How We Rank eSIMs

eSIM Guide compares travel data plans from more than twenty eSIM providers. This page sets out where that data comes from, how it is processed, and how the ordering you see on a comparison page is decided. It is written so that you can check our figures rather than take them on trust.

Where our plan data comes from

Every plan on this site is pulled directly from the provider's own API. We do not copy listings from other comparison sites, and we do not retype prices by hand into a spreadsheet.

Each provider we list has its own integration: a client that talks to that provider's API, and a synchronisation service that maps their response onto our database. All of those services extend a single shared base class, so every provider passes through identical create, update and delete logic. We currently maintain integrations for more than twenty providers, covering plans across more than 230 countries and territories.

For each plan we store the provider's own price and billing currency, the validity period in days, the data allowance in megabytes (or a flag marking it unlimited), and the full list of countries the plan covers. Where a provider publishes them, we also store the fair usage policy, maximum and throttled speeds, any daily or weekly data cap, whether tethering is permitted, and whether identity verification is required at purchase.

How often the data is refreshed

A scheduled job runs continuously. On each run it selects the single provider whose data has gone longest without a refresh, and syncs it if it was last checked more than 24 hours ago, or has never been checked. In practice each provider's catalogue is re-read around once a day.

A sync is not a blind overwrite. We match the provider's current plans against what we already hold, using the provider's own plan identifier, and then:

• plans that are new in the provider's feed are added;
• plans we already hold are compared against a content fingerprint covering price, name, description, validity, data allowance, data caps, speeds, fair usage policy, tethering, verification requirements and country coverage. If the fingerprint is identical the record is left alone; if anything has moved, it is updated;
• plans that have disappeared from the provider's feed are removed from the site, together with their country and network associations.

Every sync writes back a status, a timestamp and, where something failed, the error itself — so a provider whose feed has broken is visible to us rather than quietly serving stale prices. When a sync produces changes, the cached pages for that provider and for every affected destination are rebuilt and resubmitted to search engines.

How we handle currencies

Providers bill in their own currency. We store every plan at the price and currency the provider actually charges, and convert only for display.

Exchange rates come from the Frankfurter API, which publishes European Central Bank reference rates. We fetch them against a US dollar base, store the snapshot in our own database, and refresh it once it is more than 24 hours old. Rates between two non-dollar currencies are derived from their respective dollar rates. The site currently supports display in US dollars, euros, pounds sterling and Singapore dollars.

Two caveats worth stating plainly. Converted prices are indicative: you will be charged in the provider's own currency, and your bank's rate and any foreign transaction fee will differ from a reference rate. And any converted price is only as current as our last rate snapshot and our last sync of that provider.

What price per GB means

Price per GB is the most useful way to compare plans offering different amounts of data, so we show it on most listings and let you sort by it.

The calculation is deliberately simple: the plan's displayed price divided by its data allowance in gigabytes, treating one gigabyte as 1,024 megabytes. If you have applied a discount code, the discounted price is used. Plans with no stated allowance — including unlimited plans — have no meaningful price per GB, so they are excluded from the figure and sorted last rather than being assigned an invented number.

To give that number context, we also calculate a median price per GB across the plans currently listed for the destination you are viewing, split into three duration bands: up to 7 days, 8 to 30 days, and more than 30 days. A plan more than 20% above the median for its band is highlighted in red, more than 20% below it in green, and anything in between in amber. That is a comparison against the plans on the page in front of you, not against the entire market.

How sorting and filtering work

Plan tables load ordered by price, cheapest first. You can re-sort by price, by data allowance, by validity or by price per GB, in either direction. Filters let you narrow by provider, by price range, by data range, by number of days, and to plans that permit tethering.

Sorting and filtering are applied to the plans themselves. There is no hidden weighting, no house preference and no provider variable in the ordering: pick "price per GB, lowest first" and you get exactly that, whoever sells it. Zero-price trial plans are hidden by default, because a free trial with a token allowance otherwise sits at the top of every price sort and tells you nothing useful.

What our provider scores mean

Where we show a provider a score out of ten, it is the average of four sub-scores, each also out of ten:

• Coverage — the number of countries that provider covers, expressed as a proportion of the widest-covering provider we list, scaled to ten.
• Pricing — the provider's average price per day across their catalogue, normalised against the cheapest and most expensive providers we list, then inverted so that cheaper scores higher.
• Satisfaction — the provider's Trustpilot rating, doubled onto a 0–10 scale. That is Trustpilot's number, not ours. We do not run our own review programme and we do not publish review counts we did not collect.
• Credibility — our own assessment of how transparent and dependable a provider is: whether their terms, fair usage policy and coverage claims are clear and hold up, and whether their API is honest about what they actually sell. There is no formula behind this one. It is set by hand, and we would rather say so than dress it up as a calculation.

The first three are calculated automatically from our own synced data and presented to us as suggestions, which we can adjust before publishing. The headline score is the mean of whichever sub-scores are set, and we only display a provider's score card once all four are present.

How our top picks are chosen

On destination pages we surface a small number of suggested plans — roughly one each for a week, a fortnight and a month of travel. These are selected by an automated score rather than by hand. It rewards a low price per gigabyte per day and a strong ratio of data to spend, penalises expensive unlimited plans (which routinely look better than they are), takes account of the provider's published features and their Trustpilot rating where it is 4.0 or above, and adds a bonus where an active discount code exists. Plans that fall below a minimum data allowance for their duration band are not eligible at all.

Rankings are not paid placements

We earn affiliate commission when you buy through our outbound links, which is set out in full in our affiliate disclosure. Commission does not appear anywhere in the calculations described above. No provider can pay to rank higher, to be sorted first, to be chosen as a top pick, or to be awarded a better score. There is no sponsored tier and we do not sell placement.

Two things are decided by us rather than by a formula, and we would rather name them than have you find them:

• Our provider directory pages, and the "other providers" sections, are listed in an order we set manually. That is an editorial running order for a directory, not a judgement of quality, and no money changes hands over it.
• Deals and discount codes are ordered by how prominent we judge them to be.

Where our written summaries come from

Some of the descriptive text on our destination and provider pages — country summaries, provider summaries and FAQ answers — is drafted by a large language model working from figures in our own database, then stored and versioned. The prices, allowances and provider details that appear in that text are drawn from the same synced data as the tables beneath it. We publish it under our own name and take responsibility for it. If any of it is wrong, that is on us.

How errors get corrected

Prices move. Providers change their catalogues without announcement, feeds break, and a plan can change between our last sync and your click. Always confirm the price, allowance and validity on the provider's own checkout page before you pay — that page, not ours, is the authoritative one.

If you find something wrong here — a stale price, a plan that no longer exists, a coverage claim that does not match what a provider actually sells — please tell us through our contact page. We will check it against the provider's live feed and correct it. Where the fault is in our own processing rather than the provider's data, we fix the code so that it does not recur.