Instagram has three separate location switches, and turning one off leaves the other two on. The Instagram map at the top of your inbox decides who sees where you are, a location tag is added to one post at a time, and the app's permission in your phone's settings is a third switch that Instagram's own page calls separate from the map.
Do they get told?Instagram documents notifications in one direction only. Its map page says you are notified when someone requests to see your location, and that people who asked are not notified when you decline their request. A notification to the people you were sharing with when you stop sharing is not documented anywhere on these pages, for the map, for a post's location tag, or for the app's permission in your phone's settings.
Do they get told?A notification to the people you were sharing with is not documented on Instagram's map page. What Instagram does document runs the other way: you are notified when someone requests to see your location, and people who asked are not notified when you decline.
Who can still see you
Off
People you shared with on the map
Instagram stops showing you on the map to the accounts you had chosen, and your Settings icon shows a red dot instead of a blue arrow.
Still on
Instagram itself and the rest of the app
Instagram's page says location services can still be on for Instagram, so post tags, chats and the phone permission are all untouched.
Still visible
Your carrier and any site you open
Your network still places your phone roughly by cell tower and IP address, and a location you type onto a post is a separate thing you publish.
Instagram prints the same four steps for Android and iPhone; Share Location at the bottom is the save button on that screen, not the switch itself.
Do they get told?Whether the account you hide from is told is not documented on Instagram's page. What is documented for the neighbouring hidden-places setting is that when you are inside a hidden place, no one will see you on the map.
Who can still see you
Off
The accounts you picked
They stop seeing you on the Instagram map, while everyone else you share with keeps seeing your location update.
Still on
Everyone else you share with
Your location keeps updating for the rest of the accounts you chose, and the phone's location permission is not affected.
Still visible
Chats and the network
A location you send yourself in a chat still shows where you were, and your carrier and IP address still place your phone roughly.
Do they get told?A notice to anyone else is not documented on either Instagram's or Google's page for this switch. What Instagram documents is its own side: the map's Settings icon shows you an orange triangle when the app has no device permission, and nothing about what anyone else sees.
Who can still see you
Off
Instagram on this phone
Google's Don't allow option means the app cannot use your location, even when you're using the app.
Still on
Every other app, and Android itself
The phone's own location setting stays on, every other app keeps its own permission, and locations already on your old posts stay there.
Still visible
Your carrier and the network
Cell towers and your IP address still place your phone roughly, and Instagram can still read a rough area from the connection you use.
Google prints a second route to the same screen: touch and hold the Instagram icon, tap App info, then tap Permissions and Location.
Do they get told?Whether anyone is told when you take a location off a post is not documented on Instagram's page. What is documented is what the tag does while it is there: when people tap the location in your post they can see it alongside other content tagged at the same place on the Instagram map.
Who can still see you
Off
Anyone tapping the post's location
The post stops carrying a place name, so it drops off that location's page on the Instagram map.
Still on
Your other posts and the map
Every other post keeps its own tag, and your map sharing and the phone's location permission are separate switches.
Still visible
The picture itself
A recognisable street, sign or skyline still places the photo, and anyone who already saw the tag may remember it.
Instagram's Android page prints this as Tap Remove next to Select a Location, then Tap Done to save your changes.
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 Instagram is on the
Instagram guide.