The code lands
A site emails you a one-time code. It arrives in Gmail like always — a tab quietly open in the background.
OTP autofill · for every Chromium browser
The verification code,
already typed.
Otto reads the one-time code from your inbox and offers it on the exact page it was meant for — one click, no copy-paste, no app-switching. Like Safari's autofill, finally on Chrome, Arc, Edge & Brave.
- 100% on-device
- No account
- Open source
01 — the flow
Three seconds, zero friction.
Otto reads it
Otto grabs the code and the service it's for — ignoring dates, order numbers and other noise.
It fills the right page
A chip appears only on the login it belongs to. One click and all six boxes fill themselves.
02 — why otto
Built to disappear
into your day.
It knows where the code belongs
Otto reads which service sent the code and only offers it on that site. Jump to another tab and the suggestion won't follow you where it doesn't belong.
SuperDM → 1 5 7 0 0 4
Used once, gone
Fill a code and Otto retires it. A freshly sent code — even the same digits — counts as new and active.
Fills the tricky fields
Single inputs, six separate digit boxes, stubborn React & Vue forms — Otto fires the right events so it sticks.
Every Chromium browser
Chrome, Arc, Edge, Brave. The seamless feel Mac users only had in Safari — now everywhere.
No account, ever
Install and go. No sign-up, no onboarding. It works the moment it's added.
03 — pricing
Priced the way it should be.
No tiers, no trials, no catch. Otto is free and open source — support it only if it earns a place in your day.
The Extension
Free/forever
- Source-aware autofill
- Split-box & React forms
- 100% on-device
- No account required
The Code
$0/MIT
- Every line auditable
- Fork & self-host freely
- No servers, no analytics
- Community-driven roadmap
Support
Pay/what you want
- Fund maintenance
- Sponsor new providers
- Get a warm feeling
- Cancel anytime (it's a tip)
04 — privacy
Nothing leaves
your browser.
Otto has no servers, no analytics, and no backend to leak. The code is read from your own open Gmail tab and stays on your machine — full stop.
Read the source →- ✓ No data ever sent to a server
- ✓ No tracking, no analytics, no ads
- ✓ No account or email required
- ✓ Reads only your open Gmail tab
- ✓ Codes expire from memory in minutes
- ✓ Open source & independently auditable
05 — get otto
Add it in about a minute.
Otto is in early release — load it unpacked today, or grab the Web Store build soon.
- 01Download or clone the repo
- 02Open
chrome://extensions→ enable Developer mode - 03“Load unpacked” → pick the folder
- 04Keep a Gmail tab open. Done.
06 — questions
Good things to know.
How does it only show on the right page?
Otto reads which service the code is for — from the sender and the wording of the email (“your code to sign in to SuperDM”). It then offers the code only on a page that matches. Switch tabs and the chip stays behind where it belongs.
Does my Gmail have to be open?
It needs to be open as a background tab — you never have to look at it. You stay on the login page while Otto watches your inbox quietly behind it.
Is my email safe? Where does the code go?
Nowhere but your own browser. Otto reads the code from your open Gmail tab and keeps it locally for a few minutes. No servers, nothing uploaded — and it's open source, so you can verify exactly that.
What if the same code is sent again?
Once you use a code, Otto retires it. If the site re-sends — even with identical digits — Otto stamps the new arrival and treats it as a fresh, active code you can use again.
Which browsers work?
Any Chromium-based browser: Chrome, Arc, Edge, and Brave. If it runs Chrome extensions, it runs Otto.
What about Outlook, iCloud or Proton?
Gmail is supported today. Other providers are on the roadmap — the architecture makes each one a small add-on. Want one next? Open an issue on GitHub.