HeadlessChrome

Chickenus noheadus

Vagantes, the strays. Headless browser.

A joke about the drawing A chrome-plated chicken, minus the head. Runs every script it finds.

The line above plays on the name. It says nothing about how the bot behaves: everything below is read from the request log, for today and the 29 days before it, by UTC date.

Alignment

Insufficient data. A judgement needs at least 200 requests and 5 sessions in the trailing 30 days. This one would rest on all its sessions: 4 requests in 1 session over the trailing 30 days.

How the score is worked out, and the count behind every input, is on the Census page.

Who runs it, and how that is checked

Who runs it: Whoever is driving it
A user-agent string it sends: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/131.0.0.0 Safari/537.36
What it says it is for: HeadlessChrome is the Chrome browser running without a window, driven by automation. It renders pages and runs scripts as a person’s browser would.

Everything above is a claim: the operator’s own account where it has published one, and a third party’s where it has not. This site has not tested it. What the bot has done is in the sections below, read from the request log.

No operator. Anyone can run it, so there is no identity for Customs to check, and its sessions are filed as undeclared.

The name it is matched on

A request is filed under this species when its user-agent string contains the product name HeadlessChrome as a whole word, in any mix of capitals. Where a string holds more than one product name, the longest wins, and a named bot wins over a library it is built on.

How to address this bot in robots.txt

A group in robots.txt addresses this bot by the line:

User-agent: HeadlessChrome

An example group. The path is a placeholder.

User-agent: HeadlessChrome
Disallow: /a-path/
Allow: /a-path/one-page

This is reference, not advice. Systema Machinae is not a bot-blocking product.

This site’s own robots.txt does not name it. The group for every bot applies.

Landings

1 landing in the trailing 30 days. A landing is the first request of a session.

By day

The same figures as a table

Landings on each of the last 30 days, UTC
Day	Undeclared
10 Sep	0
11 Sep	0
12 Sep	0
13 Sep	0
14 Sep	0
15 Sep	0
16 Sep	0
17 Sep	0
18 Sep	0
19 Sep	0
20 Sep	0
21 Sep	0
22 Sep	0
23 Sep	0
24 Sep	0
25 Sep	0
26 Sep	0
27 Sep	0
28 Sep	0
29 Sep	0
30 Sep	0
1 Oct	0
2 Oct	0
3 Oct	0
4 Oct	0
5 Oct	0
6 Oct	0
7 Oct	0
8 Oct	0
9 Oct	1

By hour of the day, UTC

The same figures as a table

Landings in each hour of the UTC day, over the last 30 days
Hour	Undeclared
00:00	1
01:00	0
02:00	0
03:00	0
04:00	0
05:00	0
06:00	0
07:00	0
08:00	0
09:00	0
10:00	0
11:00	0
12:00	0
13:00	0
14:00	0
15:00	0
16:00	0
17:00	0
18:00	0
19:00	0
20:00	0
21:00	0
22:00	0
23:00	0

Busiest hour: 00:00 UTC, with 1 landing.

What it asks for

Part of the site	Undeclared requests
Addresses the site does not have	4

Parts of the site, from a fixed list. The address of a request is never shown.

Its record with each rule

Trailing 30 days	Undeclared
Sessions	1
Requests	4
Sessions that asked for anything besides robots.txt	1
read robots.txt first	0
had read it in the 24 hours before	0
read it only afterwards	0
did not read it	1
Sessions that entered the Pitfall	0
having read robots.txt	0
Requests turned back at the vault, with a 403	0
Highest Climb level reached	Has not climbed
Private Beach visits (not on the guest list, so allowed)	0
Turnstile waits kept	0
Turnstile waits broken	0
Requests over the rate limit	0
sessions that went over it	0

These are counts, not a verdict. A session is judged on what it did inside the 30 days.

Customs

Customs does not check it. It names no operator, so there is no claim to test: 1 session filed as undeclared in the trailing 30 days.

Where it comes from

Undeclared sessions, the busiest 1
Network owner	Country	Sessions	Requests
Hurricane Electric LLC	United States	1	4

Network owner and country only. An address is never shown.