Best eSIM Apps Compared (2026): Airalo, Holafly, Saily, Nomad, co:sim

Airalo, Holafly, Saily, Nomad and co:sim all sell the same basic thing: a QR code that turns into mobile data the moment you land. But they price, cap and refund that data very differently. Airalo wins on per-country price transparency, Holafly and Saily sell "unlimited"-labeled plans with a fair-use catch, Nomad undercuts on per-GB cost in Europe, and co:sim runs fixed-data-plus-FUP plans across 190+ destinations with a 30-day install-based refund window. This guide compares how each app prices, covers and refunds a plan, sourced from each provider's own current pages, so you can match the model to your actual trip instead of a marketing headline.

#What actually differs between eSIM apps?

Every major eSIM app resells the same handful of underlying mobile networks in most countries, so the real differences sit in three places: how data is metered (fixed GB vs. "unlimited" with a fair-use throttle), how the plan is priced (per-country marketplace vs. flat regional or global tiers), and what you can get back if a trip changes. A cheap headline price on a fixed-GB plan can still cost more per gigabyte than a pricier bundle once you factor in validity days and top-up cost.

co:sim's plan pages list the underlying network, the install deadline and the billing-start rule for each SKU before checkout, which is the kind of page-level detail worth checking on any app before you buy, not just co:sim's. A plan that "activates on first use" behaves very differently from one that starts counting down the moment you pay, and that single distinction affects both how long you can wait to install and whether the purchase is refundable at all.

#Airalo vs Holafly vs Saily vs Nomad vs co:sim: how the plans compare

#Does "unlimited" data actually mean uninterrupted speed?

No. Every major "unlimited" eSIM plan in this comparison, including Holafly's and Saily's unlimited and subscription tiers, is bound by the local network's fair-use policy rather than a hard data cap. Holafly's own Terms and Conditions state that an "unlimited" Trip Data Plan has no fixed allowance that automatically stops data use, but that coverage and speed "may be subject to a network service provider's fair use policy," which can reduce speed if usage is judged excessive or disruptive to other users (esim.holafly.com/terms-and-conditions). Holafly does not publish the exact daily threshold that triggers this; independent reviewers report throttling after roughly 2-5 GB of use in a single day, but that figure comes from third-party testing, not an official Holafly number, and it can vary by destination and operator.

co:sim doesn't sell unlimited plans at all: its data-only eSIMs are fixed-GB or daily-allowance, and each plan page states the data amount and validity rather than relying on a fair-use clause buried in the terms. A small number of destinations use a daily-throttle model instead, where speed drops once a daily data threshold is crossed rather than the connection cutting off entirely, and resets the next day. That's a genuinely different mechanic from an "unlimited-with-FUP" plan, and it's worth confirming which model a specific plan uses before a long trip, on any of these five apps.

#How do you install and activate any of these eSIMs?

Every app here uses the same underlying mechanic: buy inside the app or on the website, receive a QR code by email or in-app (co:sim sends it within seconds of checkout), install it under your phone's cellular settings before you fly, and activate it only once you land, since most plans' validity starts from first connection rather than from the moment you paid. On iPhone that's Settings → Cellular → Add eSIM; on Android it's typically Settings → Network & internet → SIMs → Add eSIM, though the exact menu path varies by manufacturer.

Installing over hotel Wi-Fi after arrival works too, but installing before departure avoids depending on airport Wi-Fi the moment you land. Every one of these five providers recommends exactly that in its own setup guide. If a plan bills from the moment of purchase rather than from first connection, install timing matters even more, since the validity clock is already running the day you pay.

#FAQ

#Is Airalo or Holafly cheaper for a short trip?

Closer than the marketing suggests, at least on the two examples checked directly. Airalo's Italy eSIM prices its 3-day "unlimited" plan at $11.00, scaling up to $64.00 for 30 days (airalo.com/italy-esim); Holafly's Europe eSIM prices 3 days of "unlimited" data at $11.90, up to $73.90 for 30 days (esim.holafly.com/esim-europe). Both label the plan "unlimited" and both are bound by a fair-use policy, so on that specific comparison, Airalo is marginally cheaper across most validity lengths. Prices vary by destination, currency and promotion though, so treat any single country pair as an example, not a universal rule, and check each provider's own current page before comparing your actual route. Airalo also still sells separate fixed-GB bundles for some regions, which can undercut either "unlimited" option if your real usage is genuinely small.

#Does Saily really refund unused data?

Saily's published policy allows a full refund within 30 days of purchase if the eSIM was never installed or the data plan never activated. Once activated, Saily treats the plan as used and won't guarantee a refund, but it will still consider one if less than 1% of the data allowance has been used, or if verified connection problems on Saily's own side prevented normal use. A separate subscription-based tier only qualifies for a refund if usage stays under 5% of the period's allowance and the request comes within 14 days of the charge. All of this comes from Saily's own Terms of Service, as summarized on its Help Center, and none of it applies once a plan has simply expired unused — expired, unused data is not refundable either way.

#Is co:sim's data actually unlimited?

No. co:sim sells fixed-data and daily-allowance data-only eSIM plans rather than "unlimited" ones, and each plan page states its data amount, validity and install deadline directly rather than relying on a fair-use policy buried in the fine print. A small number of destinations use a daily-throttle FUP model instead of a fixed total: once a daily data threshold is crossed, speed drops rather than the connection cutting off entirely, and it resets automatically the next day, so a heavy-use day slows the connection rather than ending it. That's a genuinely different mechanic from Holafly or Saily's "unlimited-with-fair-use" plans, where the headline word is "unlimited" and the throttle terms sit in the small print instead. Either way, checking which model a specific plan actually uses matters more, before a long trip, than the word printed on the storefront.

#Which app has the widest coverage for a Europe trip?

Coverage depends on the specific regional bundle bought, not just the brand name attached to it. For Europe specifically: Airalo's Europe plan lists 41 countries, co:sim's Europe (42 areas) plan lists 41 destinations, Nomad's Europe plan lists 35 countries, and Holafly's Europe plan lists 33 — figures pulled from each provider's own current page, since regional country counts shift over time as suppliers add or drop individual networks. For a single-country trip rather than a multi-country one, check that provider's specific country page rather than assuming a big global country-count headline applies evenly everywhere, because which local network you actually connect to, and how good that network's coverage is, varies by country even within the same brand's regional bundle. A wide country count on the box is a starting point for screening options, not a guarantee that every one of those countries gets equally strong 4G or 5G.

#Do any of these eSIMs include a phone number?

No. All five are data-only eSIMs. None of Airalo, Holafly, Saily, Nomad or co:sim's standard travel plans include a phone number, voice minutes or SMS; you get mobile data only, and calls or texts go through an internet-calling app such as WhatsApp or FaceTime. If you specifically need a local number for SMS verification codes or a callback number, none of these five solve that on their own — that requires a separate service or a physical SIM with voice support, alongside whichever data eSIM you install.

Every app in this comparison solves the same basic problem, data on arrival without a roaming fee, and the right pick depends on how much you'll realistically use rather than the biggest number on the landing page. If your usage is light and predictable, a fixed-GB plan from Airalo, Nomad or co:sim tends to be the better value; if you'll stream or hotspot heavily and want to stop counting gigabytes entirely, an unlimited-labeled plan from Holafly or Saily is the more forgiving choice, provided you've checked its fair-use terms first.