Cloud and on-device, explained

Hearlex uses two kinds of AI: one that runs on Hearlex's servers (“cloud”), and one that runs directly inside your browser (“on-device”). Here's the difference.

Cloud features

Word definitions, Pro sentence voices, and cloud sentence translation use a larger AI model on our servers. Quality is higher, but each use costs us money, so these features have a daily or monthly limit.

On-device features

Browser text-to-speech and on-device translation run entirely on your computer, using an AI model built into your browser or operating system. They're free with no limit, but need a supporting browser, and quality can be a little lower.

Why there's a limit

Cloud features aren't free for us to run. Daily and monthly limits keep Hearlex's free tier sustainable for everyone; Pro raises them.

What happens when you reach a limit

Hearlex automatically switches to on-device translation or browser voices when it can. If there's no on-device option, you'll see a message asking you to wait until tomorrow or upgrade to Pro.