What a browser fingerprint is, and how LoginDeck builds one
A fingerprint is the set of traits a site reads to tell one computer from another. LoginDeck generates one whole machine per profile.
On this page
Every browser answers dozens of small questions without being asked: which operating system it runs on, how big the screen is, which graphics card draws the page, which fonts are installed, how many CPU threads there are, what the clock says. Together those answers are a fingerprint, and a site can use them to recognise the same computer across accounts even when the cookies are different.
A LoginDeck profile carries its own fingerprint, so each profile looks like a separate computer rather than a second window of yours.
🧬 What a site can read#
- Identity: the user agent,
navigator.platform, the client hints (platform, OS version, full browser version), the language list, the browser version. - Hardware: CPU threads, device memory, the WebGL vendor and renderer strings, the WebGPU adapter, screen and window size, the installed font list, the number of cameras, microphones and speakers.
- Location: the exit IP, the timezone, and whether the clock agrees with the address.
- Readbacks: canvas, WebGL images, audio and client-rect measurements — values that come out slightly differently on different hardware.
- Automation tells:
navigator.webdriver, WebRTC candidates, the plugin list,window.chrome.
You can see all of it, for one profile, with the built-in fingerprint check.
🏗️ How LoginDeck generates one#
A fingerprint is not a bag of random values. Detectors rarely ask "is this canvas hash on a blocklist" — they ask whether the user agent, font list, GPU string and screen size could all have come from the same computer. Randomising each field on its own produces a Windows user agent with a Mac graphics card and Linux fonts, which stands out more than not changing anything.
So LoginDeck picks a machine first, then reads every trait off that one choice:
| Trait | Where it comes from |
|---|---|
| User agent, platform, client hints | The Operating system you picked, plus the profile's Browser version |
| Graphics card | A card that really ships with that operating system. The WebGL strings and the WebGPU adapter name the same chip |
| Screen size | A resolution that is actually common on that platform, not a random number |
| CPU threads and memory | Drawn as a matching pair (for example 8 threads with 16 GB) |
| Fonts | The base font set that ships with that operating system |
| Cameras, mics, speakers | One of each by default, because a browser reporting none of anything reads as headless |
| Language list | A full list, for example en-CA, en — a real browser never reports only the region tag |
| Timezone | Looked up through the proxy, so the clock matches the address |
The whole machine comes from one random seed, which is why it is the same every time the profile opens.
You don't have to choose any of this
Create a profile, pick an operating system if you care, and leave the rest alone. The generated machine is already internally consistent. The Advanced tab is there for the rare case where one site is giving you trouble.
🔁 One seed, one machine#
- Click New fingerprint on the editor's Overview tab to give the profile a different machine. The toast says "New machine generated".
- Changing Operating system or Language rebuilds the machine from the same seed, so it stays as close as it can while staying consistent — a Windows machine becomes the Mac version of itself, not an unrelated computer.
- Profiles created in a batch never share a fingerprint. Each one gets its own machine.
🖥️ The computer it runs on still matters#
Some things a page reads come from your own machine and cannot be rewritten by any browser: the display's scale factor, whether there is a touchscreen, and which font files really exist. A profile that claimed a 1536×864 screen on a laptop running at 200% scaling was describing a panel that does not exist.
So at launch, LoginDeck fits Windows profiles to the computer they are opening on: the screen size is moved to one that is real at this display's scale, the Windows 10 / Windows 11 claim follows the actual host, and the font list is narrowed to fonts this machine really has. The saved profile is not changed — the same profile on another computer fits itself there, exactly as a real Chrome would show that machine's screen.
🦊 Firefox profiles#
A profile set to the Firefox engine runs on LoginDeck's bundled Firefox (Camoufox), which generates its own consistent Firefox values. LoginDeck constrains the parts the profile owns — operating system, screen, language, timezone, fonts and the GPU strings — and lets the engine fill in the rest. A Firefox profile reports no deviceMemory and no client hints, which is correct for Firefox. See Chrome or Firefox.
ℹ️ Good to know#
- A phone profile (Operating system → Android) is a complete handset: screen, pixel ratio, touch points, model hint and a mobile GPU, all from the phone you pick. See Android (mobile) profiles.
- The user agent is built from the operating system and browser version; you cannot type your own. A
--user-agentflag in Launch arguments is dropped. - Memory is reported as at most 8 GB, because that is the most a real Chrome ever reports. A 16 GB profile still reads 8.
- A fingerprint is only half the job. The address you come from, and how the account behaves, matter at least as much: see What no antidetect browser can change and Good habits that keep accounts safe.