gpx.studio is a free online GPX viewer and editor which allows to:
• visualize multiple traces in different colors and aided by many different maps (cycling, hiking, satellite, etc)
• edit traces by adding, inserting, moving or deleting track points
• reverse traces
• add or change the timestamps of a trace
• view, add, edit and remove waypoints
• reduce the number of track points
• view and rework the structure of the file
• automatically add elevation data to traces if missing
• merge multiple traces, extending time, heart rate, cadence, power and temperature data where needed
• extract segments from traces and perform any other action while maintaining the segments' structure within files
• save the result on your computer or to your Google Drive™ to get a shareable link and embedding code