Find the flattest route between any two points in SF
Points and comments are a snapshot, not live.
Flatten SF finds the flattest walking or biking route between two points in San Francisco.
Flatten SF computes routes over 160,000 street segments using USGS 1m lidar elevation data and Overture/OpenStreetMap. A slider lets users trade off distance and cumulative climbing gain, showing 30 distinct routes from shortest to flattest. Stairways are allowed on foot, excluded on a bike. Climbing is cumulative gain, not net endpoint difference. The tool is offline for San Francisco intersections and addresses.
What commenters are saying
Commenters appreciated the tool's live profile updating and trade-off slider. Several reported routing bugs: a parser issue with a "slow street" tag prevented pedestrian access on Cabrillo St, and 22nd St in the Mission had a discontinuity. Some noted that Google Maps and Apple Maps already offer hill-avoiding routes, but argued those services prioritize bike lanes over flatness. A commenter pointed to bikehopper.org and hillmapper.com as alternative tools with better grade visualization. The creator fixed the Cabrillo bug and redeployed.