How do phones join WiFi from a QR code?

Most iOS and Android cameras recognize the `WIFI:T:…;S:…;P:…;;` payload and offer to join that network. The guest still needs radio range; the QR does not send the password to any server.

WPA vs WEP vs open — what should I pick?

Use WPA/WPA2/WPA3 for almost every home or office network. WEP is legacy. Choose open only when the network has no password. A mismatch with the real encryption type makes scans fail or join incorrectly.

Is the password uploaded?

No. The QR is drawn in your browser from the fields you type. Nothing is sent to Utill.net.

Can I encode a URL instead?

Use the generic QR code generator for URLs and arbitrary text. This page is only for WiFi join codes.

Utill.net

WiFi QRコード生成

SSIDとパスワード

ネットワーク名・パスワード・暗号化から印刷用WiFi QRを作ります。スキャンで接続。ブラウザ内のみ。

この変換はブラウザ内だけで実行され、サーバーへはアップロードされません。

ネットワーク名 (SSID)

暗号化

パスワード

ステルスネットワーク

サイズ: 256px

誤り訂正

ネットワーク名 (SSID)—
暗号化WPA/WPA2/WPA3
サイズ—

WiFi QR を作るにはネットワーク名を入力してください。

URL やテキストの QR が必要ですか？ QRコード生成 — URLとテキスト

このツールについて

A dedicated form for WiFi QR codes. You enter SSID, password, encryption (WPA / WEP / open), and whether the network is hidden. The tool emits the standard WIFI:T:…;S:…;P:…;; string and renders a PNG.

It is not a general-purpose QR encoder. For links or plain text, use the QR code generator.

よくある用途

Print a guest-network card for a cafe, office lobby, or Airbnb
Put the code on a slide so attendees join without typing a long password
Label a travel router so family devices can join after a reset

使い方

Enter the exact SSID (case-sensitive).
Choose encryption and the password (skip password for an open network).
Optionally mark the network as hidden.
Preview, Copy the image, or Download the PNG, then scan-test on a phone.

例

Input	Notes
SSID `GuestWiFi`, WPA, password `example-pass`	Sample button payload; scanners should offer a join sheet.
Open network, SSID `Airport-Free`	`T:nopass` — no password field in the payload.
Hidden SSID with WPA	Adds `H:true;` so the camera can still propose the hidden network.
SSID containing `;` or `\`	Those characters are escaped in the WIFI string; keep the printed QR uncropped.

実務での落とし穴

SSID mismatch: guest networks often have a different name than the main LAN. Encoding the wrong SSID looks fine and still fails to join.
Print size: a 256px PNG stretched across a poster becomes unscannable; keep modules large in physical millimeters.
This is not a Wi‑Fi password cracker and does not talk to your router.

参考資料

最終更新: 2026-08-30

よくある質問

How do phones join WiFi from a QR code?: Most iOS and Android cameras recognize the `WIFI:T:…;S:…;P:…;;` payload and offer to join that network. The guest still needs radio range; the QR does not send the password to any server.
WPA vs WEP vs open — what should I pick?: Use WPA/WPA2/WPA3 for almost every home or office network. WEP is legacy. Choose open only when the network has no password. A mismatch with the real encryption type makes scans fail or join incorrectly.
Is the password uploaded?: No. The QR is drawn in your browser from the fields you type. Nothing is sent to Utill.net.
Can I encode a URL instead?: Use the generic QR code generator for URLs and arbitrary text. This page is only for WiFi join codes.