Your AI shortcut for every app

Fix anything you write. Anywhere. Instantly.

Select text. Press a shortcut. Fix, rewrite, translate, or summarize in any app — no tab switching, no copy-paste.

Get Keystro for Windows

Free plan · No setup · 30s install

Watch 60s demo▶
BeforeAfter
To:team@company.com
Subject:about the project updetAbout the Project Update
Hi team,

i hope ur doin good. just wanted to chek about the updet. some issue need fixd b4 the deadline. should meet asap.

regards, jhon
Hi team,

I hope you're doing well. I wanted to check about the update. A few issues need to be fixed before the deadline. We should meet as soon as possible.

Best regards, John
12 issues detectedspelling • grammar
✓0 errors — polishedready
Ctrl+Shift+C
⚡Fixed in seconds🗣️Keeps your tone📝Uses your vocabulary

60-second product demo

See the shortcut flow before you install.

From the ChatGPT copy-paste detour to a two-second correction in the app where you already work — Correct, Draft Email, and Ask follow the same pattern.

Keystro 60s product demo
Preview
Outlook — new messageCtrl + Shift + H

hey, could we reschdule the meeting on thursdey? i had a conflit with another client

▶

Hey, could we reschedule the meeting on Thursday? I had a conflict with another client.

What you'll see

  1. 1The cost of copy-paste and tab-switching
  2. 2Select text where you already work
  3. 3Press one keyboard shortcut
  4. 4Watch the result replace your selection in place
  5. 5Draft Email and Ask work the same way
  6. 6Privacy: processed in memory, never stored
The problem

You waste a minute every time you askChatGPT to fix your text.

Without Keystro

The copy-paste detour

≈ 60s
01

Tab to ChatGPT

3s

Leave your current app

02

Paste your text

2s

Move private context elsewhere

03

Type your prompt

10s

Think about instructions again

04

Wait for response

8s

Lose your writing rhythm

05

Copy the result

3s

Switch hands, switch context

06

Tab back to your app

3s

Find your original cursor

07

Paste & reformat

15s+

Fix spacing, bullets, tone

vs

With Keystro

The native shortcut path

< 2s
01

Select your text

0s

Stay exactly where you are writing

02

Press Ctrl+Shift+C

0.5s

Keystro reads the selection instantly

03

Done — text replaced

1.2s

Correction appears in the same app

same app, no detourin place
0 tabs
no switch
1 shortcut
same app
0 cleanup
keeps flow

Do the math

58s saved×20/day×220 days

A normal day of emails, Slack, notes, and reports.

70+ h
saved per year
≈ 2 work weeks · per user

Works inside every app you already use

Any app where you type. Keystro is there.

Gmail
Slack
Notion
Google Docs
ChatGPT
Linear
Discord
Zoom
Chrome
Gmail
Slack
Notion
Google Docs
ChatGPT
Linear
Discord
Zoom
Chrome
Real workflows

Writing isn't a feature. It's your day.

Four ways Keystro fits into the writing you already do.

1

Send a quick email without typos

You type fast. Keystro fixes.

Ctrl+Shift+C

Typo-filled email → client-ready in one shortcut

< 2 seconds
2

Summarize a long email thread

Select the whole thread, add //summarize email thread. Key points, decisions, action items.

Ctrl+Shift+A + saved prompt

Long thread → bullets, decisions, and next steps

Saves minutes per thread
3

Turn rough notes into meeting minutes

Take notes raw during the call. Add //format as meeting minutes. Structured output in seconds.

Ctrl+Shift+C + //

Rough notes → structured minutes

From raw to report-ready
4

Write like a pro on Slack, Teams, WhatsApp

Type casual and fast. Correct keeps your tone — just cleans typos and grammar. You never look sloppy again.

Ctrl+Shift+C

Casual chat → same voice, zero typos

Keeps your voice
mail.app — new message
Preview
Before

hey, could we reschdule the meeting on thursdey? i had a conflit with another client

Ctrl+Shift+C
▶
After

Hey, could we reschedule the meeting on Thursday? I had a conflict with another client.

Same shortcut, every workflow

One app. One shortcut. One visible outcome.

Each row above is a real pattern: select your text, press the chord, and the result replaces your selection — no new window, no copy-paste.

Email
clean typos
Thread
extract decisions
Notes
format minutes
Chat
keep tone
1
Select your text
2
Press the shortcut
3
Done replaced in place

No window. No copy-paste. No tab-switch.

Keyboard-native actions

One shortcut for every writing task.

Each shortcut is purpose-built for a specific need. No generic prompts. Targeted, instant, in place.

Ctrl+Shift+C

Correct

Fix grammar, spelling, and structure instantly. Add // at the end for any custom instruction.

Ctrl+Shift+E

Draft Email

Transform any draft into a polished professional email that keeps your voice.

Ctrl+Shift+A

Ask

Open a prompt on your selection and ask anything — translate, rewrite, summarize, expand, Q&A.

One shortcut. Every action.

Add // followed by any instruction after your selection. Translate, shorten, change tone, expand — the same Correct shortcut does it all.

Inline instruction demo
Preview
Your selection

Bonjour, je voudrais savoir si le projet avance bien.

//translate to English, make it more formal

Ctrl+Shift+H
▶
Result

Dear colleague, I would like to inquire about the current progress of the project.

Add // plus your instruction after the selection, then press Correct — translate, change tone, shorten, or expand without leaving the app.

Works in any language, with any instruction. Translation, tone change, shortening, expansion — all through //.

Built for people who write all day.

If your job is writing, Keystro is your unfair advantage.

Consulting & Client-facing

You write client proposals, meeting notes, and reports daily. Your reputation rides on every word.

Top shortcuts
CorrectDraft EmailAsk
Time saved
3-5 hours saved per week on emails, notes, and reports

Sales & Business Development

You send dozens of outreach messages every week across email, LinkedIn, Slack. Speed and clarity win deals.

Top shortcuts
Draft EmailCorrectAsk
Time saved
2x faster follow-ups across email, LinkedIn, and chat

Managers & Executives

You draft memos, reports, and updates. Polish matters. Sometimes English isn't your first language.

Top shortcuts
CorrectDraft EmailAsk
Time saved
Board-ready writing without leaving the current app
Security & Privacy

Your text is processed, never stored.

Zero-content-storage architecture. Your text flows through AI, returns corrected, and is immediately discarded — by design.

How your data flows

Your machine

Tokens encrypted via Windows DPAPI. No text saved locally.

Keystro Backend

Helmet headers, rate-limited, JWT auth, zero content logging.

OpenAI API

Processed in memory. Not stored. Not used for training.

Zero Data Retention

store: false on every AI call. OpenAI is contractually prevented from storing, logging, or training on your text.

No content logging

We track usage metadata only (action type, character count). Your actual text never touches our database.

Encrypted locally

Auth tokens encrypted on your machine via Windows DPAPI. Your credentials never leave your device.

What we store

Transparent by design.

  • Your text contentNowhere
  • Auth tokensYour machine · DPAPI encrypted
  • Account infoEU PostgreSQL
  • Usage metadataEU PostgreSQL
  • Personal vocabularyEU PostgreSQL

How we protect it

Defense in depth.

  • TLS 1.2+ on all traffic · HSTS · strict CORS
  • Clerk JWT auth · webhook signature verification
  • Rate limiting · DTO validation · Helmet headers
  • store: false on every OpenAI call
  • Structured logs — metadata only, never content
GDPR-readyEU hosting (Railway)OpenAI DPARight to erasureZero Data Retention

Security questions from your IT or security team? Contact us

Questions, answered.

How is this different from ChatGPT?+
ChatGPT requires tab-switching, copy-pasting, and writing a prompt every time. Keystro corrects, rewrites, or summarizes your text in place, inside the app you are already using, in under two seconds. Same AI intelligence — without the friction.
Does Keystro work on Mac?+
Not yet. Keystro is Windows 10 and 11 only today. A macOS version is on our roadmap.
Is my text safe?+
Yes. Every AI call includes store: false — OpenAI is contractually prevented from storing, logging, or training on your text. We never write your text to any database, log file, or cache. Only anonymous usage metadata (action type, character count) is recorded.
What AI model does Keystro use?+
We ship GPT-5.4 Mini as our production model, updated alongside our releases. The model handles French, English, Spanish, German, Italian, and more.
Does Keystro work offline?+
No. Keystro processes text through our secure backend, so an internet connection is required. Processing typically completes in under two seconds on a normal connection.
What languages does Keystro support?+
All major languages — French, English, Spanish, German, Italian, Portuguese, Dutch, and more. Use // after your selection to translate between any of them.
Can I cancel anytime?+
Yes. Monthly plans only, no commitment, no questions asked. If you cancel, your account and all associated data can be deleted on request.

Simple, transparent pricing.

Start free and make Keystro a reflex. Upgrade when you can't imagine working without it. Cancel anytime.

Free

Build the habit. No card required.

€0forever

Enough to make Ctrl+Shift+C a reflex

Get Started Free
  • 50 AI requests / month
  • All 3 shortcuts — Correct, Draft Email, Ask
  • Inline // instructions (translate, shorten…)
  • 5 personal prompts (My Prompts)
  • 25 Personal Vocabulary terms
  • Community support
Most Popular

Pro

For professionals who write all day.

€9.99/month

Everything you need for daily work

Start Pro

Everything in Free, plus:

  • 1,000 AI requests / month
  • Full prompt library — up to 20 prompts
  • 200 Personal Vocabulary terms
  • Profile-aware AI — matches your role & industry
  • Priority email support

Pro+

For power users who live in their inbox.

€19.99/month

Maximum volume & personalization

Go Pro+

Everything in Pro, plus:

  • 3,000 AI requests / month
  • Up to 50 personal prompts
  • 500 Personal Vocabulary terms
  • Priority support

Prices in EUR. VAT not applicable (art. 293 B CGI) — the price you see is the price you pay. Free plan needs no credit card. Cancel anytime.

Compare every feature

FeatureFreeProPro+
Usage
AI requests / month501,0003,000
Correct, Draft Email, Ask
Inline // instructions
Personalization
My Prompts library52050
Personal Vocabulary terms25200500
Profile-aware AI (role & industry)
Email signature on drafts
Privacy & security
Zero Data Retention (store: false)
No text content ever stored
Encrypted local tokens (DPAPI)
GDPR export & delete
Support
Community support
Priority email support—

Privacy isn't a paid add-on — every plan, including Free, gets the same security posture. See how we protect your text →

Stop tab-switching. Start writing at the speed of thought.

30 free requests every month, forever. No credit card.

Get Keystro for Windows

Windows 10/11 · Install in 60 seconds · Cancel anytime