The page itself arrived over a network protocol
The document's navigation entry names a protocol when bytes were transferred and no service worker or cache was involved (severity: warn).
What a detector infers
Every page keeps a navigation timing entry for its own document. When the browser fetched it, nextHopProtocol names the protocol it used (h2, h3, http/1.1) and transferSize counts the bytes. When an automation client answers the request itself through the DevTools protocol (Fetch.fulfillRequest, a driver's route.fulfill, and some patched drivers on every load once they use init scripts), the bytes are counted but no protocol was used, so nextHopProtocol is empty.
The audit ignores the cases where an empty protocol is ordinary: a service worker answered (workerStart above 0), the page came from a cache or a prefetch (deliveryType set), or nothing was transferred. Measured on 2 November 2026: genuine Chrome 156 and Clearcote both report h2 for the same page.
How to resolve it
Let the browser fetch the document itself. If requests must be changed, change them on the network (a proxy) rather than fulfilling the main document from the driver.
Nearby checks in Automation surface
- No Puppeteer / Playwright sourceURL marker
sourceurl-leakPuppeteer and Playwright evaluation labels can appear in main-world Error stacks. - No controller code crossed the main-world canary
main-world-executionAn early DOM canary records main-world calls, but page code and extensions can also call it, so this is contextual. - No exposed Puppeteer / Playwright binding
exposed-binding-leaksExposed functions leave Playwright/Puppeteer registries, prefixes, source text, or __installed markers. - No global holds an unnamed native function
no-unnamed-native-globalsThe DevTools protocol lets an automation client put a function on the page with Runtime.addBinding, so page code can call back into the… - A popup opened without a user gesture is blocked
popup-blocked-without-gestureChrome blocks a window.open popup unless the page has a user activation, a click or key press in the last 5 seconds. - 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…
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 document-arrived-over-network belongs to.