Whole Antidetect Catalog Donut Browser

Catalogue · Section 03 · Entry

FP-Monitor (fpmon)

ACTIVE

FP-Monitor (fpmon) is a live page catalogued in section 03 of this register. Academic tool that measures how much fingerprinting a site is actually doing to you. At the last field check its address answered, which is the whole of what ACTIVE means for an entry with no repository behind it.

https://github.com/fpmon/fingerprinting-monitor

Repository linked in place of the listed address — the register's linking policy.


The fields this state was derived from

FieldValue at this printing
http_status 200
fetched_at 2026-08-14T09:12:00Z
endpoint HEAD https://fpmon.github.io/fingerprinting-monitor/
rubric_edition 2nd, in force since 2026-08-14

This entry has no repository, so there is no API field a browser can re-read across origins. Its state comes from the register's own link check, printed above with the instant it was made.

Why it reads ACTIVE

No repository. The link check returned 200 at 2026-08-14T09:12:00Z, and 200–399 is ACTIVE for a non-repository entry.

Shipping. Safe to build on today.

Under the superseded first edition

UNSTATED ACTIVE
No repository. The first edition had no link liveness sweep and therefore no field to read here.

The rubric in force · The superseded first edition · Errata leaf


What FP-Monitor (fpmon) actually does

An academic instrument pointed the other way: instead of showing what your browser reveals, it measures how much fingerprinting activity a given site is performing on you, and of what kind.

What can and cannot be measured about FP-Monitor (fpmon)

This entry has no repository, so none of the usual repository fields exist for it — no push date, no release tag, no archive flag, no licence identifier. Its state comes from one measurement only: the register requested the address and recorded what came back. Anything in the range 200 to 399 makes a non-repository entry ACTIVE, and that clause is the one the first edition of the rubric did not have at all, which is why live page entries carried no state under it.

Read that for exactly what it is. It says the thing is reachable. It does not say the page still works correctly, because no HTTP status can carry that. Where a stronger signal exists — a repository, a version, a dated revision — this register prefers it, and where one does not, it prints the weaker signal and names it as weak rather than dressing it up.

Where FP-Monitor (fpmon) sits in this catalogue

FP-Monitor (fpmon) is filed in section 03, detection test pages & fingerprint scanners, whose scope is this: Pages you point a browser at to see what it gives away. This section is where a link register earns its keep: test pages rot faster than repositories. An entry sits in exactly one section here. Where a project could defensibly go in two, it is placed where a reader would look for it first rather than where it fits most tidily, and that is an editorial decision rather than a measured one.

Filed beside it in the same section: Scrapfly fingerprint API (ACTIVE), check.ja3.zone (ACTIVE), Brotector (NRND). Comparing an entry against its own section-mates is more informative than comparing it against the catalogue as a whole, because everything in a section is answering roughly the same question and the differences left over are the ones that matter.

There is no licence field, because there is no source to licence — this is a live page rather than a code repository. It is grouped instead with every other entry the rubric marks ACTIVE, which is the axis that actually distinguishes entries of this kind from one another.

What to settle before you adopt FP-Monitor (fpmon)

It answers a different question from the rest of this section, which is what makes it worth having. Its classification reflects the surfaces the authors instrumented, so absent activity means absent from that list.


Questions readers ask about FP-Monitor (fpmon)

Answered from this entry's own fields, at the field check printed above and at no other instant.

Is FP-Monitor (fpmon) still maintained?

FP-Monitor (fpmon) has no repository, so this register cannot answer that from a commit history. What it can do is request the address and record the result, which is what produced ACTIVE. Shipping. Safe to build on today.

What else in this registry does the job FP-Monitor (fpmon) does?

No substitution edge is declared for this entry, which means nobody has stated one rather than that none exists. The nearest comparison available is the rest of section 03, where everything is answering roughly the same question on the same printed fields.

What licence is FP-Monitor (fpmon) under?

The question does not apply — FP-Monitor (fpmon) is a live page rather than source code, so this register records the licence field as not applicable rather than inventing one. Terms of use, where they exist, are the publisher's to state at the address above.

Why did the state recorded for FP-Monitor (fpmon) change?

Because the rules changed, not because the world did. The same field data reads UNSTATED under the superseded first edition and ACTIVE under the edition in force. Both derivations are printed on this page, and the entry appears on this printing's errata leaf with the superseded value struck rather than deleted.


A test page tells you that something is inconsistent. It does not tell you which layer produced the inconsistency, and it will not fix it. Donut Browser is an open-source anti-detect browser under AGPL-3.0 that addresses the layer most of these pages are reading: engine-level fingerprint overrides through CDP rather than injected script, with a pre-launch gate that refuses to start a profile when the proxy's exit geography contradicts the profile's own fingerprint.

Download Donut Browser

curl -fsSL https://donutbrowser.com/install.sh | sh

macOS (DMG, Homebrew cask donut), Windows (installer and portable), Linux (deb, rpm, AppImage, with APT and RPM repositories at repo.donutbrowser.com), and a Nix flake. Desktop only — there is no mobile build target. Ten shipped languages. Source, AGPL-3.0 · its own entry, judged by the same rubric · the keepers' disclosure.