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DEVICE IDENTITY

Recognize the device, not the cookie. Through cleared storage, private windows and new IP addresses.

LR Defender derives a device ID on its servers from 90+ browser, hardware and runtime signals. The ID comes from signals, not stored values, so wiping cookies and storage does not reset it. It is scoped to your account, so it means nothing anywhere else.

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Devices / dv_4a1c…Example data
dv_4a1c…
Visits by week

Visits

38 since May

First seen

May 12, 2026

Scope

This account only

  1. Sep 25, 14:02stable signals198.51.100.23allow
  2. Sep 24, 09:41stable signals after storage wipe198.51.100.23allow
  3. Sep 19, 18:15stable signals203.0.113.51allow
  4. Sep 11, 08:03stable signals198.51.100.23allow
  • Derived on our servers
  • Scoped to your account
  • Survives a storage wipe
  • Confirmed from your server

QUESTIONS THIS ANSWERS

  • Is this the device we saw last week?

    Every result carries a match type, a confidence value, the visit count and the first-seen date.

  • Did they just clear their cookies?

    The ID does not depend on them, so a wipe changes nothing.

  • Is the hardware what it claims to be?

    We read the GPU through independent paths. A renderer string that disagrees with itself is flagged.

  • Did they switch browsers?

    Chrome and Edge share an engine, and the device carries across them. Other engines are in evaluation.

How it works

Derived where it cannot be edited.

The SDK collects and our servers decide. The raw signals become an ID on our side, so the browser never holds the logic that makes it.

Browser SDK

Collects 90+ browser, hardware and runtime signals.

Our servers

Turn the signals into a device ID.

Your account

Gets an ID that means nothing anywhere else.

How it matched, stated.

Each result carries a match type and a confidence value. Confidence says how close the match was. It is a heuristic, not a probability, and we do not present it as one.

Devices / dv_4a1c… / Sep 24, 09:41Example data
Match type
stable signals after storage wipe
Confidence
0.95How close the match was. A heuristic, not a probability.
Visit count
38
First seen
May 12, 2026

Spoofed hardware, caught.

We read the GPU through independent paths, including WebGL, a worker's offscreen canvas and WebGPU, and compare the model each one reports. A laptop GPU claiming to be a flagship card disagrees with itself.

Devices / dv_4a1c… / GPUExample data

Claimed renderer: NVIDIA GeForce RTX 4090

  • WebGL, main threadNVIDIA GeForce RTX 4090matches the claim
  • Offscreen canvas in a workerIntel Iris Xe Graphicsdisagrees
  • WebGPU adapterIntel, integrateddisagrees
The read paths disagree: GPU anomalyinference

Across one engine family.

Chrome and Edge share an engine, and a device carries across them. Matching across engines, such as Chrome to Firefox, is in evaluation and off by default.

One laptop, three browsersExample data
  • Chrome 131 on WindowsChromiumdv_4a1c…
  • Edge 131 on WindowsChromiumdv_4a1c…
  • Firefox 132 on WindowsGeckoMatching across enginesOff by default

Live demo

Device identity / wipe testLive, this browser

API

Your server fetches each verdict with its API key, so the verdict you act on comes from our server, not from the browser.

One script tag and two calls from your server.

Browser SDK v1.2.6

Read the quick start
Read the server API docs
Your server / verdict for this visitExample data
Device ID
dv_4a1c…The device ID, derived on our servers from hardware and runtime signals and scoped to your account.
Match type
stable signalsHow this visit was matched to the device.
Confidence
0.97How closely this visit matched a known device, from 0 to 1. A heuristic, not a probability.
Visit count
38Visits from this device to your account so far.
First seen
May 12, 2026When your account first saw this device.
Recommended action
allowThe action this identification recommends to your server.

Spec

Signals collected
90+ browser, hardware and runtime signals
Where the ID is derived
On our servers
Scope
Per customer account
Depends on cookies or storage
No
Private windows
Same device ID
Across browsers
Within an engine family, such as Chrome and Edge
Across engines
In evaluation, off by default
GPU spoof check
Compares the GPU model across independent read paths
Server lookup window
24 hours after identification
SDK
Browser SDK 1.2.6, one script tag from our script host

Limits

FAQ

No. The ID is derived from signals on our servers. Nothing about it depends on what the browser stores.

Yes. A private window in the same browser gives the same device ID.

No. The IP address is not part of the device ID. It feeds the network checks instead.

Two people on one computer share it, because it identifies the device. Identical machines can also look alike; see the limits above.

Not as an account key yet. You can send one with each identification, but one sent from the browser is never trusted to name an account. Account keys are part of account trust, in early access.

Recognize your returning devices.

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