Third-party keyboard not showing on iPhone
Seven causes, from the cached Settings screen to secure text fields and memory pressure, and how to tell them apart.
“I installed a keyboard and it is not there” is really several different problems wearing the same clothes. Work through them in this order — the first two account for the large majority of cases and take seconds to rule out.
1. It was never added in Settings
This is the most common one by a wide margin. Installing a keyboard app does not activate its keyboard. Go to Settings → General → Keyboard → Keyboards → Add New Keyboard… and tap it under “Third-Party Keyboards”. If it is already in your list, move on.
2. The Settings screen is showing a stale list
iOS caches the Add New Keyboard list aggressively. If you install an app and go straight into Settings, the new keyboard often is not there yet. Open the keyboard app once, then swipe Settings fully out of the app switcher and reopen it. The entry appears. Rebooting achieves the same thing and is the sledgehammer version.
3. You are typing in a secure text field
Password fields, payment sheets and some banking screens mark themselves as secure. iOS then forces Apple’s keyboard for as long as that field has the cursor, and the globe key will not move you off it. This looks exactly like your keyboard “disappearing”. Tap into a normal field — a note, a message draft — and if your keyboard comes back, this was it. Nothing is wrong and there is no fix, because this restriction is what keeps your password away from third-party code.
4. The globe key is not where you expect
On iPhones with Face ID, the globe key sits bottom-left, sharing the row with the emoji key. A single tap advances to the next keyboard in the order set in Settings; press and hold to get a picker instead. If you have four keyboards enabled and yours is last, a single tap will appear to “do nothing useful” three times. Reorder the list (Settings → General → Keyboard → Keyboards → Edit) so your keyboard is early.
5. Memory pressure killed the extension
Keyboard extensions run under a much tighter memory limit than a normal app — tens of megabytes, not hundreds. If a keyboard exceeds it, iOS terminates the extension and instantly falls back to the system keyboard mid-sentence. Symptomatically: your keyboard shows for a fraction of a second, then flips to Apple’s. It is more likely on older devices, in memory-hungry host apps, and with keyboards that load large images.
You cannot raise the limit, but you can reduce the pressure: close other apps, and if the keyboard offers a photo background, try turning it off. A well-built keyboard downsamples images on import so the extension never decodes a full-resolution photo, but not all of them do.
6. A stuck extension after an app update
After an app updates in the background, the old extension can stay registered while the new one is not yet loadable. Remove the keyboard in Settings (Edit → minus → Delete), then add it again. This re-registers the extension without deleting the app or your settings.
7. Something deeper is wrong with the keyboard state
If nothing above helps, Settings → General → Transfer or Reset iPhone → Reset → Reset Keyboard Dictionary clears the learned-words store and the keyboard state that goes with it. It costs you your typing dictionary and nothing else — no photos, no apps, no accounts. Add the keyboard again afterwards.
A quick decision list
- Not in the Add New Keyboard list at all → cause 1 or 2.
- In the list, but the globe key never reaches it → cause 4.
- Appears everywhere except one screen → cause 3.
- Appears then vanishes within a second → cause 5.
- Worked yesterday, stopped after an update → cause 6.
- None of the above → cause 7.
Where Kibo fits
Kibo is a free custom keyboard for iPhone with mechanical key sounds, 56 themes and 15 backlight effects. It is built to stay inside the extension memory budget — the emoji and kaomoji panels are text rather than image assets, and photo backgrounds are downsampled once in the main app so the keyboard never touches a full-size image. Full Access can stay off.
Frequently asked questions
Why does my keyboard revert to Apple’s in my banking app?
That app marks its fields as secure. iOS forces the system keyboard on secure fields and no third-party keyboard can override it. This is intended behaviour, not a bug in the keyboard.
My keyboard flashes on screen then disappears. What is that?
Almost certainly the extension being terminated for exceeding the keyboard memory limit. Close background apps and disable any photo background the keyboard offers, then try again.
Will resetting the keyboard dictionary delete anything important?
It clears learned words and autocorrect history only. Your apps, photos, messages and accounts are untouched.
Try it on your own keyboard
Kibo is a free custom keyboard for iPhone with 17 mechanical key sounds, 56 themes and 15 backlight effects. No account, no ads, and it works with Full Access left off.