How we rank
How our rankings work, and why you can trust them — laid out in full.
1. What we believe
- There is only one definition of "cheap": how much your whole trip costs.
- $4 for 1GB sounds cheap — until you realize it lasts 3 days ($1.33/day). $9 for 10GB lasting 30 days is $0.30/day. Headline prices mislead; totals can mislead too, when you buy data you'll never use.
- We optimize for one thing: the lowest total cost that covers your entire trip.
2. The ranking algorithm, in plain English
- You tell us: destination, trip length, and daily usage (Light <1GB, Medium 1–3GB, Heavy >3GB).
- We estimate total data: days × daily usage. 7 days at Medium (~2GB/day) ≈ 14GB.
- We find candidates: every plan whose validity covers your whole trip. Stacking up to 3 of the same plan is allowed — because two small plans are sometimes cheaper than one big one.
- We sort by total trip cost, low to high. No other weights. No sponsored slots. No human overrides.
Worked example (illustrative numbers): Japan, 7 days, Medium usage → ~14GB needed.
Plan A: 10GB / 30 days / $6 × 2 = 20GB, valid 30 days ≥ 7 days → $12 total.
Plan B: 20GB / 15 days / $16 × 1 = 20GB, valid 15 days ≥ 7 days → $16 total.
Plan A costs less, so Plan A ranks first. That's it.
3. Why our "no paid ranking" promise is verifiable
- Our ranking code is public — open-sourced on GitHub (esimtrue-calculator, MIT license). Anyone can recompute any ranking with the same data and verify it's honest.
- If we ever took money to boost a provider, the code would lie — and code can't hide. That's verifiable neutrality, not a slogan.
- Compare: some comparison sites claim "fully independent & unbiased" on their homepage while their terms of service reserve the right to sell "sponsored placements". We don't play that game: rankings are price-only, always.
4. Data sources & freshness
- Public prices from provider websites (Airalo, Holafly, Saily, Nomad, Ubigi, and others).
- Public listings from third-party aggregators are used only for discovery; prices are verified against official provider channels.
- Freshness: official price data syncs daily; other channels are spot-checked regularly; every page shows its data date.
5. Limitations, stated upfront
- Promo prices change: for plans labeled as promotional, the merchant's live page is authoritative.
- "Unlimited" rarely means unlimited high-speed: most unlimited plans have a fair-use policy — speeds drop after the high-speed allowance. Check the fine print before buying.
- Our three usage tiers are estimates: heavy users (hotspot all day, streaming video) should estimate one tier up.
- All prices in USD; currency conversions are indicative.
This methodology is our own straitjacket: public algorithm, price-only rankings, limitations stated first. If you ever catch a ranking that contradicts it, tell us at
[email protected] — we'll fix it.