The standard eSIM installation process requires an internet connection to download the carrier profile from the provider's server. But Wi-Fi is not the only option. If you have any existing cellular data connection, that works just as well.
This guide covers every method for installing and using an eSIM when Wi-Fi is unavailable, including the manual activation code approach that works with minimal bandwidth.
Step-by-step instructions
- 1
Use your existing cellular data to download the eSIM
If you have an active physical SIM or another eSIM with data, you can use that connection to download the new eSIM profile. The download is only 50KB to 200KB, which completes in seconds even on a slow 3G connection. Simply scan the QR code as normal through your phone's eSIM settings.
The phone uses whatever active internet connection is available, whether that is Wi-Fi or cellular data.
Tip: If you are at an airport with a physical SIM that has roaming data, use that connection to install your travel eSIM before switching data lines.
- 2
Use a mobile hotspot from another device
If your phone has no active data but someone nearby has a phone with internet, ask them to enable Personal Hotspot (iPhone) or Mobile Hotspot (Android). Connect your phone to their hotspot via Wi-Fi, then scan the eSIM QR code. The 50KB to 200KB download takes under 30 seconds on any hotspot connection.
This is the most common solution at airports when your own SIM has no roaming data.
Tip: Airport lounges, coffee shops, and even airline gate agents can sometimes share a Wi-Fi connection if you explain you need 30 seconds to download an eSIM profile.
- 3
Enter the activation code manually
If you have no internet at all, some providers provide an SM-DP+ address and activation code via email or in their app (which you can cache before losing connectivity). On iPhone, go to Settings > Cellular > Add eSIM > Use QR Code > Enter Details Manually. Type the SM-DP+ address and activation code.
On Android, select 'Enter code instead' on the eSIM setup screen. Note that this method still requires a brief internet connection to complete the server handshake after entering the code. It does not work in true offline mode.
Tip: Save your provider's activation code in your phone's Notes app or take a screenshot before your trip. The code works even if you cannot scan the QR image.
- 4
Confirm the eSIM works over cellular data with Wi-Fi off
Once the profile is installed, turn off Wi-Fi entirely and verify the connection holds on cellular alone. On iPhone, check Settings > Cellular for a carrier name and signal bars next to the new line. On Android, check Settings > Network & internet > SIMs for the same.
Open any app or webpage to confirm data loads. If the new eSIM is installed but not connecting, make sure it is set as the active data line, since a phone with two profiles only routes data through whichever one is selected.
Tip: Give the network up to two minutes to register your device after installation before assuming the connection failed.
Frequently asked questions
Can I install an eSIM completely offline with zero internet?
No. The eSIM profile must be downloaded from the provider's SM-DP+ server, which requires an internet connection. The download is small (50KB to 200KB), so even a very slow connection works. You can use cellular data, Wi-Fi, or a hotspot, but you need some form of internet access for the initial installation.
How much data does eSIM installation use?
The eSIM profile download uses 50KB to 200KB of data. This is less than loading a single webpage. If you have a physical SIM with even 1MB of roaming data remaining, that is enough to download multiple eSIM profiles.
Can I use a previously installed eSIM without Wi-Fi?
Yes. Once an eSIM profile is installed on your device, it works independently of Wi-Fi. The eSIM connects to cellular networks directly, which is the entire point. Wi-Fi is only needed for the initial profile download.
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