jbrowser.engine.identity

Generated from the source code of JBrowser 2.0.3.

jbrowser/engine/identity.py · 112 lines

The browser JBrowser presents itself as: the current Chrome version, as a Chromium browser.

Qt WebEngine would announce its own Chromium (140 in Qt 6.11) plus a QtWebEngine/x.y token, and a browser a year behind Chrome is treated as outdated or suspicious by some sites. JBrowser presents the newest stable Chrome version instead, consistently everywhere a site can look: the User-Agent header, navigator.userAgent, the Sec-CH-UA client-hint headers and navigator.userAgentData.

The user agent string is exactly Chrome's. The client-hint brands say "Chromium" (plus Chrome's placeholder brand) but not "Google Chrome": Google's sign-in knows a genuine Google Chrome by more than its brand, and rejects a browser that claims the brand without the rest ("Couldn't sign you in").

The version is recorded at build time: tools/chrome_version.py asks Google's version history service for the newest stable Chrome for Windows and rewrites the two constants below, and master.ps1 runs it for every release. A copy of JBrowser that hasn't been updated for a while keeps up by itself: every 30 days after the recorded date it presents the next major version. Chrome ships one every 4 weeks, so the estimate never runs ahead of the real Chrome.

Constants#

Functions#

chrome_version#

chrome_version(today: date | None=None) -> strsource

The full Chrome version to present, e.g. "155.0.8059.12".

major#

major(version: str) -> intsource

user_agent#

user_agent(version: str) -> strsource

Chrome's reduced user agent: only the major version is real, the rest is always zero.

grease_brand#

grease_brand(seed: int) -> tuple[str, str]source

The placeholder brand and version Chrome adds for major version seed, e.g. ("Not(A:Brand", "24").

brand_versions#

brand_versions(version: str) -> dict[str, str]source

Brand → full version, as a Chromium browser of this version reports them (Sec-CH-UA-Full-Version-List). No "Google Chrome" brand: see the module notes.

engine_version#

engine_version() -> strsource

The Chromium version Qt WebEngine is actually built on, e.g. "140.0.7339.225".

version_for#

version_for(choice: str | None) -> strsource

The version for Settings → Advanced → "How JBrowser introduces itself": the newest Chrome ("current", the default) or the engine's own Chromium ("engine").

apply#

apply(profile, version: str | None=None) -> strsource

Present version (default: chrome_version()) on a QWebEngineProfile. Returns the user agent.

firefox_user_agent#

firefox_user_agent(today: date | None=None) -> strsource

A current Firefox user agent for Windows. Firefox 140 came out on 2025-06-24 and a new version follows about every four weeks; counting 30 days per version never runs ahead.

apply_firefox#

apply_firefox(profile) -> strsource

Present Firefox on a profile, as consistently as Qt WebEngine allows (see engine/signin.py): the user agent in headers and JavaScript, no high-entropy client hints, and no browser brands in the Sec-CH-UA header or navigator.userAgentData (Firefox has neither).