What is file metadata?
Metadata is "data about data." For a file, that means details such as its name, size, type, when it was created or modified, who made it, and, for photos, which camera took it and where. You usually do not see metadata when you open a file, but it is there, and it often travels with the file when you share it.
It helps to separate two kinds:
- File system metadata is kept by your operating system, not inside the file: name, size, creation and modification dates, permissions, and on some systems tags or "where from" information.
- Embedded metadata is stored inside the file itself: EXIF data in photos, ID3 tags in MP3s, author and revision history in Office documents, and document properties in PDFs.
How metadata works
Embedded metadata is defined by each file format. A JPEG stores EXIF in a dedicated segment near the start of the file. A Word document (.docx) is a ZIP archive containing XML files, one of which lists the author, company, and creation and modification times. A PDF has a document information dictionary and may also include XMP metadata. Video files can store creation dates, device models and GPS coordinates.
File system metadata, by contrast, is not part of the file's bytes. When you copy or download a file, the destination system usually assigns its own creation date, and whether the modification date is kept depends on the method used.
| Metadata | Usually travels with the file? |
|---|---|
| File name | Yes |
| Photo EXIF, including GPS | Yes, unless something strips it |
| Document author and properties | Yes |
| Created and modified dates | Often reset, depends on method |
| Permissions and OS tags | Usually not |
Why metadata matters when sending files
Metadata can be useful: photographers rely on camera settings and capture times, and teams use document properties to track versions. But it can also reveal more than you intend. A photo might contain the GPS coordinates of your home. A document might show the name of the original author, the company it came from, or the software used. Before sending files to people you do not know well, or publishing them, it is worth checking what metadata they carry.
Example
You sell a used bike online and send the buyer a photo taken in your garage. The photo's EXIF data includes precise GPS coordinates. Anyone with a free EXIF viewer can see where it was taken. Removing the metadata before sending keeps the image but drops the location.
Metadata and Sendryo
Sendryo transfers files in original quality and never alters them, which means embedded metadata such as EXIF, GPS and document properties arrives intact. That is usually what photographers and professionals want. If you would rather not share it, strip photo metadata first with the free remove EXIF tool, which runs locally in your browser. File names are sent so the recipient can save files correctly. For more privacy tips, see the security page.