Product · Signup Guard
Know when a new login is someone you already know.
Signup Guard links each new signup to the device and the emails behind it, and answers while the person is still logging in.
Matches the device
Behind a VPN, the browser's own traits can still match. When they don't, Darkmeter falls back to look-alike emails and behaviour.
Weighs the evidence
Device, email, network and timing are weighed together. No single signal decides.
Answers at login
One check returns allow, limit, verify or block, with the reasons behind it.
How accounts get linked
Why a new login can look like someone you know.
Darkmeter weighs several signals together. Switch one off to see what the rest can still tell you, as when a VPN or a new browser hides part of the picture.
Account you know
ava.k92@mail.example
Pune · signed up 3 weeks ago
Chrome on Windows
What Darkmeter compares
New login
ava.k93@mail.example
Frankfurt · VPN · signed up just now
Chrome on Windows, cleared
Likely the same person
High
Treat as one person: limit or cool down.
Illustrative weights. Real ones are tuned with design partners.
At login
Answers before the credits are given.
Your backend sends the email, the device token and the IP address. Darkmeter answers while the person is still logging in, so the new account gets the right grant from the start.
- One call at signup or login
- A verdict with reasons
- You decide what each verdict does
const verdict = await dm.check({
email,
deviceToken,
ip,
});
// { decision: "limit",
// reason: "device_linked_accounts" }Preview of the planned API. Names may change.
Questions
Build Darkmeter with us.
We are working with a small group of AI teams. Tell us about your free tier and what it costs you.