Open source · Bring your own key

Improve your English
in any app.

Select text, press a hotkey, pick a preset. BrushUp rewrites your English to sound natural, correct, or professional — right inside Outlook, Slack, Word, or whatever you're typing in.

Windows 10/11 No account MIT licensed
01 — Workflow

Three keystrokes from typo to polished.

No copy-paste. No tab-switching. The popup floats above your work and dies the moment you're done.

STEP 01

Select your text

Highlight a sentence, paragraph, or whole draft in any application — email, chat, document, or browser.

↳ works via Windows UI Automation
STEP 02

Press the hotkey

Hit your shortcut (default: Ctrl+Alt+R). A floating popup snaps open with your captured text.

CtrlAltR
STEP 03

Pick a preset, replace

Choose Fix Grammar, Make Formal, Translate to EN — anything. Hit Enter to rewrite, Enter again to replace.

17 pick preset
02 — Built for the keyboard

Quiet, fast, and never in your way.

Designed for non-native English speakers who type all day. Mouse-free, account-free, and entirely under your control.

Works everywhere

UI Automation captures text from any app — Outlook, Word, Slack, Notion, browsers, even legacy apps. Clipboard fallback included.

Streaming rewrites

Watch the improved text arrive token by token. Cancel anytime if the rewrite goes sideways.

Side-by-side diff

See exactly what changed. Deletions struck through in red, additions highlighted in green. No mystery rewrites.

Undo replace

Replaced the wrong thing? Hit Ctrl+Z and the original text snaps back into the source app — instantly.

API key in OS keychain

Your API key is stored in Windows Credential Manager — never in a plain-text config file, never sent anywhere except your chosen provider.

Bring your own provider

OpenRouter, Ollama Cloud, or any OpenAI-compatible endpoint. Swap models anytime — Claude, GPT, Gemini, open-source. Your call.

03 — Presets

Seven presets out of the box. Customize freely.

Each preset has a carefully tuned system prompt. Edit them, add your own, or delete what you don't use.

Improve English
Make it sound native
1
Fix Grammar
Correct mistakes only
2
Make Formal
Business tone
3
Make Casual
Friendly tone
4
Simplify
Shorter, clearer
5
Translate to EN
Any language → English
6
Make Polite
Soften the tone
7

Start writing better today.

Free, open source, and runs quietly in your system tray. No account, no telemetry, no nonsense.