How Lexter works

Lexter lives in your menu bar. Select text in any app, press a shortcut, and read the translation right where you work.

Part 1Translation in every edition, Free included

Quick start

Install. Open the downloaded .dmg and drag Lexter to Applications. Start it from there: Lexter needs to run from the Applications folder.
Allow Accessibility. On first launch macOS asks to let Lexter control your computer. This is how Lexter reads the text you select and shows its window next to it. Turn Lexter on in System Settings → Privacy & Security → Accessibility.
Find the menu-bar icon. Lexter has no Dock icon: it sits in the menu bar at the top of the screen. Click it for the menu and Settings.
Translate. Select a sentence anywhere (a web page, a PDF, an email) and press ⌃⌘B. The translation appears right next to the text.

Two engines. Out of the box Lexter uses Apple Translation, built into macOS: free and unlimited. For more languages and better wording, download an on-device AI model. Both run on your Mac.

Four ways to translate

⌃⌘B

Quick translation

A small bubble with the translation appears next to the selected text. No window to open or arrange.

Press ⌃⌘B again while the bubble is open to replace the selected text with the translation, handy when you write a reply in another language.

⌃⌥⌘B

Translation window

A floating window with the original and the translation. Change the languages, copy the result, listen to it with your Mac's voices, or pin the window so it stays on top while you work.

⌃⌥O

Text on the screen

For text you cannot select: a picture, a scanned page, a dialog. Drag over an area of the screen; Lexter recognizes the text in it and translates it. macOS may ask for Screen Recording permission the first time.

⌃⇧⌘B

Lexter window

Opens Lexter's own window, where you can paste or type any text and translate it.

AI models

An AI model translates more languages (35+) and keeps the tone of the text better than Apple Translation. It is downloaded once and then runs entirely on your Mac, without the internet.

Choose one in the menu-bar menu under Model, or in Settings → Translation:

Model	Download	Good for
Qwen3 1.7B	≈ 1 GB	Fast and light, Macs with 8 GB of memory
Qwen3 4B · Gemma 3 4B	≈ 2.5 GB	The best balance for most Macs
Qwen3 8B	≈ 4.6 GB	The best quality, Macs with 16 GB of memory or more

A model takes memory only while you use it: when you stop using it, Lexter unloads it and frees the memory again (you can choose how soon in Settings → General). Apple silicon (M1 or later) is recommended.

Part 2Improve Text Pro only in Lexter Pro

How Improve Text works

Lexter Pro also improves your own writing, in the same language, without changing what you mean.

⌃⌥I

Improve in place

Select your text in any app and press ⌃⌥I. Lexter suggests a better version right there.

⌃⌥C

Improve Text window

Paste or write a draft, pick how much may change with the slider, then press ⌥↩ to improve and ⌘↩ to accept the result (it is copied to the clipboard).

Five levels, from minimal fixes of typos and grammar to an expressive rewrite.
Word-by-word diff: you see exactly what changed before you accept it.
Meaning guard: Lexter warns when numbers, names or terms changed.

Improve shortcuts

Improve the selected text in place	`⌃⌥I`
Open the Improve Text window	`⌃⌥C`
In the window: improve the draft	`⌥↩`
In the window: accept the result (copied to the clipboard)	`⌘↩`

Part 3Settings and help

Settings and shortcuts

Open Settings from the menu-bar icon or with ⌘, while a Lexter window is active.

General: interface language, memory use of the models, and your license.
Translation: the AI model and the translation shortcuts.
Improve Text: its own model (by default the same as for translation) and its shortcuts.

Every shortcut can be changed: click it in Settings and press a new one. The translation defaults (for Improve Text see Improve shortcuts):

Quick translation	`⌃⌘B`
Translation window	`⌃⌥⌘B`
Lexter window	`⌃⇧⌘B`
Translate text on the screen	`⌃⌥O`

Free, Standard and Pro

Free, with no time limit: Apple Translation without limits, and AI translation up to 1,000 characters a day.
Standard: unlimited AI translation.
Pro: everything in Standard plus Improve Text.

Prices are on the pricing page. After you buy, you get a license key: enter it in Settings → General → License and press Activate. It works on every Mac signed in to your Apple ID.

Privacy

Lexter has no account and no analytics. Your texts are translated and improved on your Mac and never sent anywhere. The internet is used only to download the AI models (from Hugging Face), to check for updates, and to activate a license.

If something does not work

A shortcut does nothing: Check that Lexter is on in System Settings → Privacy & Security → Accessibility. If it is, another app may use the same shortcut: set a different one in Lexter's Settings.
AI translation says the helper is unreachable: Lexter must run from the Applications folder. Move it there, quit it and open it again.
The daily limit is reached: Apple Translation keeps working without limits. For unlimited AI translation, see the plans; the free limit starts again the next day.
A model download fails: Check your internet connection and free disk space, then start the download again from Model in the menu.
Something else: Write to support@nukatools.app.