Data sources

Fares: the Aviasales Data API, through the Travelpayouts affiliate programme: the cheapest prices Aviasales users found in the last few days. Not live quotes.
Airports, cities and airlines: Travelpayouts reference data, and OurAirports (public domain) for which airports have scheduled flights, the towns they serve and their states and provinces.
Cabin bag prices: the price ranges Ryanair and Wizz Air publish for a cabin bag added with the ticket (November 2026), and each airline's own published fare and baggage rules for which fares include a cabin bag (last checked 13 November 2026); every airline with its page: Europe, Southeast Asia.
How old a price can be: on 5 October 2026 we compared a sample of the prices we show in Europe with Ryanair's and Wizz Air's own published fares for the same flights, and in Southeast Asia, on 4 October, a sample with Kiwi.com's live prices for the same airline and flight, checked by hand. On 5 October, too, a sample of the long flights from home and the hops to them with Kiwi.com's live prices. That's where "may be higher now" starts: three days in Europe, four in Southeast Asia, three for a long flight or a hop.
Typical weather: weather-station normals (mostly 1991–2020, from national weather services and the WMO) as gathered in the climate tables of each city's English Wikipedia article (CC BY-SA 4.0).
The pictures on a trip's place cards: hills and mountains from the Copernicus GLO-90 terrain model (© DLR e.V. 2010–2014 and © Airbus Defence and Space GmbH 2014–2018, provided under COPERNICUS by the European Union and ESA; all rights reserved), sea and lakes from Natural Earth (public domain), and each town's size and high-rise buildings from Wikidata (CC0); the sky is the month's typical weather.
Ski places: the downhill runs near each place, from OpenSkiMap's ski areas, built from OpenStreetMap (© OpenStreetMap contributors, ODbL).
Northern lights places: each place's geomagnetic latitude from the dipole of the World Magnetic Model 2025 (NOAA NCEI, public domain), against how far south the auroral oval reaches in NOAA's Space Weather Prediction Center's guide; the hours of darkness worked out from the sun's height.
What to pack: worked out from the typical weather above and each place's daylight; the midday UV from how high the sun gets; the sea's temperature from NOAA's OISST 1991–2020 monthly averages (public domain); which places have a beach people swim at, checked by us place by place. Plug types from the IEC's World Plugs list; the money each country uses, by its ISO 4217 code.
Visa rules (the passport filter): the Passport Index dataset (MIT licence, from passportindex.org), updated 2026-02-17; Thailand's rules from 2026-09-15 are hand-checked against the official source (2026-10-02); Malaysia's rules from 2023-12-01 to 2026-12-31 are hand-checked against the official source (2026-11-11); Malaysia's rules are hand-checked against the official source (2026-10-07); Moldova's rules are hand-checked against the official source (2026-10-11); Armenia's rules are hand-checked against the official source (2026-10-04); Georgia's rules are hand-checked against the official source (2026-10-04); Türkiye's rules from 2026-01-02 are hand-checked against the official source (2026-10-04); Indonesia's rules are hand-checked against the official source (2026-10-06); Indonesia's rules from 2026-07-09 are hand-checked against the official source (2026-10-11); Vietnam's rules from 2026-07-15 are hand-checked against the official source (2026-10-11); Myanmar's rules from 2026-07-08 are hand-checked against the official source (2026-10-11); Myanmar's rules to 2027-10-20 are hand-checked against the official source (2026-11-11); Philippines's rules from 2026-01-16 to 2027-01-15 are hand-checked against the official source (2026-11-11); Hong Kong's rules from 2026-08-26 are hand-checked against the official source (2026-10-11); United Kingdom's rules from 2026-03-05 are hand-checked against the official source (2026-10-11); Ireland's rules from 2026-06-15 are hand-checked against the official source (2026-10-11); GI's rules from 2026-07-15 are hand-checked against the official source (2026-10-11); Montenegro's rules from 2026-11-01 are hand-checked against the official source (2026-10-11); Albania's rules to 2026-12-31 are hand-checked against the official source (2026-10-11); Albania's rules are hand-checked against the official source (2026-10-11); Singapore's rules are hand-checked against the official source (2026-11-11); Philippines's rules are hand-checked against the official source (2026-11-11); Laos's rules from 2026-01-15 are hand-checked against the official source (2026-11-11); Vietnam's rules from 2025-01-30 are hand-checked against the official source (2026-11-11); Timor-Leste's rules are hand-checked against the official source (2026-11-11); Serbia's rules are hand-checked against the official source (2026-11-11); South Korea's rules are hand-checked against the official source (2026-11-11); South Korea's rules to 2026-12-31 are hand-checked against the official source (2026-11-11); Hong Kong's rules are hand-checked against the official source (2026-11-11); India's rules are hand-checked against the official source (2026-11-11); FO's rules are hand-checked against the official source (2026-11-11); Türkiye's rules from 2026-01-02 are hand-checked against the official source (2026-11-10); Türkiye's rules are hand-checked against the official source (2026-11-10); Cambodia's rules are hand-checked against the official source (2026-11-10). Visas you already hold (a Schengen, UK or US visa): the Schengen area's rule from the European Commission (2026-10-05); United Kingdom's for a UK visa from its official source (2026-10-05); Serbia's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); Montenegro's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); North Macedonia's for a Schengen visa from its official source (2026-10-05); North Macedonia's for a UK visa, US visa from its official source (2026-10-05); Georgia's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); Moldova's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); Cyprus's for a Schengen visa from its official source (2026-10-05); Türkiye's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); Albania's for a Schengen visa, UK visa, US visa from its official source (2026-10-05); Bosnia and Herzegovina's for a Schengen visa, US visa from its official source (2026-10-05); Philippines's for a Schengen visa, UK visa, US visa from its official source (2026-10-05). Passport Index is a third-party compilation, not a government source, and a summary that can be out of date: check official sources before you travel.
Travel advisories: the Government of Canada's travel advice and advisories (Open Government Licence – Canada) and the US State Department's travel advisories, checked every night. We show their levels in short and link to each page; read the full advisory before you travel.
Seasons: typhoon, cyclone and monsoon-flood seasons from PAGASA (the Philippines), Vietnam's national forecasting centre, Myanmar's Department of Meteorology and Hydrology, MetMalaysia, the Thai Meteorological Department, BMKG (Indonesia) and the Mekong River Commission, in our words. Each trip page links the one it uses.
Disaster alerts: Orange and Red alerts from GDACS, the Global Disaster Alert and Coordination System of the United Nations and the European Commission, checked every night. Its alerts come partly from automatic models and can be wrong; local authorities' warnings come first.
Exchange rates: the euro foreign exchange reference rates of the European Central Bank, checked every night, for prices in currencies other than the euro.
Maps: coastlines and borders from Natural Earth (public domain).
Flags: country flags from Twemoji, © Twitter and contributors, CC BY 4.0.

We don't copy airline websites or Google Flights.