AI Proofreader
Privacy-first grammar and tone checker for any text field.
Standalone $2.99/mo or $29.90/yr.
Why it matters
What AI Proofreader does that nothing else does
- Benefit 1:
Checks grammar in any text field — Gmail, Notion, Slack, GitHub, comment boxes.
- Benefit 2:
Runs entirely in your browser; your draft is never sent to a third party.
- Benefit 3:
No account, no API key — install and use immediately.
- Benefit 4:
Pro adds tone analysis, custom dictionary, and writing-style stats.
Pricing
Buy AI Proofreader alone, or get the bundle
Use only this extension? Buy it standalone. Use three or more Aegis extensions? The Pro Pack pays for itself.
Standalone
AI Proofreader Pro
$2.99/mo
Or $29.90/yr — save when paid annually.
Pro tier on AI Proofreader only. Cancel anytime.
Get AI Proofreader ProBest value
Save $21/yrAegis Pro Pack
$9.99/mo
Or $99/yr — covers every Aegis extension you install.
Unlocks Pro on AI Proofreader and every other Aegis extension. New extensions included automatically.
Get the Pro PackBuilt the Aegis way
Privacy you can verify, not just claim
On-device by default
Every Aegis extension runs in your browser. No silent cloud upload, no server-side processing of your activity.
Never sold, never bundled
Aegis extensions never change ownership. Updates come from the same publisher you trusted at install.
No account required
Install and use immediately. Pro features unlock with a single sign-in to your Aegis Pro Pack.
MV3-native
Built for Chrome Manifest V3 from day one — no deprecation warnings, no broken background pages.
Why switch
AI Proofreader vs Grammarly
Grammarly charges several times more per month and uploads every keystroke to its servers. AI Proofreader runs grammar checks on-device in any text field, no upload and no account, for a lower monthly price.
| Feature | AI Proofreader | Grammarly |
|---|---|---|
| Monthly price | $2.99/mo | $12.00/mo |
| Account required | No — install and use immediately | Often yes (varies by competitor) |
| Data leaves the browser | No — on-device by default | See competitor privacy policy |
| Ownership transfer risk | Aegis never sells extensions | Varies — see ExtensionWatch in this catalog |
| Bundled with Aegis Pro Pack | Yes — $9.99/mo unlocks every extension | No bundle |
See it in action
AI Proofreader screenshots


More screenshots and the full feature walkthrough live on the AI Proofreader landing page.
Common questions
- Does my draft get uploaded to check grammar?
- No. Rule-based checks plus on-device browser AI handle suggestions inside Chrome. The text never leaves your machine. Compare to Grammarly's default behaviour of POSTing every keystroke.
- Where does it work?
- Any text field on any page — Gmail compose, Notion docs, Slack messages, GitHub PRs, comment boxes, web forms. The extension does not need a per-site adapter.
- How is the tone analysis done without a server?
- Pro tone analysis uses the on-device browser AI APIs Chrome ships with the user-side model. No tone request leaves the browser.
- How does the Aegis Pro Pack unlock AI Proofreader?
- Sign in to aegisfirma.com from any installed Aegis extension popup. The cookie-auth flow detects your active Pro Pack and unlocks Pro features instantly — no license key to copy or paste.
- Where is my AI Proofreader data stored?
- AI Proofreader stores everything in chrome.storage on your device. Your subscription record lives in our payment provider's account; we do not aggregate browsing or activity data.
- Can I cancel AI Proofreader Pro anytime?
- Yes — billing stops at the end of the current period. Pro features remain active until the period ends, then drop back to the free tier.
- Why should I trust an extension I just heard of?
- Aegis extensions never change ownership and never sell user data. We publish security audit results and ship MV3-native code so Chrome itself enforces the permissions we claim.
Try AI Proofreader free, upgrade when ready
Free tier covers the basics. Pro Pack at $9.99/mo unlocks every Aegis extension at once.