What is file metadata and why inspect it before sharing?
Whenever you snap a photo with your mobile device or save a document in desktop software, the file contains more than just the visible pixels or written text. It carries an extensive layer of data about data, known as metadata.
In digital photographs (JPEG, HEIC, PNG, TIFF, and WebP), metadata is structured using international standards like EXIF (Exchangeable Image File Format), IPTC, and XMP (Extensible Metadata Platform). In office documents and spreadsheets (PDF, DOCX, XLSX, PPTX), properties follow the Dublin Core schema and OpenXML Extended Properties.
File Formats & Exposed Properties Overview
| File Format | Commonly Exposed Metadata | Risk Level | Privacy Impact |
|---|---|---|---|
| JPG / HEIC / TIFF Photos | GPS (Lat/Lon/Alt), Camera Model, Lens, Timestamp, Serial Number | Critical | Exposes home address, routine, travel routes, and hardware. |
| PDF Documents | Author Name, Title, Creating Application (Acrobat, Word), Modification Date | Moderate | Discloses author identity, editing workflows, and software versions. |
| Word / Excel / PowerPoint | Last Modified By, Company, Total Editing Minutes, Revision Number | Moderate | May reveal negotiation drafts, internal corporate staff, and team names. |
| PNG / WebP Images | Editing software (Photoshop, Figma, GIMP), text chunks & comments | Low | Identifies graphic tools and embedded comments or color profiles. |
| MP3 Audio / MP4 Video | ID3 Tags, Artist, Album, Recorder Model, Video Geotag | Moderate | Identifies recording gear and capture location. |