Wi-Fi QR Codes Explained

If you've ever been the host who reads out a long password, or the guest who squints at a garbled network name while typing it twice, a Wi-Fi QR code is the fix. It turns your network details into a code that connects a phone in a single scan — no typing at all. This guide explains how the format works, how to create one with SajiloQR, and the important security caveats most tutorials skip.

What a Wi-Fi QR code actually is

A Wi-Fi QR code is not a special kind of code. It's a normal QR code whose text happens to be a short, standardised string that phones recognise. The format looks like this:

WIFI:S:MyNetwork;T:WPA;P:secret123;;

The pieces are simple:

• WIFI: — the prefix that tells the phone "this is a network".
• S:MyNetwork — the SSID (network name).
• T:WPA — the security type: WPA/WPA2, WEP, or empty for an open network.
• P:secret123 — the password.
• Two semicolons ;; close the string.

When the phone decodes this, it doesn't open a website — it shows a prompt to join MyNetwork. One tap and you're connected.

How to create one with SajiloQR

You never need to type the format above. In the generator:

• Set the Type dropdown to Wi-Fi Network.
• Enter the network name (SSID) — exactly as it appears, including capitals and spaces.
• Enter the password.
• Download the PNG and test it by scanning from a phone that isn't already connected.

SajiloQR builds the WIFI: string behind the scenes, so there's no room for a syntax typo.

Why it's so handy

• Home guest networks — print it, stick it on the fridge, and guests join without asking.
• Cafes, salons, and shops — a small card on the counter replaces "the password is..." said fifty times a day.
• Airbnb rentals and short-stay properties — leave a printed code on the welcome card.
• Offices — boardroom visitors can connect themselves instead of hunting down IT.

The security caveat you must understand

Here's the part worth slowing down for. The password is stored inside the code as plain readable text. Anyone who scans the code, photographs it, or gets their hands on the file can read the password directly. In other words:

• Treat a Wi-Fi QR code the way you'd treat a Post-it with the password written on it.
• Don't post it publicly on social media, and don't email it around.
• For a public space, share a code for a dedicated guest network, not your main network. On most routers you can create a separate SSID with its own password — and even better, one that's isolated from your main devices.
• If your password leaks, change it — and generate a new code, since the old code still carries the old password.

Open (no-password) networks

You can also make a code for a network with no password. The T: field is simply left empty. This is convenient, but remember: an open network sends traffic unencrypted, so anyone nearby can capture what visitors do. Use an open network QR code only in low-risk settings, and never for anything involving logins or payments.

WPA3 and modern routers

Newer routers use WPA2 or WPA3, and the WIFI: format was designed when WPA was the standard. In practice, phones handle this fine: they read the name and password and connect using the security type the network actually broadcasts. You don't need to specify WPA3 in the code — the phone figures it out. If you have an unusual setup (for example, WPA2-Enterprise with a username), the basic QR format can't express it, and you'd need your router's own QR export feature if it has one.

Frequently asked questions

Does the code expire?

No. Like every static QR code, it encodes the data permanently. It will connect devices years from now — as long as the network name and password still match. Change either one and you need a fresh code.

Will it work with any phone?

Nearly all modern iPhones and Android phones recognise the WIFI: format natively in the camera app. It's an open standard, not an Apple or Google proprietary feature.

Can I see the Wi-Fi password from the code?

Yes — scan it with a plain QR reader and the decoded text will show WIFI:S:...;P:...;;. That's exactly why you should guard the code itself.

Ready to try it? Open the generator, pick Wi-Fi Network, and create a code for your home network. Then test it from a phone on airplane mode with Wi-Fi off — it should reconnect you in one tap.