterion and were still never joined, about 0.3% of the joins we actually made, plus 36 pairs that share only stock photos of a building's common areas and were correctly left apart.
• Ads with fewer than three usable photos cannot be matched at all. 201 ads in the sample were excluded on that basis.
• We only ever compare ads within the same municipality. The same home advertised under two different city names cannot be detected, by construction.
• Our collection runs did not catch everything. About 98.7% of the scheduled runs finished cleanly; on OLX, completeness can only be verified at state level, never per municipality. A listing missing from one portal's collection can only reduce measured overlap.
• Two flats in one building remain the hard case. One of the fifty groups we audited by hand was two distinct apartments in one building whose photographs and bedroom counts agreed. That is the one error that would inflate duplication, and at one in fifty audited groups it is small next to the misses in the other direction.
• Four municipalities are not Brazil. The per-city band ran from 46.71% to 62.21%, and São Paulo city, the largest rental market in the country, is not in this sample.
• These are asking prices. Everything here is what advertisers published on 27 July 2026, not what tenants signed. A gap between two ads is a gap between two asks.

We print the thresholds just above so that anyone who would have picked different ones can argue with ours, and so the next round can be compared against this one.

Who we are, and why we have this data

RemRent is being built as a search layer over six portals — the five in this article plus Viva Real, from the same Grupo OLX family — not another portal of its own. One place to search everything they all publish, with duplicates collapsed, so that a home advertised on three sites appears once and its three prices sit beside each other instead of three browser tabs apart. We have gathered {{corpus:total:prose}} listings from those sources so far — counted as posted, not after the repeats are merged — and that is what made this measurement possible at all. It will carry no homes of its own, run no credit check, and stand between no renter and no landlord.

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