Nearly every file format has a place for metadata, but the amount and the risk differ a great deal. This guide lists the common formats, what they usually hold and the tool that cleans them.
| Format | What it can hold | Risk | Tool |
|---|---|---|---|
| JPEG, HEIC, PNG, WebP | Camera, lens, date, GPS, software, AI prompts, Content Credentials | High (GPS) | Image, HEIC |
| RAW (CR2, NEF, ARW, DNG) | Camera and lens serial numbers, owner name, GPS, dates | High | RAW photos |
| MP4, MOV, MKV, WebM | GPS track, device, creation date, encoder, titles | High (GPS) | Video |
| MP3, M4A, FLAC, WAV, OGG | Title, artist, comments, cover art, recorder details, dates | Medium | Audio |
| Author, producer, dates, XMP, earlier revisions, embedded photos | High | ||
| DOCX, XLSX, PPTX | Author, company, last saved by, thumbnail, folder path, editing IDs | High | Documents |
| ODT, ODS, ODP | Author, generator, template path, custom fields | Medium | OpenDocument |
| EPUB | Author, publisher, dates, purchase record | Medium | EPUB |
| SVG | Generator comments, RDF author and licence, editor settings | Low to medium | SVG |
| GIF | Comments, XMP | Low | GIF |
| ZIP | File dates, comments | Low to medium | ZIP |
Formats with almost nothing
Plain text, CSV, JSON and source code files have no metadata block. They still have a file name and a modified date in the file system, which are not part of the file itself and are not sent when you copy the text. BMP images and raw PCM audio have almost no metadata either.
Metadata outside the file
Your operating system keeps its own records beside a file: the created and modified dates, the owner, and on some systems the place it was downloaded from. These are not sent when you email the file, but a ZIP archive can carry the dates of its entries, which is why cleaning a ZIP matters when you pack a folder.