— Methodology
Methodology
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Faro is an automated aggregator of abnormally low air fares. This page says where the prices come from, what makes one an error fare, how large the sample behind each figure is, and what the method cannot see. Every number on this page is counted from the database at the moment you load it.
1. Data source
Prices come from the Travelpayouts Data API. Faro negotiates no fares and gets no advance notice of a promotion.
Faro watches 74 departure airports across 9 markets, and asks for departure dates in the 6 whole months after the current one — one request per month, per airport, each time that market comes up in the rotation.
The endpoint used returns the cheapest fares real travellers found in the previous 48 hours. That is the most important thing to know about everything below: Faro never sees a route's whole fare table, only the cheapest fares somebody actually searched for.
2. What counts as an error fare
Each fare is compared with the median of the fares active right now to the same destination airport, from any origin, inside the same market. The market boundary is deliberate: a cheap fare out of a low-cost hub has to be judged against fares in its own country, or ordinary low-cost prices get flagged in bulk.
With fewer than 5 active fares to that destination, Faro falls back to that one route's own price history over the last 30 days. With fewer than 2 observations either way, the fare gets no verdict at all: no reference price, no discount, and it is never published as an error fare.
A fare qualifies when it sits at least 40% below the median, and at least 50% below it once the sample reaches 5 fares. A bigger sample makes the median more trustworthy, so the bar goes up rather than down.
3. The sample behind the median
Route history is one price point per route per day, and that point is the average of the day's active fares on the route rather than a single fare. Faro holds 6 639 132 price points across 41 713 routes.
The oldest point held is from and the newest from . A 30-day median therefore rests on at most 30 daily price points for a route, however far back the whole history goes.
4. What is re-checked, and what is not
Every active fare is scored again against the current median each time its market is fetched. There is no second, separate request to confirm a single fare — the re-score uses the batch that was just fetched, and that is the whole of the verification.
The time Faro first saw a fare is stored and shown on that fare's page. It records a first sighting. It is not a promise the fare is still on sale.
5. Publication
No fare is picked, promoted or ordered by hand. The order is the gap from the median, largest first, or whatever the reader has filtered by.
No airline pays Faro to feature a fare. The income is affiliate commission from Travelpayouts (Aviasales) when a reader books after following a link. It is the same commission whichever fare they follow, so it cannot move the selection or the order.
6. Expiry and archiving
A fare leaves the list for one of three reasons: the flight has departed, the validity window the provider gave has passed, or no fetch has seen the fare for seven days. Faro does not query fares one at a time to confirm they are gone.
Expired fares stay in the public archive, marked as not bookable, with the date they left and the validity window the provider gave. This market's archive holds 45 987 fares, the oldest leaving the list on .
Of those, 43 908 carry a validity window from the provider. The median window is 216 hours, and 0% of them were shorter than a day. This is a window the provider declared, not a lifetime Faro timed: Faro cannot see the moment an airline corrects a price.
7. What this method cannot do
Faro shows the fare the provider returned. The price at checkout can differ — baggage, taxes, seat choice, live availability — so check the final fare on the airline or booking site before paying.
A fare can be gone between appearing here and your booking attempt. That is what an error fare is.
Four things this method cannot see, stated plainly: a route's full fare table, because the feed returns only the cheapest fares travellers searched for; a fare that is equally cheap from every origin, because the comparison is between origins; whether a fare was an airline mistake or a deliberate sale, because Faro measures the gap and not the intent; and any fare on a route with fewer than 2 observations.
8. Transparency
The method runs automatically and identically on every market, and no fare is hand-picked. The archive and the price index behind these figures are public, and the index can be downloaded as JSON or CSV.