Checking.
Paste a coordinate pair — long-press a spot in Google Maps and it copies exactly this format.
You can also search for a place and use it as your start.
A page inside a frame only gets location if the page around it hands the permission down, and a desktop without GPS hardware falls back to a network lookup that can come back empty. Setting the start by hand does the same job.
The best loop that size from here crosses a border.
DeTour sizes the loop so the ride itself takes about this long, door to door.
DeTour is a route-planning app for drivers and riders who want more than the fastest way from A to B. Choose a destination and get a fast, scenic, or twisty route — or let DeTour surprise you with a random loop that starts and ends at home.