Short answer: iOS reverts to the built-in keyboard in password fields, number pads, and search bars by design, and it also falls back when a custom keyboard is unloaded under memory pressure or has lost Full Access. Reordering your keyboards to put the custom one first fixes most remaining cases.
You installed a custom keyboard, set it up, used it happily for a day, and now it keeps vanishing. You tap a text field and the built-in keyboard appears. You tap the globe key, get your keyboard back, switch apps, and it is gone again. It feels like a bug in the keyboard you installed.
Usually it is not. iOS has a specific and somewhat unintuitive set of rules about when a third-party keyboard is allowed to appear, how long it stays loaded, and which keyboard the system considers "current" at any given moment. Once you know the rules, the behavior stops looking random, and most of it becomes fixable in about two minutes.
This guide walks through all nine causes, in rough order of how often they are the real answer, with the fix for each.
First, understand how iOS picks a keyboard
Every time a text field becomes active, iOS makes a decision about which keyboard to show. It considers three things: what kind of field it is, which keyboard you used most recently, and whether the keyboard extension you last used is still alive in memory.
That third one is the part almost nobody knows about. A third-party keyboard on iOS is not part of the app you installed it from. It is a separate, sandboxed extension that the system loads on demand and unloads whenever it wants to reclaim memory. When it gets unloaded, iOS has to show something, and the something it shows is the built-in keyboard.
So when your keyboard "switches back to default," one of two entirely different things happened: either iOS decided your keyboard was not permitted in that context, or iOS decided your keyboard was not currently available. The fixes for those two situations are completely different, which is why generic advice on this topic tends not to work.
1. You are in a secure text field
This is the single most common cause, and it is not fixable, because it is a deliberate security decision by Apple.
When an app marks a text field as secure entry, which is what happens in every password box, iOS refuses to show any third-party keyboard. It shows the built-in keyboard instead, with no globe key to switch away. The reasoning is straightforward: a custom keyboard is third-party code that sees keystrokes, and Apple does not want anyone's password passing through it, no matter how trustworthy the keyboard is.
You will see this in login screens, banking apps, PIN entry, Apple ID prompts, and anywhere a developer has flagged the field as sensitive. Some apps are aggressive about it and mark fields secure that you would not expect, like a security answer or a recovery code.
Fix: None, and you should not want one. What you can do is recognize the pattern. If your keyboard disappears only in login screens and comes back everywhere else, nothing is broken. Note that the keyboard returns on its own once you leave the secure field, so there is no need to switch manually.
2. The field is a number pad, phone pad, or decimal pad
The second most common cause looks like a bug and is also intentional. When an app requests a numeric keyboard type, iOS shows its own compact number pad rather than handing the field to a custom keyboard. The same applies to phone-number pads.
This is why your keyboard seems to disappear in a checkout flow, a calculator-style input, an amount field, or a two-factor code box, then reappear the moment you tap a normal text field on the same screen.
Fix: Nothing to fix. But if you rely on dictation for these fields, work around it by dictating the number into a normal text field elsewhere and pasting it in. In practice, numbers are one of the few things typing genuinely beats speaking at, so this rarely costs you anything.
3. Full Access is off, or got turned off
Full Access is the permission that lets a keyboard extension talk to the network and share data with its parent app. Some keyboard features cannot function without it, and dictation is one of them, because audio has to reach a transcription service and text has to come back.
What confuses people is the failure mode. A keyboard without Full Access does not necessarily disappear, but it may load in a degraded state, fail to do the thing you tapped, and leave you reaching for the globe key. That reach is what feels like "switching back."
Full Access can also get switched off without you doing it. It commonly resets after a major iOS update, after restoring from a backup, or after the keyboard is reinstalled.
Fix: Go to Settings, General, Keyboard, Keyboards, tap your keyboard, and confirm Allow Full Access is on. If it is already on, toggle it off and back on. That forces the system to re-register the extension, which clears a surprising number of stuck states. We covered the whole permission model in more detail in how to enable Full Access for an iPhone keyboard, including what the permission does and does not grant.
4. Your keyboard is not first in the list
iOS keeps an ordered list of your enabled keyboards, and the order matters more than the interface suggests. In several situations where the system has to choose a keyboard without a clear "most recent" signal, it walks the list from the top and picks the first eligible one.
If the built-in English keyboard sits above your custom keyboard, it wins those coin flips. You will find yourself switching manually far more often than someone whose list is ordered the other way.
Fix: Settings, General, Keyboard, Keyboards, tap Edit, and drag your custom keyboard to the top of the list. This is the single highest-leverage change on this page for people whose keyboard mostly works but keeps drifting back. If you use only one keyboard, consider removing the others entirely so there is nothing to fall back to except the emoji keyboard.
5. The extension got unloaded under memory pressure
Keyboard extensions run under a much tighter memory budget than regular apps, and iOS terminates them aggressively. If you have been in a memory-hungry app such as a camera, a game, or a photo editor, or you have a very long list of apps in the background, the system may unload your keyboard extension between one text field and the next.
The tell for this one is timing. The keyboard works fine, then after ten or fifteen minutes of heavy use elsewhere it reverts, and it comes back if you switch to it manually. Nothing in Settings changed. The extension was simply not resident when the field became active.
Fix: Close a few background apps and restart the device. A restart clears the most stubborn cases because it resets the extension's state entirely. Beyond that, this is partly a quality-of-implementation issue: keyboards that hold large models or heavy assets in memory get killed far more often than lean ones. If a keyboard reverts constantly on a device with plenty of storage free, the keyboard is the variable, not your phone.
6. The app has its own keyboard behavior
A handful of apps interfere in ways that look like an iOS problem. Some apps dismiss and re-present the keyboard on every screen transition, which forces a fresh selection each time. Some in-app browsers behave differently from the host app. Some apps that heavily customize their text input, including certain messaging and note-taking apps, effectively reset your keyboard choice whenever their compose view rebuilds.
Fix: Test the same keyboard in Notes and in Messages. If it stays put there but reverts in one specific app, the app is the cause and no amount of Settings work will change it. Report it to the app developer, and in the meantime use the globe key once per session in that app.
7. A hardware keyboard is connected
If you have a Bluetooth or Smart Connector keyboard paired, iOS suppresses the on-screen keyboard almost entirely. When it does show something, such as the small floating shortcut bar, that bar is system-provided and is not your custom keyboard.
This trips people up most on iPad, but it happens on iPhone too, and it can persist if a keyboard case is still connected in a bag.
Fix: Disconnect the hardware keyboard, or forget the device in Settings, Bluetooth if you are not using it.
8. An iOS update reshuffled things
Major iOS updates frequently reset keyboard order, and occasionally disable third-party keyboards outright until you re-enable them. This produces the classic "it worked yesterday" complaint that arrives in waves right after a release.
Fix: After any major update, go back to Settings, General, Keyboard, Keyboards and check three things: the keyboard is still listed, Full Access is still on, and the order is still what you set. If the keyboard is missing from the list entirely, add it again with Add New Keyboard. This is worth doing proactively rather than waiting to notice the problem, and it takes under a minute. Related symptoms after updates are covered in dictation not working after an iOS update.
9. The keyboard needs a clean reinstall
If you have worked through everything above and the keyboard still will not stay, the extension's registration with the system may be corrupted. This is uncommon but real, and it usually follows an interrupted update or a restore.
Fix, in this order:
- Settings, General, Keyboard, Keyboards, Edit, and delete the keyboard from the list.
- Delete the parent app from the Home Screen.
- Restart the iPhone. Do not skip this. The restart is what clears the stale extension registration.
- Reinstall the app from the App Store.
- Add the keyboard again, enable Full Access, and drag it to the top of the list.
Deleting and reinstalling without the restart in the middle is the most common reason this procedure "does not work" for people.
The two-minute checklist
If you want to skip the diagnosis and just do the things that fix most cases:
- Settings, General, Keyboard, Keyboards, Edit, drag your keyboard to position one.
- Tap the keyboard, toggle Allow Full Access off, then on.
- Remove keyboards you never use so there is less to fall back to.
- Restart the iPhone.
- Accept that password fields and number pads will always show the built-in keyboard.
That covers causes 3, 4, 5, and 8, which between them account for the large majority of reverting keyboards.
Why some keyboards revert far more than others
Two people can follow identical settings advice and get different results, because not all keyboard extensions are built to the same standard. The variable that matters most is memory footprint.
iOS gives keyboard extensions a fraction of the memory a normal app gets. A keyboard that loads large assets at startup lives permanently close to that ceiling, so the system evicts it early and often. A keyboard that stays lean survives longer between loads, which the user experiences simply as "it stays put."
The same applies to what happens when the keyboard is doing work. A dictation keyboard that tries to hold audio processing entirely inside the extension is fighting for headroom at exactly the moment it can least afford to lose. Architecture that streams the work out instead of buffering it is the difference between a keyboard that finishes your sentence and one that dies mid-recording and drops you back to the default.
This is why we built the Voice Keyboard Pro keyboard extension to stay small and hand heavy lifting off rather than hoarding it. The keyboard gives you a mic button inside any iOS app, and the goal from the start was that tapping it should feel as unremarkable as tapping a letter. If you want the broader setup walkthrough, see our guide to voice typing with a third-party keyboard on iPhone, and if the mic button itself is what has gone missing rather than the whole keyboard, that is a different problem covered in the iPhone dictation mic button missing fix.
Frequently asked questions
Why does my keyboard disappear only in login screens?
Because iOS blocks all third-party keyboards in secure text fields. This is deliberate, applies to every custom keyboard equally, and cannot be turned off. Your keyboard is working correctly.
Can I make my custom keyboard the permanent default?
Not in the way you can on some other platforms. iOS has no single "default keyboard" setting. What you can do is put your keyboard at the top of the keyboard list and remove the ones you do not use, which gets you as close to a default as the system allows.
Does turning off Full Access make my keyboard revert?
It does not remove the keyboard, but it disables any feature that needs the network or shared storage, which for a dictation keyboard means the mic button stops producing text. Most people then switch keyboards manually, which is what makes it feel like reverting.
Why does the keyboard revert after I use the camera?
Memory pressure. Camera and photo apps consume a lot of memory, and iOS reclaims it by unloading extensions, including keyboards. The keyboard reloads the next time you select it.
Will removing the built-in English keyboard break anything?
iOS requires at least one keyboard, and it will keep the emoji keyboard and re-add a system keyboard where one is mandatory, such as secure fields. Removing the English keyboard from the list is generally safe and does reduce accidental switching, but keep it if you ever need the built-in autocorrect behavior.
Is a reverting keyboard a privacy problem?
No. The reverting itself is a memory and permissions behavior, not a data one. Privacy in a keyboard is about what leaves the device and what is stored. On our side, the server keeps only operational pings; no audio and no transcript content is stored.
The bigger picture
Most of the frustration here comes from expecting iOS keyboards to behave like Mac input methods, which stay selected until you change them. They do not. An iOS keyboard is a guest that the system invites in and shows out constantly, and the practical goal is not to stop that from happening but to make the reload fast enough and the permissions solid enough that you stop noticing.
Get the order right, get Full Access on, restart once, and the reverting either stops or narrows down to the two contexts where it is supposed to happen. If it still happens everywhere after that, the keyboard itself is the thing to change.
Voice Keyboard Pro includes a free tier with daily limits, so you can install the keyboard, put it at the top of your list, and see for yourself whether it stays where you put it. Pro is $4.99 per month or $34.99 per year if you decide to keep going.