uTLS

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What uTLS actually does

A fork of Go's TLS package that lets a caller choose the exact ClientHello it emits — cipher order, extensions, curves, ALPN — instead of accepting whatever the standard library composes.

What uTLS's maintenance signals mean

The liveness field here is pushed_at, read as 2026-08-02 against a field check 12 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. v1.8.2 was published 2026-08-02, 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 uTLS sits in this catalogue

uTLS is filed in section 07, network, tls & http fingerprint tooling, whose scope is this: The layer below JavaScript: TLS ClientHello and HTTP/2 fingerprinting, impersonating clients, and the passive tooling that reads them. 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: uQUIC (ACTIVE), curl-impersonate (lexiforest) (ACTIVE), curl-impersonate (lwthiker) (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.

It is published under BSD-3-Clause, alongside the rest of the BSD-3-Clause 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.

What to settle before you adopt uTLS

Almost everything else in this section stands on it, directly or by imitation, so understanding its ClientHello specification model pays off repeatedly. Browser presets age as browsers ship, so check which versions the current release fingerprints.