window.chrome.* helpers are native (not JS stubs)
chrome.csi and chrome.loadTimes are either native functions or absent — never JS-defined stubs.
What a detector infers
Where the previous check asks whether window.chrome exists, this one asks whether its members are genuine. It walks chrome.csi and chrome.loadTimes and, for each that is a function, stringifies it via Function.prototype.toString; a real built-in returns a body containing { [native code] }, whereas a JavaScript replacement returns its own source text. Any that stringify as JS are collected and fail the check.
This is the mechanism that catches shimming libraries: they add these members to satisfy naive existence checks, but a function defined in JavaScript cannot stringify as native, so the very act of filling the gap creates a more specific artifact than the gap itself. Absence is treated as fine — the check only flags functions that are present and non-native. It is N/A on a non-Chrome UA or when window.chrome is missing entirely.
How to resolve it
Remove puppeteer-stealth-style polyfills of chrome.csi / chrome.loadTimes. Real Chrome exposes them as native functions or not at all, so the honest options are a real Chromium build or leaving them absent; a JS stub is strictly more revealing than the missing member it replaces.
Read in the wild by
PerimeterX / HUMAN
Walks window.chrome, chrome.app and chrome.runtime, requiring every function-typed member to stringify as {[native code]}; separately sums the constructor-string lengths of webstore, runtime, app, csi and loadTimes into a single reported field.
main.min.js (PerimeterX collector, [site]): `ky(t){if(t){try{for(var n in t){var e=t[n];if(hR(e)===ie&&!kz(e))return!1}}catch(t){}return!0}}` where `function kz(t){return hR(t)===ie&&new RegExp("\\{\\s*\\[native code\\]\\s*\\}","").test(""+t)}` and ie="function"; applied inside `AQ()` as `ky(Ax)`, `ky(Ax[Ay])`, `ky(Ax[Az])` with `Ax=hS[jb("Y2hyb21l")]` and `hS=window` (=window.chrome), `Ay=jb(hQ(509))`='app', `Az=jb(hQ(510))`='runtime'. Separately `AA=[hQ(511),Az,Ay,"csi","loadTimes"]` (hQ(511)='webstore') drives `AO(){…for(var n=0,e=0;e<AA[hQ(155)];e++)try{n+=(Ax[AA[e]].constructor+"")[hQ(155)]}catch(t){}t+=n+Av;…}` (hQ(155)='length', Av="|"), emitted as `t["PSkIY3hPCVE="] = AO()` → EV2 "PSkIY3hPCVE=" = "109|66|66|70|80", whose leading 109 is the summed total (Object 35 + Function 37 + Function 37 for app/csi/loadTimes; webstore and runtime absent so.constructor throws and is swallowed), not a per-member list.
Every attribution traces to a published artifact. See the sources and their limits.
Nearby checks in Automation surface
- Content Security Policy is enforced
csp-bypassThe audit excludes data: scripts. Execution despite script-src is direct CSP-bypass behavior. - the browser will not resolve a filesystem path the page invented
synthesized-path-entry-sandboxThis row does not measure a fingerprint. It measures whether the browser will help a page enumerate what is installed on the machine, and it… - no stylesheet is injecting custom properties into every page
injected-root-custom-propertiesA deployed commercial agent reads six CSS custom properties from the document's root element and reports true when four or more of them… - window.chrome present for a Chrome UA
chrome-objectThis is a cross-check, not a probe of window.chrome's contents: it first decides whether the browser claims to be Chrome (a Chrome/ token in… - window.external is shaped the way the engine generates it
window-external-shapeA deployed commercial agent lists the absence of this object among its own named failure messages, which means it treats window.external… - no notifications-permission headless bug
permissions-notification-bugTwo independent APIs describe the same underlying notification permission: navigator.permissions.query({name:'notifications'}) returns a… - permissions.query is native (arity throw + stack shape)
permissions-query-stackThis probe calls navigator.permissions.query() with exactly zero arguments and inspects the error the native arity check produces. - timer handles are a real per-realm counter
timer-id-sequencingThe number setTimeout hands back is not a token, it is an index into the realm's own timer table — so it carries structure that a fabricated…
Clearcote is a browser built for fingerprint coherence
It is a Chromium fork, maintained by the same people who wrote this reference. It ships as a compiled browser rather than as a stealth script injected into someone else's — which is a description of how it is built, and is not an argument about how it behaves on this check.
This audit takes no position on how Clearcote scores on Automation surface checks, on this one, or anywhere else. It has no baseline corpus of other people's fingerprints to rank you against and no vendor scoreboard — nearly every check is self-referential, asking one browser the same question through two independent APIs and reporting whether both answers can be true at once. It runs identically on any browser, including ours. Run it on yours and read the result yourself.
See the other checks in Automation surface — the family chrome-native-stubs belongs to.