DuoFlickPrivacy policy
October 27, 2026. This is a translation of the Japanese policy; if the two differ, the Japanese version applies.
DuoFlick (the iPhone app and the Japanese keyboard it includes) collects no information about the people who use it, and never sends what you type anywhere. Only the app connects to the internet, and only in two cases: when you share a layout with a link (including opening a shared layout link), and when you send something with “要望・不具合を送る” (Send feedback). The keyboard never connects to the internet.
Information we collect
We collect no information about you. There is no account to sign up for, and the app has no advertising or usage analytics. The only things sent to our server are those described below under “Sharing layouts” and “Sending feedback.”
What you type
Text you type with the keyboard is never sent outside your iPhone. Kana to kanji conversion uses the dictionary and conversion engine on your iPhone.
If you turn on “AIで変換を賢くする” (Smarter conversion with AI) in the app, a small AI model included in the keyboard uses the text before the cursor to pick conversions. This model also runs only on your iPhone, and never saves or sends the text it reads. It’s off by default.
What is stored on your iPhone
The following are stored only on your iPhone and are never sent anywhere.
- Keyboard settings
- Layouts you make
- Conversion learning (a record of the conversions you use often, so they come up first)
You can erase conversion learning with “学習をリセット” (Reset learning) under “変換” (Conversion) in the app. Deleting the app erases all of these.
Full Access
Full Access for the keyboard is optional. If you allow it, you get haptics and key sounds, and the side you pick with ⇄ on the keyboard (left, none, or right) is also saved to the app’s settings. Even with Full Access, the keyboard never connects to the internet. Every typing feature works without it.
Sharing layouts
When you use “リンクで共有” (Share link) or “リンクをコピー” (Copy link) in the app, the layout is sent to the DuoFlick server (duoflick.hanabi.jp) to make a short link. Only the layout’s name and its settings, such as the position, size, and color of the keys and the candidate bar, are sent. Nothing that identifies you or your device is sent with it.
Anyone who has the link can view a layout stored on the server. Layouts are deleted automatically about two years after they were last shared. Please don’t put anything private in a layout’s name.
To prevent large numbers of uploads in a row, the IP address of the sending device is used briefly. IP addresses are not stored. The server runs on services from Cloudflare, Inc.
When you open a shared short link, DuoFlick loads that layout from the server.
When you’re offline, the app makes a long link that contains the layout itself. In that case, and when you share a layout as a file, the layout isn’t sent to the server and goes only to the people or places you choose.
To have a layout removed from the server, contact us at the address below and include the link.
Whichever way you share, you are the one who sends it. DuoFlick never sends layouts on its own.
Sending feedback
When you send something with “要望・不具合を送る” (Send feedback) in the app, what you wrote is sent to the DuoFlick server (duoflick.hanabi.jp). For conversion requests, the reading and the word you entered are sent too.
Along with it, the app sends its version and build, the iOS version, the device model (an identifier such as iPhone19,4), the kind of layout you use, and whether the keyboard has been added. It doesn’t send anything you typed with the keyboard or anything that identifies you. Layouts you made are sent only as “your own layout,” not by name.
We use what you send only to improve DuoFlick, and it is deleted automatically after about a year. To prevent large numbers of submissions in a row, the IP address is used briefly. IP addresses are not stored.
Changes to this policy
When we change this policy, we update this page and the date at the top.
Contact
Email contact@hanabi.jp. For help using the app, see the support page.