ThumbFree: free voice typing for Android and iPhone that runs fully offline

What's going on

When you dictate on your phone instead of typing, your voice usually ends up on a server: the built-in dictation in major keyboard apps often processes speech in the cloud. The developer behind the GitHub account kabrapratik28, who posted the project on Reddit's r/LocalLLaMA, didn't want that, so he built ThumbFree. The app adds voice input to any app on Android and iPhone, and the speech recognition itself runs entirely on the phone.

Under the hood, ThumbFree uses NVIDIA's Parakeet speech recognition model with 0.6 billion parameters. You download the model once. After that, the developer says, the app doesn't need an internet connection and even works in airplane mode. ThumbFree is free, and the source code is released under the Apache 2.0 license, which also allows commercial reuse.

Here's where to get it:

• Android: Google Play
• iPhone: App Store
• Source code plus speed and accuracy benchmarks: github.com/kabrapratik28/ThumbFree

How it works on Android and iPhone

ThumbFree works differently on the two platforms, because Google and Apple give developers different levels of access.

Android: When you tap a text field in any app, a small bubble appears next to it. Tap the bubble to start recording, speak, tap again to stop, and the recognized text is inserted into the field. The upside: you keep your usual keyboard. ThumbFree doesn't replace Gboard, SwiftKey or whatever keyboard you use. It sits on top as an extra tool.

iPhone: Here, ThumbFree is a separate keyboard with a microphone button. But Apple doesn't let keyboard extensions access the microphone. The developer works around this: the first time you tap the mic button in a session, the ThumbFree app briefly opens and you swipe back to the app you were in. After that, recordings start instantly. It's a bit clunkier, but only the first time in each session.

How fast it is

On phones, local speech recognition is mostly a question of speed, since a phone has far less computing power than a data center. The developer reports these numbers from his own devices:

These figures come from the developer himself. There are no independent tests yet. He says he has published speed and accuracy benchmarks in the GitHub repository that you can check for yourself. On older or less powerful devices it will likely take longer. The Reddit post doesn't say how much longer.

The model behind it: NVIDIA Parakeet

Parakeet is a family of speech recognition models (ASR, short for "automatic speech recognition", meaning the automatic conversion of spoken language into text) that NVIDIA releases with freely downloadable weights. At 0.6 billion parameters, the variant used here is small enough for a phone and is still considered very accurate. The better-known option in this space is OpenAI's Whisper, which many local dictation apps use.

ThumbFree recognizes English by default. A second model covers 25 European languages, very likely including German, French and Spanish. The Reddit post doesn't list the individual languages, so test your own language yourself to see how well it works. The model file is around 0.5 to 0.7 GB, so you'll need that much free storage on your phone.

Privacy: what the app says it doesn't do

The developer promises no account, no ads and no analytics tools. The only download is the model. Your voice and your text stay on the phone. Because the code is open, you can verify that in principle. That's the key difference from closed apps, where you simply have to take such promises on trust.

Keep one thing in mind: local speech recognition only protects the step from your voice to text. What happens to the text after that is up to the app you're typing into. If you dictate a search query with ThumbFree, it still goes to the search engine, of course.

Requirements

• Android: version 13 or later
• iPhone: iOS 26 or later
• Storage: around 0.5 to 0.7 GB for the model
• Internet: only once, for the model download

A note for Android users: the bubble next to text fields probably needs special system permissions, such as accessibility access or permission to draw over other apps. The post doesn't give details. Permissions like these are powerful, which is exactly why the open source code is a plus here.

Our take

Offline dictation on phones isn't new: the FUTO Keyboard on Android also offers local voice input, for example, and Apple and Google now handle some processing on-device too. But ThumbFree has two things going for it. On Android, you don't have to switch keyboards, and Parakeet is a current, highly accurate model that's fully verifiable thanks to open weights and open code. Running on both major platforms is also fairly rare for a hobby project.

Plenty is still unclear. The speed numbers come from the developer and from two current flagship devices. Independent measurements of recognition quality are missing, especially for languages other than English. On iPhone, Apple's microphone block for keyboards makes the experience a compromise. And as with any one-person project, whether the app keeps getting updates depends on the developer's commitment. Still, if you don't want to send your voice to a server, you can try ThumbFree today for free and with no risk.