How to Rewrite Text Anywhere on Mac: The Complete Guide

The short answer

Rewriting text on a Mac usually means one of two things: a fixed "Rewrite" button that does one generic pass, or the copy-paste loop - select the text, switch to a browser tab, paste it into ChatGPT or Claude, write a prompt, wait, copy the result, switch back, paste over the original. Echoo skips both. You select text in any app, press a shortcut, and the rewritten version replaces it in place, using whatever rules you defined for that command.

This guide covers the actual setup: picking or writing a rewrite command, what screen context changes about the result, how far you can customize the prompt, and how to keep the whole thing private if the text is sensitive.

Why the copy-paste loop is the wrong default

Copy, switch app, paste, write a prompt, wait, copy the result, switch back, paste again - that's most of a minute for one sentence. Multiply that by every email, Slack reply, and PR description in a day and it adds up to real, avoidable time, on top of the context-switching that breaks your focus on whatever you were doing before you needed the rewrite.

A system-wide shortcut collapses that to two steps: select, press shortcut. The text comes back rewritten in the same field you were already typing in - Mail, Notion, Slack, a code editor, a form in the browser. There's no list of "supported" apps, because it works at the level of whatever text is active on screen, not inside a specific app's plugin system.

Step 1: pick the rewrite you actually need

Echoo ships with a few common rewrite commands - Professional Tone (opens in new tab) for client and executive writing, Casual Tone (opens in new tab) for messages that should sound relaxed instead of stiff - plus a marketplace (opens in new tab) of community commands for narrower jobs. Start with whichever one matches something you already rewrite by hand at least once a day. That's the one worth putting on a shortcut.

Step 2: turn on screen context for anything that's a reply

A rewrite is only as good as what the model can see. If it only sees the sentence you selected, it has to guess at tone, formality, and what's already been said - and generic guesses are why AI rewrites often feel slightly off.

Screen context is a per-command toggle that changes that. Turn it on and the command also reads what's visible around your selection - the message you're replying to, the thread above your draft - so a reply to a frustrated customer doesn't come back sounding like a reply to a casual coworker. It's most useful for anything that's a reply, and least necessary for standalone writing like a document or a commit message.

Step 3: make the prompt yours

The default commands are a starting point, not the ceiling. Every command is an editable prompt, and the rules worth writing down are specific:

• proofread only - never touch names, dates, numbers, or quoted text
• rewrite for a client: warm, accountable, concise
• keep code, product names, and prices exactly as written
• return the result at roughly the same length, never longer

Save a variant for each context you rewrite into often, each on its own shortcut. A "client email" rewrite and a "quick Slack reply" rewrite shouldn't share one prompt trying to serve both.

Step 4: keep sensitive text off the network

Not everything should go to a cloud model. For anything confidential - HR text, medical notes, legal drafts - route the command through a local model via Ollama instead of a hosted API, and the text never leaves your Mac. API keys for hosted providers are stored in Apple Keychain rather than in a plain config file. See how Echoo handles your data (opens in new tab) for the full breakdown.

Try it on one real message

Pick the next email or Slack reply you'd normally rewrite by hand. Select it, run your command, and check names, numbers, and the actual ask before you send - the rewrite handles the wording, you keep the final read. If you're deciding between this and a passive grammar checker, Echoo vs Grammarly (opens in new tab) covers where each one fits.