Install a third-party keyboard on an iPhone and you meet a switch called Allow Full Access, with a warning that the keyboard could transmit what you type. Most people either turn it on without reading or leave it off and lose the feature they installed the keyboard for. Neither is a good way to decide.
Here is what the switch controls, according to Apple's own documentation, what it never touches, and how to check it for every keyboard on your phone.
What a keyboard can do with Full Access off
Every third-party keyboard runs as an extension: a small program in its own sandbox. Apple's developer documentation, Configuring open access for a custom keyboard, lists what that sandbox allows when Full Access is off:
- Everything a basic keyboard does, including word suggestions and your text shortcuts from Settings
- Its own storage, plus read-only access to storage it shares with its own app
- No network access
- No access to the microphone and speaker
Apple's summary is that, with Full Access off, your keystrokes go only to the app you are typing in. A keyboard whose whole job is typing does not need Full Access at all.
What Full Access adds
Turning the switch on lets the keyboard do more, and Apple lists what:
- Send keystrokes and other input to a server for processing
- Share storage with its own app, so settings and saved items stay in sync
- Ask for Location Services and Contacts, each still behind its own permission prompt
- Use iCloud to keep its settings up to date on your other devices
The first item is the one that matters. A keyboard that writes replies with cloud AI, checks grammar on a server, or syncs with an online account needs Full Access to do it. There is no way around that on iOS.
So the real decision is not about Full Access in the abstract. It is whether you trust this developer with what gets sent once the door is open.
What it never touches
This is the part most explanations skip. Whether Full Access is on or off, iOS uses its own keyboard in some places. Apple's App Extension Programming Guide lists them:
- Password and other secure fields. When you tap a field that shows what you type as dots, the system temporarily replaces the custom keyboard with its own, and switches back when you leave the field.
- Phone number pads, such as the number fields in Contacts.
- Apps that opt out. A developer can refuse custom keyboards in their app. Apple gives a banking app as an example.
So the fear that a keyboard could read your banking password is closed off by the platform, for every third-party keyboard. The question that is left is narrower: what happens to your everyday typing, the messages, emails and notes, once a keyboard is allowed to send it somewhere.
How to check every keyboard on your phone
- Open Settings.
- Tap General, then Keyboard.
- Tap Keyboards to see every keyboard you have added.
- Tap a keyboard from another developer to see its own Allow Full Access switch.
The same Keyboards screen is where you add a keyboard with Add New Keyboard and remove one by swiping left and tapping Delete. If you are setting one up for the first time, the full walk through is in How to add a keyboard on iPhone.
What happens when you turn it off
Switch Full Access off and the keyboard loses network access. Anything it did on the phone keeps working: typing, its own suggestions, switching keyboards with the globe key. Anything that needed a server stops until you turn the switch back on.
That makes it easy to test a keyboard. Leave Full Access off for a day, see what still works, and turn it on only if you want the features that need it.
Five questions before you allow it
- Does the developer say what triggers a network request: only when you tap an AI feature, or all the time?
- Is there a separate switch in the app for AI processing, beyond Full Access itself?
- Does the privacy policy say what leaves your phone: only the text you are working on, or a wider slice of the conversation?
- Can you keep details like phone numbers, email addresses, links and one-time codes out of what is sent?
- Does it work without an account, or does everything you type sit under a login?
None of these needs you to trust a marketing page. Legitimate developers answer them in the privacy policy or in the app's settings, and a developer who cannot answer them plainly has told you something useful.
How Protexter splits it, as one example
Protexter, the keyboard this site is about, shows how the split plays out in practice.
With Full Access off, it still types, and its cloud AI features ask for Full Access instead of sending anything. With Full Access on, third-party AI processing is still a separate switch in the app, off by default, on a screen that names the companies involved. Conversation context and automatic contact memory are two more switches, each off by default.
By default, phone numbers, email addresses, links and one-time codes are redacted from conversation context, and you can turn that off when you need the exact details. Text in a screenshot is read on your phone, and there is no account to create. For the wider question of whether an AI keyboard is safe to use at all, see Is it safe to use an AI keyboard on iPhone?.
The short version
Allow Full Access is mostly a network switch, plus shared storage, iCloud, and the chance to ask for your location and contacts. iOS protects passwords and secure fields whatever you choose. The useful habit is to check, for each keyboard, what triggers a network request and what leaves your phone when it does, and decide from there.