Ghost Mode hides you from friends on Snap Map, and Snapchat documents that your location is still shared with Snap while you are in it. The location permission in your phone's settings is a different switch, and it is the one that stops Snapchat receiving your position at all.
Do they get told?Snapchat documents that the friends you pick for location sharing are not notified when you choose them. For Ghost Mode and for turning the app's location permission off, no notification is documented; Snapchat documents only that you stop being visible to anyone else on the Map. It also documents that your last position can sit on Snap Map until it expires, after 24 hours when the device permission is set to Only while using.
Do they get told?A notification to friends is not documented for Ghost Mode. What Snapchat does document: your location won't be visible to anyone else on the Map, and your own Bitmoji holds up a blue sign with a ghost icon unless you are sharing your live location. Snapchat also documents that your location is still shared with Snap.
Who can still see you
Off
Your friends on Snap Map
Your location won't be visible to anyone else on the Map until the timer you pick runs out.
Still on
Snapchat itself, and other apps
Snapchat documents that Ghost Mode limits sharing with friends, not with the Snapchat app, and other apps keep their own permission.
Still visible
The network, and Map Snaps
Your carrier and your IP address still place the phone, and Snaps you submit to Snap Map can still show up on the Map.
Snapchat prints three timer choices — 3 hours, 24 hours, or Until Turned Off — and its own pages place the Map Settings gear both in the bottom right corner and at the top of the Map screen.
Do they get told?Snapchat documents that the friends you pick are not told: "Friends you select aren't notified when you choose them." Snapchat also documents that only friends you've chosen to share your location with can see where you're at on Snap Map.
Who can still see you
Off
The friends you leave out
They stop seeing your position on Snap Map, and Snapchat documents that the friends you select are not notified when you choose them.
Still on
The friends you keep selected
They still see your live position, and Snapchat keeps receiving your location while the app holds the permission.
Still visible
The network, and screenshots
Your carrier still places the phone, and Snapchat documents that your location may appear in screenshots and Map Snaps friends take.
Snapchat prints the same choice on the Map itself: open the Map, tap the gear icon at the top of the Map screen, then tap Only These Friends or My Friends, Except…
Do they get told?A notification to friends is not documented for turning off Snapchat's location permission. What Snapchat documents is how long your last position lingers: set to Always it stays on Snap Map until you turn it off or it expires, and set to Only while using it expires after 24 hours. Snapchat also documents that your location data may still be cached after you turn permissions off.
Who can still see you
Off
Snapchat on this Android phone
Snapchat stops receiving your position from Android, so there is nothing new for it to put on the Map.
Still on
Every other app on the phone
Your phone's location stays on for every other app, and Android keeps its own location services running.
Still visible
The network, and cached data
Cell towers and your IP still place the phone, and Snapchat documents that location data may still be cached after permissions are off.
Snapchat's own help page prints a shortcut instead: press and hold the Snapchat app icon, tap App info, tap Permissions, tap Location, then choose DENY.
Location spoofing, fake-GPS apps and mock-location settings are outside this site on purpose. This page describes the settings the app and your phone provide, and what the vendor documents about them.
If someone is tracking you against your will, turning a setting off may not be the safest first step. Read this first.
Every platform this site carries for Snapchat is on the
Snapchat guide.