Sailyは、対応端末であればベトナム到着前に設定できる旅行用eSIMです。ただし、「おすすめか」はブランド名だけで決まりません。端末がeSIM対応・SIMロック解除済みか、現地番号が必要か、旅程が都市中心か、必要なデータ量はどれくらいかを先に確認します。
この記事では広告リンクを含みますが、購入を前提にせず、Sailyが向く条件と現地SIM・Wi-Fiが向く条件を分けて説明します。プラン、価格、通話・SMSの提供状況は変わるため、購入画面の当日表示を優先してください。
先に結論：購入前の5項目
- 端末がeSIM対応で、通信事業者のロックがない
- データ専用で足りるか、ベトナム電話番号が必要か
- 利用日数、容量、速度制限後の条件
- テザリングする端末数と想定データ量
- 開通に備え、アプリ・QR・サポート情報を日本で準備できるか
What is Saily? An overseas eSIM from the company behind NordVPN
Sailyは、VPNで有名なNordVPNを手がけるNord Securityが提供する海外旅行用のeSIMです。200以上の渡航先向けプランを案内しており、専用アプリから国とデータ量を選んで購入すると、eSIMを設定できます。物理SIMの差し替えは不要ですが、端末の対応状況とSIMロック解除を事前に確認する必要があります。セキュリティを本業とする会社らしく、通信の安全性に配慮されているのも特徴です。
Does it actually work in Vietnam?
Sailyはベトナムを対応エリアに含んでおり、現地の大手回線を通じて通信します。ホーチミン・ハノイ・ダナンといった都市部や主要観光地で利用できる設計ですが、実際の速度と接続先は時間・場所・提携回線・混雑で変わります。地図や配車は比較的少ない通信量で使えますが、ビデオ通話は速度と容量を多く消費します。一方で、山間部や離島など電波の弱いエリアでは現地キャリアと同じく速度が落ちることがあります。とはいえ、旅行者が訪れる範囲の大半はカバーされているので、「都市と主要スポット中心」の旅ならまず困りません。
From purchase to activation to checking your remaining balance, it's all in one app. You're online the moment you land in Vietnam. You can pick just the amount you need for a short trip, and the price is reasonable too.
Saily's advantages
Its biggest strength is the ease of doing everything in the app. Purchase, activation, checking your balance, and topping up all happen in a single app, and you can see at a glance how much you've used. A big plus is that if you set it up while still in Japan, you're online the moment you land in Vietnam. Since you can run two lines while keeping your Japanese SIM, you can also keep using your Japanese phone number and LINE as is. And if you choose an Asia-roaming plan, it works as-is in Thailand and Cambodia too, sparing you the hassle of buying a new one in each country.
Saily plans available for Vietnam
Saily's plans for Vietnam come in two types: a "data plan" chosen by data volume, and a "calls & text plan" for local calls and SMS.
The data planlets you choose by length of stay and data amount, from 1GB (for short trips) up through 3GB, 5GB, 10GB, and 20GB. A small allowance is enough if you mainly use maps and social media; a larger one is reassuring if you'll tether or watch video.
The calls & text plancovers calls and SMS within Vietnam, available in tiers from 5 minutes/5 SMS up to 50 minutes/50 SMS. Both outgoing and incoming use the plan's minutes. In other words, Saily isn't strictly "data only" — you can add calls and SMS as needed. If data alone is enough, go with just a data plan; if you also want to make calls locally, add calls & text.
*Plan lineup and pricing change. Check the latest volumes and prices in the official Saily app.
Points to watch out for
Saily centers on data, but in Vietnam you can also add a calls and SMS plan, which covers local calls and SMS (within the plan's minutes and message count). However, if you need to receive calls on a Vietnamese number or get SMS verification sent to a Japanese number, a local SIM or your Japanese SIM is the better fit. You'll also need an eSIM-compatible phone, so before you leave, check that you can add an eSIM under "Settings → Cellular." "Unlimited" plans may throttle speeds past a certain amount, so if you watch a lot of video, it's worth checking how much high-speed data is included.
Who it's good for / who it's not for
Saily is a good fit forshort- to mid-length travelers who mainly stick to cities、people who want to handle setup and balance management smartly through an app、people who'll also tour other parts of Asia beyond Vietnam. Conversely, forpeople who must receive calls or verification on a local numberandpeople using a device that doesn't support eSIM、people on a long stay who put down deep local roots, a local SIM or a rental WiFi unit suits better. Choose based on your own travel style.
Setup and use in 3 steps
(1) Buy a plan for Vietnam (or Asia roaming) in the app. (2) Register the QR/eSIM shown, while still in Japan, under "Settings → Cellular → Add eSIM." (3) After arriving in Vietnam, turn on the eSIM you added and enable "Data Roaming." That gets you online. The trick to avoiding mishaps is finishing the setup in Japan where there's Wi-Fi.
For how to choose between Vietnam's SIM, eSIM, and WiFi overall, our definitive guide compares them in detail 👉 Which SIM is right for Vietnam? A thorough comparison of local SIM, eSIM, and WiFi
From purchase to activation to checking your remaining balance, it's all in one app. You're online the moment you land in Vietnam. You can pick just the amount you need for a short trip, and the price is reasonable too.
まとめ：便利さより、番号・容量・端末条件で判断
Sailyは、都市中心の短期旅行で、データ通信を日本出発前に用意したい人には候補になります。一方、現地電話番号での着信・認証が必要な人、eSIM非対応端末、地方で通信会社を選びたい人は現地SIMも比較してください。
購入後は日本のWi-Fi環境でeSIMをインストールし、主回線のデータローミングを切る設定を確認します。現地でつながらない場合に備え、ホテル住所、予約番号、サポート手順をオフライン保存しておくと安心です。
