Catalogue · Section 03 · Entry
Are You Headless
DEAD
Are You Headless is a live page catalogued in section 03 of this register. Antoine Vastel's headless-detection page — cited in dozens of tutorials and, at this field check, returning 502. It reads DEAD at the last field check, and it is still listed as live by registries that do not check. The status and the instant it was read at are both printed below.
https://arh.antoinevastel.com/bots/areyouheadless
The fields this state was derived from
| Field | Value at this printing |
|---|---|
| http_status | 502 |
| fetched_at | 2026-08-14T09:12:00Z |
| endpoint | HEAD https://arh.antoinevastel.com/bots/areyouheadless |
| 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 DEAD
The link check returned 502 at 2026-08-14T09:12:00Z. DEAD is tested first.
Unreachable, or untouched past the outer threshold.
Under the superseded first edition
UNSTATED
DEAD
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The rubric in force · The superseded first edition · Errata leaf
Curator's annotation
Listed precisely because other registries still list it without checking. A dead entry that is marked dead is more useful than a live entry nobody verified. — ED.
What Are You Headless actually does
A headless-detection page from a researcher who also publishes the peer-reviewed version of the same work, which is why it is cited in a great many tutorials.
What can and cannot be measured about Are You Headless
There is no repository behind this entry, so the only liveness signal that exists for it is whether its address answers. At the field check it returned 502, and the rubric tests that condition before it tests anything else — an address that cannot be reached cannot be rescued by any other field.
A dead live page is worth keeping in a register rather than deleting, because deletion loses the finding. What you can do with this row is check the address yourself: it is printed above, the status is printed beside it, and the instant both were read is printed with them. If it answers for you, the register is wrong and the correction is an errata entry against a named edition.
Where Are You Headless sits in this catalogue
Are You Headless 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: FP-Monitor (fpmon) (ACTIVE), Brotector (NRND), deviceinfo.me (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.
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 DEAD, which is the axis that actually distinguishes entries of this kind from one another.
Substitutes for the same job, with no claim that either is better: bot.sannysoft, Rebrowser bot detector. The alternative relation is symmetric and carries no ranking, because this register publishes no ranking of any kind. The full Are You Headless comparison table sets all of them side by side on licence, push date, release cadence and state.
What to settle before you adopt Are You Headless
At this field check it did not return successfully, and it is still recommended widely by lists that do not check. That gap between what is recommended and what responds is the reason the link sweep exists.
See also
| Relation | Entry | State | Last push |
|---|---|---|---|
| alternative to | bot.sannysoft | ACTIVE | — |
| alternative to | Rebrowser bot detector | ACTIVE | — |
Questions readers ask about Are You Headless
Answered from this entry's own fields, at the field check printed above and at no other instant.
Is Are You Headless still maintained?
Are You Headless 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 DEAD. Unreachable, or untouched past the outer threshold.
What are the alternatives to Are You Headless?
bot.sannysoft, Rebrowser bot detector are recorded as substitutes for the same job. The relation carries no ranking — this register publishes none — so read them side by side on the comparison table, which prints licence, last push, release cadence and state for each.
What licence is Are You Headless under?
The question does not apply — Are You Headless 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 Are You Headless change?
Because the rules changed, not because the world did. The same field data reads UNSTATED under the superseded first edition and DEAD 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.
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.