How to Strip GPS Metadata From Uploaded Images Before Publishing via Express

Developers publishing user-uploaded images via Express.js risk exposing GPS location data embedded in EXIF metadata if images are not properly sanitized before reaching a public URL. A four-stage pipeline is recommended: validate the upload, decode pixels into a new image object, re-encode a fresh file without application metadata, and then inspect the actual output bytes for any remaining location fields. The key insight is that checking the original file's metadata is insufficient — only auditing the final encoded output confirms no GPS data survived the process. A Python utility using Pillow can perform this audit in test workers or CI pipelines even when the request handler runs in Node.js. This approach is especially critical in apps like edtech platforms, where uploads from private locations could inadvertently expose a user's home address through seemingly harmless image files.