Grammar and tone in your language.

On Mac and Windows, the apps where you can select text: select, press the shortcut, then review. Marks as you type are on wherever DuoTyping can mark your text, except in password managers, code editors, terminals, banking apps and browsers, and you turn them off for an app, or pause them, from the mark beside the text. In Chrome and Edge, right-click checks on any site, and marks as you type and the Rewrite pill are on every secure site except password managers, code editors, terminals and sites ending in .bank; you turn them off for a site, or pause them for an hour, from DuoTyping’s toolbar button. Google Docs isn’t supported. For anything else there’s Write, on the web and your phone.

A Mac with macOS 14 or later, Apple silicon or Intel; a PC with Windows 10 22H2, or Windows 11 24H2 or later; Chrome 119 or later, or Edge. Write runs in any current browser, phones included.

For DuoTyping’s own checks, yes: a free one, which gives you 20 checks a day in the Mac and Windows apps, the browser extension and Write on the web. Your own key, on Mac and Windows, needs none. To try DuoTyping first, check a few sentences on this page with no account.

DuoTyping’s own checks are free every day with a free account, and you can try them on this page without one. Pro, with more, is US$10 a month or US$96 a year. Tax may apply at checkout. Spelling marks are never counted. On your own key, your AI service bills you directly.

DuoTyping Engine, unless you choose otherwise: DuoTyping’s server and an AI model run by a company DuoTyping works with. On Mac and Windows you can use your own key with OpenAI, Anthropic or any OpenAI-compatible endpoint; it stays in your Mac’s Keychain or protected by Windows, and DuoTyping never sees it. The browser extension and Write always use DuoTyping Engine.

With DuoTyping Engine, DuoTyping keeps what it checks and translates, encrypted, to improve DuoTyping, and never sells it. On your own key, checks go straight to your AI service and DuoTyping keeps none of them; translations always go through DuoTyping, so it keeps those. Delete Account, in the web app, deletes your account after 90 days; what was kept stays, no longer linked to you. The Mac and Windows apps also send anonymous counts of which apps marks as you type work in, never your text; turn them off in Settings › About.

No: checks and translations need a connection. Pronounce works offline in the Mac and Windows apps, drafts in Write stay on your computer there, and Write on the web keeps editing offline and saves once you’re back.

Yours. DuoTyping checks grammar and tone in the language you write in, and keeps its suggestions in that language. Translate takes your language into the one you need, and back, and Pronounce reads each word in its own language. The apps’ own buttons and menus are in English.

It’s how macOS lets one app read the text you select in another and write an accepted change back in place, and, while marks as you type are on, read what you type to mark it. DuoTyping never reads password fields or password managers. Without it, you can still type or paste into Write.

Only the text box you’re typing in and the text you select, on every secure site: Chrome or Edge asks you to allow that when you add it, or once when it updates. It sends nothing until you sign in, and then only to DuoTyping. It never reads password, card-number or one-time-code fields, password managers, DuoTyping’s account pages, incognito windows or the browser’s own pages; on code editors, terminals, sites ending in .bank, plain http pages and the sites you turn off, it reads only text you ask it to check.