UserScripts require a browser addon such as Violentmonkey (preferred) or Tampermonkey.
Some scripts may not work on Tampermonkey in Chrome.
Training Mode Script
GeoGuessr Training Mode 
Adds options to tag and save locations to Map Making App, show coverage lines, hide compass, enable terrain mode, hide car meta, and more.
Streak Scripts
Country Streak
Adds a country streak counter that automatically updates while you play.
State Streak
Adds a state/province/region streak counter that automatically updates while you play (may not work for all countries, depending on how they define their regions).
Hedge Streak
Adds a hedge streak counter that automatically updates while you play and tracks how many games in a row you score 20,000 points or more.
County Streak
Adds a county streak counter that automatically updates while you play (may not work for all countries, depending on how they define their counties).
Island Streak
Adds an island streak counter that automatically updates while you play. Currently supported countries: New Zealand, Indonesia, Japan, Greece, Philippines (Island Streaks GeoGuessr map).
Quad Streak
Draws a grid over the minimap, and tracks how many correct quads you guess in a row.
Post-War Europe Country Streak
Adds a country streak counter that uses European country borders from the post-war era, prior to the collapse of the Soviet Union.
Install Post-War Europe Country Streak
Custom Streaks
Streak script that allows you to use custom GeoJSON data for streaks. (How-to Guide)
Misc Scripts
(some may be broken due to GeoGuessr site changes)
Compass North Hotkey (N)
Press N to point the streetview map due north.
Install Compass North Hotkey (N)
Connect 4 Map Grid
Shows a grid overlay on the minimap and counts the streaks (map link).
Country Blitz
Get as many countries correct as you can within the time limit.
Exact Map Location Count
Shows the exact location count on the map page, rather than 50k, 100k, etc
Install Exact Map Location Count
Exact Round Time
Allows you to change the round time limit in 1 second increments instead of 10 seconds.
Expose Seed Quitters
Shows all players on the challenge results screen, even if they didn't complete all 5 rounds.
Games Played Counter
Shows how many games you have played and allows you to set a counter (click counter on the game screen to configure).
Google Maps - Hide Google Maps UI
Press 'H' to toggle Google Maps UI elements
Install Google Maps - Hide Google Maps UI
Hide Compass
Hides the compass
Hide Pano Author
Hides the copyright that shows the name of the author of the Streetview panorma.
Hide Party Link
Blurs out the party invite link (also pro league invite links) so people can't randomly join by typing the address (made for streamers/content creators).
Hide Score
Hides your score and guesses while playing the game and only shows it at the end.
Map Making App - Copy Tags
Copies tags and location counts to clipboard in Map Making App for pasting into a spreadsheet.
Install Map Making App - Copy Tags
Mosaic Multi
Divide the round up into tiles and reveal them one-by-one and score bonus points for using fewer tiles (made for NMPZ).
Only Car Only Compass
The long awaited sequel to No Car No Compass. Hides everything in the round except for the car and compass.
Results Select All Players
Selects all players on the results screen.
Install Results Select All Players
Save To Map Making App
Save locations to Map Making App after each round.
Install Save To Map Making App
View Country Leaderboards
View leaderboards for all countries, not just your own.
Install View Country Leaderboards
Visual Filters
Applies visual filters (brightness, contrast, hue, saturation, blur, etc) to the streetview map. (Edit the filters by clicking the button next to your score while in-game).
World Score Reference
See approximately what a round score would have been on a world map (while playing other maps e.g. country-specific maps).
miraclewhips