By Eric L.
09/08/2026 · 7 MIN READ

A browser fingerprint is a set of dozens of characteristics of your browser and device that a website can collect without cookies and without your IP address, and combine into a nearly unique identifier: screen resolution, time zone, language, installed fonts, how your graphics card renders a test image, how your audio stack processes a signal, your extensions, your OS version.

Each trait alone is ordinary; together they single you out among millions. That's why a site "recognizes" you after you switched IP with a VPN and cleared cookies: the address changed, the device didn't.

THREE INDEPENDENT LAYERSFIG. 01
IP address    VPN changes it       ✓
cookies       you can clear them   ✓
fingerprint   nothing changes it   ✗
    └─ that is why sites still know you

What goes into a browser fingerprint

Roughly in order of how much each one distinguishes you:

  • Canvas and WebGL. The site has your browser quietly draw an image or a 3D scene; different GPUs, drivers and systems produce slightly different output, and a hash of it is a stable, unique identifier.
  • Fonts. Which fonts are installed, inferred by measuring text widths. A machine with office and design software has a rare combination.
  • Audio. The AudioContext API processes a signal; the result depends on hardware.
  • Screen and window: resolution, color depth, pixel ratio, window size.
  • Language, time zone, OS, browser version. A time zone that doesn't match the IP is itself a notable combination.
  • Extensions: an ad blocker changes the page structure and reveals itself.
  • Hardware: CPU cores, memory, touch points, battery API.
HOW A HIDDEN DRAWING BECOMES AN IDSite scriptdraw this, out of sightYour GPUrenders the imageTiny differencesGPU, driver, systemA hash of itstable, unique IDNext visitnew IP, no cookiessame browser, same GPU, same drawingSame hashvisits linked
The drawing never appears on screen, but its hash follows you through a new IP and a cookie wipe.

None of this is related to your IP. That single fact drives every conclusion below.

WHAT GOES INTO A FINGERPRINTFIG. 02
screen size and color depth
installed fonts
operating system and browser build
timezone and language
how your GPU draws a test image
   └─ each is common, the set is not

Why a VPN doesn't hide your browser fingerprint

A VPN works at the network layer: the site sees the server's address instead of yours. The fingerprint is produced at the application layer: the browser itself reports these traits. The site sees "a new IP, but the same fingerprint as yesterday's visitor" and links the visits. This isn't a flaw in the VPN; it's a division of labor. The VPN handles "where you come from," the fingerprint handles "which device this is." What the VPN does cover is in what can my ISP see.

WHY A TUNNEL DOES NOT HELPFIG. 03
your address    the tunnel changes
your timezone   the browser sends
your fonts      the browser sends
your GPU quirks the browser sends
   └─ all of it rides inside an
      ordinary request, on top

How to check your browser fingerprint

Our tool. The Privacy Checker lists what your browser reveals without looking at the IP, and which traits make you stand out.

Third-party tests. EFF's Cover Your Tracks tells you how unique you are among recent visitors; AmIUnique and BrowserLeaks show the value of each trait. Try more than one; their sample sets differ.

A comparison. Test in normal mode, in a private window, and with the VPN on. If the fingerprint hash is identical in all three, you have seen the problem: private mode and VPN don't affect it.

WHAT ACTUALLY REDUCES ITFIG. 04
a browser like everyone else's  [########]
script blocking                 [######..]
default window size             [####....]
common, boring fonts            [###.....]
a new IP                        [#.......]
The only bar a VPN moves is the shortest one here: looking ordinary does more than a new address ever will.

How to reduce browser fingerprinting

Two approaches: look like everyone else, or look different every time.

TWO WAYS TO RESIST: BLEND IN OR KEEP CHANGING● LOOK LIKE EVERYONE ELSEsamesamesamesamesamesameyousamesamesamesamesameevery user reports the same valuesTor Browser, Firefox resistFingerprinting,Safari's simplified configuration● LOOK DIFFERENT EVERY TIMEYouSite A seesprint 1Site B seesprint 2Site C seesprint 3random noise on every siteBrave: noise in canvas and audio
Either blend into a crowd of identical browsers or show every site a different face.
  1. A mainstream configuration. Current Chrome or Safari, default window size, system and browser language matching, few extensions. The more ordinary, the safer, which runs against intuition.
  2. A browser that resists fingerprinting. Firefox with strict tracking protection and privacy.resistFingerprinting returns uniform values for canvas, time zone and fonts; Brave adds random noise to canvas and audio so each site sees a different fingerprint; Safari reports a simplified configuration to all sites.
  3. Tor Browser: every user looks the same. The most thorough option, at the cost of speed and compatibility.
  4. Separate identities. For anything that should stay anonymous, use a separate browser or profile with no logins to personal accounts. A unique fingerprint is useless if it isn't tied to a name.
  5. Fewer permissions. Location, camera, notifications, Bluetooth: each grant is a new trait.
  6. Don't overdo it. Disabling JavaScript or faking a rare user agent makes you more unique, not less. The goal is to disappear into the crowd.
THE PARADOX OF RARE SETTINGSFIG. 05
a browser like everyone else's
                      unremarkable
a rare browser, many extensions,
odd fonts             unique
   └─ trying to hide can make you
      easier to spot

IP, cookies, fingerprint: three independent layers

Provided byChanged by a VPNReset by
IP addressthe networkyesanother network or a VPN
Cookiesthe site, stored in your browsernoclearing data, private mode
Fingerprintthe browser itselfnoa different configuration, a resistant browser

Sites use all three: if the IP changed, they check cookies; if cookies are gone, they check the fingerprint. Handling one layer alone does little.

THREE INDEPENDENT LAYERSFIG. 06
address      changed by a tunnel
cookies      cleared in the browser
fingerprint  changed by neither
   └─ closing one does nothing
      for the other two

A fingerprint is easier to shrink parameter by parameter than all at once.

Prompt for an AI
Help me make my browser less unique.

Browser: (which, version). System: (which).
Extensions: (list all of them).
Screen resolution: (which).
What a fingerprint test reported: (paste the
conclusions).

For each parameter, say whether it makes me
stand out, whether I can change it, and what
convenience I lose.
Sort by return on effort.
If a parameter cannot be changed, say so plainly
instead of proposing workarounds that make the
browser even rarer.

When browser fingerprinting matters

For everyday browsing, it isn't a reason to panic: fingerprints are mostly used by ad networks for cross-site tracking, and the effect is which ads you see. Take it seriously when two accounts must not be linked, when you use a shared or work computer for private matters, or when research needs anonymity. Then "VPN + resistant browser + separate identity" work together. What your IP alone reveals is in what can someone do with my IP address.

WHEN A FINGERPRINT IS WORTH THE EFFORTEveryday browsingAd networks trackacross sitesEffectwhich ads you seeTAKE IT SERIOUSLY WHENTwo accounts must not be linkedShared or work computerResearch needs anonymityUSE ALL THREE TOGETHERVPNResistant browserSeparate identity
For most browsing it only decides which ads you see; when it really matters, one tool alone is not enough.

404 VPN covers the network layer: a VLESS tunnel in its apps or a WireGuard config for Istanbul and Marseille, DNS inside the tunnel, and a kill switch in the Android app. The browser layer is yours; the Privacy Checker and What Is My IP are there to check against. Get started here.

There's one more thing you hand over yourself, and it isn't the browser: a photo straight from your camera carries the coordinates of where it was taken. What's inside and how to strip it is in photo metadata: what your photos reveal.