Coverage count gives you a fast read
Start with how many countries a plan covers, because that number tells you at a glance whether an eSIM suits a trip across borders or a stay inside one market. A1 Telekom Austria covers 137 countries and is sold as global coverage, which suits a traveler moving between continents. AeroSims is close behind with 175 to 195 countries, and its reach is listed as regional and global, so some of its plans are aimed at regional trips rather than the whole map.
Other brands sit much further down the list. 1&1 (1und1) covers 33 countries and is sold as regional, A1 Macedonia covers 33 countries, and A1 Serbia covers 10 countries. 2degrees is the narrowest option here, with a single market, 1, and A1 Hrvatska matches that shape with 1 country. Wide coverage helps a long itinerary, while a single-market plan keeps the decision simple, and the best travel eSIMs ranking shows the full spread side by side.
Region labels tell you how the coverage is sold
A country count alone does not tell you how a plan is meant to be used, so read the region label beside it. 3 Denmark pairs 100 countries with global scope, and A1 Bulgaria is listed with from 100 countries under global coverage.
Regional labels point to a tighter set of destinations. 4ka covers 18 countries and is sold as regional, which fits a trip that stays in and around a home market. A1 Slovenija covers 5 countries, a similar reach for a traveler who does not plan to cross many borders. Local labels are the most specific of all, since 2degrees and A1 Hrvatska are both listed as local and local. If your route never leaves that market, a local plan is the straightforward choice, and the 2degrees review shows how one is described in practice.
The host network behind the coverage
Coverage figures are drawn from partner networks, so it helps to know which ones sit behind them. 1&1 (1und1) is an unusual case, since its network is its own and is listed as 1&1 Mobilfunknetz (Open RAN) and Telefonica Germany (national roaming), covering an Open RAN build plus a national roaming arrangement with Telefonica Germany in Germany. 2degrees lists 2degrees and One NZ, so its service runs on its own network and on One NZ.
The A1 group shows how long a partner list can get. A1 Telekom Austria publishes USA: AT&T, T Mobile, Verizon, UK: Vodafone, 3, T Mobile, Virgin Media O2 and Japan: DoCoMo, Softbank, KDDI, grouped by country, from AT&T, T-Mobile and Verizon in the USA to China Mobile, China Unicom and China Telecom in China. A1 Slovenia lists Vodafone, O2 and Orange, A1 Serbia lists A1, Yettel and mts, and A1 Macedonia lists A1 Serbia, MTS and Telenor Serbia, which names operators such as MTS, Telenor Serbia, Vodafone, Telekom Montenegro, M-Tel and IPKO. AeroSims runs on AT&T, NTT Docomo and SoftBank, a mix of AT&T, NTT Docomo, SoftBank, au by KDDI, Vodafone, O2 and Vodafone Türkiye. A long partner list is a good sign for cross-border travel, because it means the plan borrows established networks rather than relying on one operator.
5G, and who offers it
Network generation is the next box to tick, though it carries less weight abroad than it does at home, because the network your phone lands on decides what you can reach. 1&1 (1und1), 2degrees, 3 Denmark, 4ka, A1 Bulgaria, A1 Hrvatska, A1 Macedonia, A1 Serbia, A1 Slovenija, A1 Telekom Austria and AeroSims all list 5G as available.
Treat 5G as a bonus rather than a requirement on a trip abroad. A brand that offers 5G at home may land you on a partner network with a different generation, and a plan you will use for maps, messaging and payments does not need the fastest option available. Check the generation where you will actually be, and use the reviews to see how travelers describe it.
Tie coverage to price and data allowance
Coverage tells you where a plan can work. Price and data allowance decide whether it is worth buying, and both sit next to each plan in the Travel SIMs and eSIMs comparison. Read a wide-footprint plan as a bundle: when several listed countries are on your route, the cost spread across usable days can beat a cheaper local plan, while a short trip to one country is usually better served by a local or single-market eSIM.
Allowance is what caps your usage, so match it to how you travel. Video streaming, frequent mapping and photo uploads consume data quickly, and a plan with a small allowance becomes the more expensive choice over a long trip. Where a plan is sold with a cover limit instead, treat that limit as the ceiling for the whole journey rather than something you can top up on the road. Compare the listed price with the allowance printed next to it, and never with the country count alone, since the cheapest headline price can carry the smallest allowance.
Match the plan to your route
A single-city break is well served by a local plan. 2degrees covers a single market, 1, and A1 Hrvatska covers 1 country, so neither asks you to think about borders at all.
A road trip through the western Balkans is a regional question. A1 Macedonia covers 33 countries as regional coverage, and A1 Serbia covers 10 countries as regional. The A1 Macedonia review sets out how that regional set is described, which helps you judge whether your own route sits inside it.
A long trip across Europe and beyond is a global question. 3 Denmark lists 100 countries as global, and A1 Bulgaria lists from 100 countries as global, so you would not need to check which country you are entering. The 3 Denmark and A1 Bulgaria reviews are worth reading before you commit. Tighter regional loops suit 1&1 (1und1) and 4ka instead, so start from your itinerary, then check the country count, the region label and the host network against it.