sailfish-browser-next153

Experimental Gecko ESR153 (Firefox 153) browser for Sailfish OS 5.1 and 5.2.

Sailfish OS ships a browser based on Gecko ESR91 from 2021; this is a community port of the current ESR153 engine, the successor of my ESR140 port (sailfish-browser-next).

Installs alongside the stock browser

Every package in this stack carries a "-next153" suffix and uses its own directories and profile. The system browser is not touched, and the ESR140 "-next" stack can stay installed as well — all of them appear in the app grid and can be used side by side. Uninstalling the -next153 packages leaves everything else exactly as it was.

Installation

Enable this repository and install ONLY this package. The dependencies (xulrunner-qt5-next153, embedlite-components-qt5-next153, qtmozembed-qt5-next153 and the three sailfish-components-webview-qt5-next153 packages) are pulled in automatically. Download is roughly 70 MB, installed size around 200 MB.

The app grid entry uses a purple icon, so it is easy to tell apart from the stock browser's blue one.

New in this release: extensions

WebExtensions work. Open the menu, tap the puzzle-piece icon, and search addons.mozilla.org from inside the browser — installing, enabling, disabling and removing all work from there.

Tested and working:

• uBlock Origin — filtering, including its dynamic rules
• Cookie-banner blockers (I still don't care about cookies) — banners are removed on load
• Tampermonkey — installs and its settings page opens; running userscripts not verified yet
• Social Fixer for Facebook (in desktop view; it targets the desktop layout)

Extensions are on by default. Earlier builds needed a pref set by hand, so a fresh profile silently had none.

What works

• Mobile layout and a mobile user agent (Firefox/153 Mobile) — sites no longer render in desktop mode
• Touch: tap, scroll, flick, pinch zoom, double-tap zoom; long-press context menu and text selection
• Dialogs (alert/confirm/prompt), HTTP authentication
• FIDO2 / WebAuthn security tokens over USB, including PIN entry — registration and login tested with a YubiKey on webauthn.io
• Downloads with the native Sailfish transfer UI
• Camera and microphone access (WebRTC / getUserMedia) with permission dialog
• Sign-in popups that close themselves (Google OAuth), landscape orientation

For developers: remote debugging

The Firefox devtools protocol is available, off by default. To turn it on, add these to ~/.local/share/org.sailfishos/browser-next153/.mozilla/user.js and restart the browser:

user_pref("devtools.debugger.remote-enabled", true);
user_pref("devtools.debugger.prompt-connection", false);
user_pref("devtools.chrome.enabled", true);
user_pref("embedlite.devtools.enabled", true);
user_pref("embedlite.devtools.port", 6000);

The server then listens on port 6000 on localhost and speaks the standard remote debugging protocol, so anything that talks RDP can attach — Firefox's about:debugging, or a terminal client for evaluating chrome-privileged JavaScript, which is how most of the extension work was debugged.

To reach it from another machine, forward the port over SSH rather than opening it up:

ssh -L 6000:localhost:6000 defaultuser@<device>

There is a devtools.debugger.force-local pref that would make the server listen on all interfaces. Don't set it: the protocol grants full chrome privileges with no authentication, so anyone on the same network could read your cookies and run code in the browser.

Known issues

• Extension popups — the small panel a toolbar button opens — are not shown yet. Extensions that are configured through a popup (VPN clients, for instance) can be installed but not set up. In progress
• Context menu entries added by extensions are missing
• ID Austria login (login.id-austria.gv.at) reports a wrong password even with the correct one; the password arrives byte-exact, the site rejects the session. Affects the ESR140 port as well. Under investigation
• Occasional crash on first start; restarting usually succeeds
• Rear camera delivers frames but shows a still viewfinder on the Xperia 10 V (device HAL issue)

This is alpha software. Tested on Sony Xperia 10 V (pdx235) with SFOS 5.2.0.15 and on the Jolla Phone 2026 with SFOS 5.1, both aarch64. Reports from other devices are very welcome — please include the device model and SFOS version.

Sources

Engine and EmbedLite layer: https://github.com/smatkovi/gecko-dev (branch fork-esr153) JS components: https://github.com/smatkovi/embedlite-components (branch next153) Browser UI: https://github.com/smatkovi/sailfish-browser (branch next153)

Release notes and direct RPM downloads: https://github.com/smatkovi/gecko-dev/releases/tag/esr153-alpha1

Support this work

This port was built in my free time. If you find it useful:

https://www.paypal.me/smatkovi https://liberapay.com/smatkovi