AI to undo your AI writing.
3 free emails. No credit card.
Kill the emdash
Emdashes scream AI. Sinceerly kills them.
No more "not just…"
Undo the annoying phrases that AI uses over and over.
Add some typos
Humans make mistkaes.
Product
Three levels.
One slider.
Original email AI slop
I wanted to reach out to express my interest in connecting regarding potential synergies between our organizations. I believe there is significant value in exploring how we might collaborate moving forward. Please let me know if you would be available for a brief call at your earliest convenience.
How it works
Open Gmail.
Click the icon.
01
Write your email
Draft normally. Use AI to write the first version, or write it yourself. Doesn't matter.
02
Click the icon
The Sinceerly panel appears inside your compose window. Hit humanize.
03
Review & replace
Yellow highlights show every change. Approve and replace with one click.
Pricing
Simple. No surprises.
Free
$0
forever
- 3 free email rewrites
- All three intensity levels
- Works inside Gmail compose
- Yellow change highlights
Pro most popular
$4.99
per month
- Unlimited rewrites
- All three intensity levels
- All 3 levels run in parallel, switching is instant
- Cached results so reopening is instant
Bring Your Own API Key (BYOK) Have an Anthropic API key? Use it directly in the extension settings. Your email text and API key aren't stored by us. Pay only for what you use.
Built to keep your emails yours.
- ✓All requests sent over HTTPS. Emails and keys aren't retained.
- ✓We don't log or retain your email content.
- ✓BYOK API keys stay in your browser only.
- ✓We only see the text you choose to humanize.
