Private and offline Android keyboards, compared

Last updated: 2026-07-26

If you want an Android keyboard that does not ship what you type to a server, there are a handful of real options and a lot of marketing copy in the way. This compares six of them: Lexo, Gboard, Microsoft SwiftKey, FUTO Keyboard, HeliBoard, and AnySoftKeyboard. I make Lexo, so the section you should read most carefully is the one about where Lexo loses.

The three questions worth asking

Most "private keyboard" comparisons turn into a feature checklist. Only three things actually decide this:

• What leaves the phone, and is it on by default or opt-in? "We don't sell your data" is not an answer to this.
• What still works with the network off? A keyboard whose good features need a server is a thin client, whatever the listing says.
• Can you check it yourself? Two things make a privacy claim checkable: published source, or a permission set small enough that a packet capture settles the argument.

The short version

• You want a claim you don't have to trust anybody for: HeliBoard. It ships without the internet permission at all, which is the strongest form of this claim that exists.
• You want open source plus swipe and offline voice from one vendor: FUTO Keyboard.
• You want the polish and the ecosystem and you're fine with Google: Gboard.
• You're deep in a Microsoft account already: SwiftKey.
• You want a long-lived, permissive-licensed, no-network keyboard with plenty of knobs: AnySoftKeyboard.
• You want a neural suggestion model and offline dictation inside one keyboard, on the phone, and will pay once: Lexo.

Lexo

com.lexo.keyboard, closed source, free to install with a one-time $9.99 unlock for the parts worth having. No subscription and no ads.

Typing suggestions run Qwen2.5-0.5B-Instruct, quantized to q8_0 (a 531 MB GGUF file), through llama.cpp on CPU inside the keyboard process. Dictation is an NVIDIA Parakeet transducer, int8 ONNX, decoded through sherpa-onnx, also on the phone. Transcript cleanup is a small ELECTRA-based tagger with three heads plus a deterministic rule pass, not a generative rewrite, so it fixes fillers, casing and punctuation but will not restructure your sentence.

Unpaid, you get a word-frequency prior plus your own personal vocabulary, which is table stakes for any keyboard. The $9.99 unlock turns on the neural tier and dictation, both of which run locally, and it's a one-time payment. There's a 30-day trial covering both, seeded when you finish setup; after it expires you're back to the word-frequency tier unless you buy. I'd rather call that a demo than a free tier, because everything that would make you switch is on the paid side of the line.

The app declares five permissions: RECORD_AUDIO, VIBRATE, POST_NOTIFICATIONS, INTERNET, ACCESS_NETWORK_STATE. INTERNET covers exactly three things and none of them is your text: a one-time model download of about 1.2 GB on first run, Google Play billing for the unlock, and anonymous crash reporting through Firebase Crashlytics. Crash reporting is off unless you turn it on. The toggle is at Settings > Advanced > Other > Send crash reports. Crash reports carry stack traces, device model and app version, never what you typed or said.

Gboard

Google's keyboard, closed source, free, preinstalled on most Android phones.

Google's own "Learn how Gboard gets better" page (read 2026-07-26) is the useful document here. On federated learning it says it "doesn't send the text you speak or type to Google, but will send what it learns to Google," where it is combined with what other people's phones learned. On audio it describes an opt-in donation: "snippets of your audio input on Gboard are sent to and stored by Google to improve speech recognition."

Google's advanced voice typing page (read 2026-07-26) is more specific than most people expect, and worth crediting: "The text you speak stays on your device and isn't sent to Google servers except when you use the 'Fix it' or detailed edits features." That page also says advanced voice typing needs "Pixel 6 or up" and lists English, French, German, Italian, Japanese and Spanish.

So Gboard's on-device story is real on recent Pixels and better than its reputation. What you can't do is verify it. It's closed source, it's wired into Play services, and its permission set is large enough that a packet capture won't tell you much. You are trusting Google's description of Google's software. That's a reasonable thing to do or not do; it just isn't the same kind of claim as HeliBoard's.

Microsoft SwiftKey

Microsoft's keyboard, closed source, free.

Microsoft's support page "What data is collected / sent while using Microsoft SwiftKey Keyboard" (read 2026-07-26) says anonymous usage stats "are periodically sent back," described as meta-level counts rather than content, and that "if the app crashes, anonymous info about the crash will be sent to Google and to us." Signing in raises the ceiling: "If you create a Microsoft SwiftKey Account, various additional data can be transferred to our servers." With Backup and Sync on, "you give explicit permission for your personal language model data to be stored on our servers and processed to ensure prediction consistency between your devices."

Read plainly: the defaults are modest, the sync feature is the part that moves a model of how you write off your phone, and it is opt-in. Same verifiability problem as Gboard.

FUTO Keyboard

FUTO's keyboard is the closest thing to Lexo in intent, and in several ways it's ahead.

Their site (keyboard.futo.tech, read 2026-07-26) leads with "100% Offline, 100% Private," links the source on GitLab, and sells a license as "a one-time payment" with "No recurring subscriptions," while the app itself is available free on Play and F-Droid. It advertises swipe input ("FUTO Swipe"). Their separate voice input app is described as "designed to work entirely on-device with no data stored," and the same license covers both.

One caution, and it cuts in FUTO's favor more than against it: I have not audited their license terms, and "source published on GitLab" is not automatically the same thing as an OSI-approved open source license. If that distinction matters to you, read the license rather than taking my word or a comparison table's word for it.

HeliBoard

HeliBoard's README (read 2026-07-26) contains the single strongest sentence in this whole comparison: it "does not use internet permission, and thus is 100% offline." It's GPLv3, with Apache-2.0 code inherited from the AOSP keyboard lineage.

An app without the internet permission cannot send your text anywhere. Not "promises not to." Cannot. No packet capture needed, no trust required, no privacy policy to parse. If that is your priority, this is the answer and nothing here beats it.

The tradeoff is what it doesn't do. Nothing in the README describes a neural suggestion model or built-in dictation, so voice typing means installing a separate voice input app, and prediction quality is a different class of thing than a language model produces.

AnySoftKeyboard

The elder statesman here, going back to 2009. The GitHub README (read 2026-07-26) states Apache-2.0, puts "NO internet access" in the headline, and lists gesture typing, voice input, and an incognito mode that "will not learn new words, will not keep history of what was typed."

Since the app itself has no network access, its voice input is handing off to whatever recognizer your phone provides, which means the privacy question for dictation is really a question about that other component. Same shape as HeliBoard: very checkable, deliberately not trying to run a model.

Where Lexo loses

If you skipped here first, good instinct. This is the part a comparison written by a vendor usually leaves out.

• It's closed source. HeliBoard and AnySoftKeyboard are open, FUTO publishes source. Lexo doesn't. The privacy claim is checkable by packet capture and a five-permission manifest, but that is a weaker guarantee than reading the code, and I'm not going to pretend otherwise.
• "No internet permission" beats anything I can say. Lexo declares INTERNET and always will, because of the model download and the paid unlock. HeliBoard's claim is categorically stronger than mine.
• Crash reporting exists, and it is opt-in. Nothing is sent unless you turn it on at Settings > Advanced > Other > Send crash reports, and reports never carry typed text or audio. It shipped on by default in earlier builds and was changed to opt-in, which is worth saying rather than quietly claiming it was always this way.
• De-Googled ROMs are out. Play Integrity currently blocks installing Lexo on GrapheneOS and LineageOS, and the purchase path needs Play services. If you're on a custom ROM, HeliBoard, AnySoftKeyboard and FUTO are on F-Droid and Lexo is not an option today.
• Swipe typing isn't shipped yet. Glide is written and merged, decoded by a neural classifier rather than a lookup, but the Play build doesn't have it. If swipe is the main way you type, Lexo is not the keyboard for you today, and I'd rather say that than let you find out after installing 1.2 GB.
• It's a big install. About 1.2 GB of models on first run, and the 531 MB typing model is resident when the neural tier is active. On an older or storage-tight phone that's a real cost.
• Language coverage is narrow. English is strongest. Spanish, Portuguese, Swedish, German and French also ship. Arabic dictation is broken right now. Gboard's language list is not close to comparable.

How to check any of this without trusting the vendor

• Read the permission list in Android's app info or on the Play listing. A keyboard with no internet permission ends the conversation immediately. A keyboard with a long list needs a better explanation than a marketing page.
• Turn the network off and type. Whatever still works is genuinely local. Anything that degrades was never on your phone.
• Point NetGuard or PCAPdroid at it and type for a while. For Lexo specifically, here is what you should expect: the one-time model download, then nothing while you type or dictate, plus a Crashlytics heartbeat until you switch crash reporting off. If you see anything else, I want to hear about it.

So which one

If verifiability is the whole point for you, take HeliBoard or AnySoftKeyboard and accept simpler predictions. If you want open source with modern features, FUTO. If you're on a Pixel and happy with Google, Gboard's on-device voice typing is genuinely good and I'd rather say so than pretend. If you want a language model doing your suggestions and an offline transducer doing your dictation, inside one keyboard, and you'll pay $9.99 once for it, that's Lexo on Google Play.

More detail on the model side: running a 0.5B language model inside an Android keyboard, and what offline dictation on Android actually means.