Understanding eSIMs — and How to Choose Between Two Top Players: Saily vs Airalo

When travelling (or even when staying put but wanting more flexibility in connectivity), eSIMs offer a compelling alternative to physical SIM cards. In this post I’ll cover:

• What an eSIM is and why it matters

• Key pros & cons of eSIMs

• How Saily and Airalo compare — where they shine, where they differ

• Which one might suit you better

What is an eSIM?

An eSIM (“embedded SIM”) essentially replaces the need for a physical SIM card by embedding the SIM profile directly in your device’s hardware. You can download and activate it via app, switch carriers, or add a second line without inserting a new card.

Why it matters when travelling

• No need to buy a local physical SIM on arrival, queue up, or mess with the tray. Saily+1

• Often cheaper than international roaming or airport SIMs.

• You can keep your regular number active (for e.g., WhatsApp or calls) while using a data-only eSIM for internet.

• Greater convenience and flexibility: install ahead of travel, switch between plans, multiple profiles on device.

Some caveats

• Your device must support eSIM (most modern phones do, but always check). NordVPN

• Some eSIM plans are data-only (no local number for calls/SMS) — depending on provider.

• Coverage and network performance still depend on local partner carriers; cheaper “global” eSIMs might have compromises in speed/latency. For example, some travellers reported mixed experience with Airalo.

• Activation logistics: in some countries you may need to install prior to arrival, or local restrictions may apply. For instance, some eSIM provider apps/websites were blocked in Turkey if not activated ahead of time.

Introducing the Two Providers

Airalo

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• Founded in 2019; provides eSIM services in 200+ countries/regions worldwide. Airalo+1

• Over 20 million users as of 2025.

• Offers local, regional, and “global” eSIM plans.

• Compatible with both iOS and Android, multi-language support.

• Pricing starts low (e.g., plans from ~$4.50 for 1 GB in some markets) and the setup is quite streamlined.

Strengths

• Very broad coverage: useful if you travel to many countries or less-common destinations.

• Mature brand with large user base.

• Good reviews for ease of setup: one Reddit user said:

  “Very easy to use and means you’re ready to hit the ground running when arriving in country.”

Potential Weaknesses

• Because of the scale, there are reports of mixed experiences: for example, in one review:

  “I used it in two different countries and had vastly different experiences.”

• Some of the very cheapest plans might have trade-offs in speed/priority compared to local full-carrier plans.

• Call/SMS functionality may be limited depending on plan (many eSIMs remain data-only). For example, in the list of best eSIMs for Europe in 2025, Airalo was flagged as data-only. TechRadar

Saily

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• Launched by the company behind NordVPN (Nord Security) to serve travellers with data-only eSIM plans.

• Coverage in 150+ (or more than 150) countries, with plans beginning from very low prices (e.g., from ~$2.49 depending on country).

• Unique selling point: built-in security features like ad-blocking, web protection, virtual location (VPN-type features) integrated into the eSIM app.

Strength

• Affordability: many reviewers note that Saily tends to be slightly cheaper. For example:

  “Saily is the most consistently affordable eSIM option …”

• Security-focused: if you care about safe public WiFi, encrypted traffic, ad blocking, this gives Saily an edge.

• Data-only means you can keep using your home number for calls/SMS and avoid roaming charges—especially useful if you primarily need internet access abroad.

Potential Weaknesses

• Data-only: no built-in phone number for local calls/SMS (depending on provider) — this may or may not matter depending on your use. For travellers largely using VoIP, this is fine. Note: TechRadar’s guide said Saily’s plans were data-only.

• Coverage/performance may still depend on local carriers and in some destinations may be less seamless than local SIM or premium eSIM plans.

• Because it’s newer compared to some big players, fewer user stories for every single country.

Head-to-Head: Saily vs Airalo

Which Should You Choose?

Here are some scenarios to guide your choice:

• If you travel to many different countries, including lesser-visited ones, and want the broadest coverage: go with Airalo.

• If you primarily need mobile data (for maps, WhatsApp, streaming) and don’t care about getting a local number for calls/SMS, then Saily is very appealing — especially thanks to its price and security features.

• If you value extra security, e.g., you often use public WiFi, want ad-blocking, web protection, then Saily has a distinct advantage.

• If you might need calls & SMS using the eSIM (for local contacts, local number) — check carefully which plan supports that. Airalo may have more options.

• Device compatibility: Make sure your phone is unlocked, supports eSIM and that you install/activate before your trip (or at least know how to).

• Activation logistics: in some countries there may be issues if you don’t activate ahead of arrival (see notes about Turkey blocking some provider apps). TechRadar

Final Thoughts

eSIM technology is a game-changer for travellers — no more swapping SIM cards, no more overpriced roaming. Both Airalo and Saily are very credible choices, each with slightly different emphasis:

• Airalo = wide-reach, flexible plan types, established player.

• Saily = ultra-affordable (in many cases), security-first, data-only focus.

If I were to pick a recommendation: for general use, I’d lean Saily unless you specifically need a local number and are going off-grid into very niche destinations — then Airalo would win.