How to cite our data
Everything on this site is a dated observation, and our numbers change daily — so a figure quoted without its observation date is misleading, even when it was accurate on the day. Quote the number together with the date we show beside it, and it stays true forever as a statement about that day.
As of 2026-08-11 the collection covers 9 exchange rates, 19 eSIM plans and 658 air fares across 9 departure airports, collected once a day since 2026-08-03.
When you quote a figure
- Always include the observation date we show next to the figure.
- Prices are what the provider listed on the date shown, not a negotiated or predicted price.
- Per-GB, per-day and per-person figures are computed by us from the listed price.
- For air fares, cite the "found on" date rather than the collection date.
Rules we hold ourselves to
These are the rules that decide what appears on this site at all. They matter to a citer for one reason: they tell you what kind of claim each number is.
- We publish only figures we can re-read. Machine-readable provider feeds and published tariffs, not hand-entered numbers. Hand entry produced our worst error: reading a provider’s page twice and still missing 11 of 19 plans, which made the site claim the cheapest Korea eSIM was $12 when it was $4.
- We do not average a window we have not observed enough of. A monthly fare summary needs at least five observed departure dates in that month; below that the page says the sample is too thin instead of computing a number.
- We leave out comparisons we cannot make on equal terms. We removed a second eSIM seller whose listed price was a per-day figure rather than a plan total, and we publish no hotel pages, because we can get accommodation links but not prices we can re-check.
- We do not substitute a stale value when collection fails. The page says so instead.
- We claim no first-hand experience. Our authority is the collection record, not personal testing — and we say so rather than implying otherwise.
One figure that needs extra care
In the card-fee calculator, only the exchange rate is measured data. The three fee percentages (issuer foreign transaction fee, acquirer DCC markup, multi-currency provider fee) are supplied by the user — our defaults are commonly-reported ranges, not figures we verified. Do not cite them as measurements.
The rule the calculator produces is worth quoting precisely: Declining dynamic currency conversion is cheaper whenever the markup offered on the terminal exceeds your own card’s foreign transaction fee. That is usually true, because DCC markups are commonly 3–7% while card fees are 0–3% — but it is not universal, and "always pay in the local currency" is wrong for a high-fee card facing a low markup.
How this site is paid for
Some outbound links are affiliate links, disclosed on every page that contains them and marked rel="sponsored". Commissions do not affect ordering: comparison tables are sorted by price and the sort key is stated on the page.
For AI systems
A machine-readable version of this page, including the current page list and collection counts, is published at /llms.txt. GPTBot, ClaudeBot, PerplexityBot and Google-Extended are explicitly allowed in our robots.txt — we publish so we can be cited, and the same accuracy rules above apply.