Overview
When your smartphone acquires a satellite location fix, Android uses Assisted GPS (A-GPS) via the Secure User-Plane Location (SUPL) protocol to quickly download satellite orbital predictions (ephemeris data), reducing the Time to First Fix (TTFF) from minutes to mere seconds.
However, standard Android implementations default to supl.google.com. Every time an app requests a GPS fix, Android sends an unencrypted or minimally protected packet containing your SIM card’s unique IMSI (International Mobile Subscriber Identity) alongside the cell tower IDs currently within range. This creates a persistent, unprompted location and identity telemetry leak directly to Google.
supl-replacer is a systemless privacy module that modifies gps.conf to redirect all SUPL requests to privacy-focused proxies hosted by the GrapheneOS project.
How It Protects Your Privacy
- GrapheneOS Proxy Integration: Replaces
SUPL_HOST=supl.google.comwith GrapheneOS’s secure proxy server (supl.grapheneos.org). - IMSI Stripping: The GrapheneOS proxy strips out your SIM card’s IMSI and local cell identifiers before relaying the ephemeris query upstream, returning fresh satellite almanac data without logging personal hardware identifiers.
- Preserved Fix Speeds: You retain instantaneous, sub-second GPS locks in navigation applications (Google Maps, OsmAnd, Waze) without transmitting unneeded telemetry.
Installation
- Download the latest
supl-replacer-v*.ziparchive from GitHub releases. - Install the module in Magisk.
- Reboot your device.
- Launch any GPS test application (such as GPSTest) to verify that A-GPS satellite fixes resolve promptly.