ThumbmarkJS

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What ThumbmarkJS actually does

An independent fingerprinting library that publishes a component-by-component breakdown of what it collects and how each part contributes to the resulting identifier.

What ThumbmarkJS's maintenance signals mean

The liveness field here is pushed_at, read as 2026-07-17 against a field check 28 days later. That is inside 90 days, and 90 days is where the second edition of the rubric put ACTIVE after moving it down from the first edition's 180.

The reason for the move is worth stating, because it is the kind of threshold that looks arbitrary until you know what it is measuring against: detection changes on a shorter cycle than half a year, so a six-month-old evasion is not a current one. What a recent push does not tell you is what was in it. A commit landing on a branch is not a release, not a fix, and not a test — it is evidence that somebody is still there.

The release field is a second and different signal. v1.10.1 was published 2026-07-17, and the gap between that date and the push date above is the interval in which work exists but has not been cut into anything you can pin a dependency to. A project that pushes constantly and tags rarely and a project that does the reverse look very different to anyone trying to depend on either.

Where ThumbmarkJS sits in this catalogue

ThumbmarkJS is filed in section 06, fingerprinting libraries, whose scope is this: The collectors themselves — the code that reads a browser. Read these to know what is being asked of you. 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Filed beside it in the same section: fingerprintjs2 (Valve) (WITHDRAWN), BotD (ACTIVE), ClientJS (DEAD). 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.

It is published under MIT, alongside the rest of the MIT entries in this register, and it sits with everything else currently marked ACTIVE. Read those two facets together: a permissively licensed project that stopped shipping is not a safer dependency than a copyleft one that did not, and a filter on one axis alone will tell you the wrong thing.

Substitutes for the same job, with no claim that either is better: ClientJS, FingerprintJS. The alternative relation is symmetric and carries no ranking, because this register publishes no ranking of any kind. The full ThumbmarkJS comparison table sets all of them side by side on licence, push date, release cadence and state.

What to settle before you adopt ThumbmarkJS

The published breakdown is the reason to prefer it as a teaching reference over a library that hands you an opaque hash. Verify the component list against the version you install, since components are added between releases.