Simon Willison’s Weblog

Encoded Polyline Algorithm Format. Google Maps does some pretty crazy bit mangling to create compressed versions of lat/long pairs.

Posted 4th January 2008 at 4:12 pm

Recent articles

A new way to extract detailed transcripts from Claude Code - 25th December 2025
Cooking with Claude - 23rd December 2025
Your job is to deliver code you have proven to work - 18th December 2025

encoding 5 google-maps 53 latlong 1 polyline 1

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