In one sentence
File metadata is the information a file carries about itself rather than its visible content, such as the GPS position and camera serial number in a photo or the author, company, software and editing time in a PDF or Word document, and it is shared every time the file is.
Why it matters
Metadata is written automatically. A phone photo usually records the date, the camera model and often the GPS position where it was taken. An Office file records who created it, the company name from the licence, who saved it last, the total editing time and the template. A PDF exported from Word keeps much of that in its document information and its XMP block.
For an investigator this is a free source: a single published file can give a real name behind a pseudonym, a home address from photo GPS, an internal user name format, or the software versions an organisation runs. For anyone publishing a file, it is an accidental disclosure.
Where it hides
- Photos (JPEG, HEIC, TIFF). EXIF tags hold the camera make, model and often its serial number, the date and time, the lens, and GPS latitude, longitude and altitude. XMP and IPTC blocks can add the photographer's name, copyright notes and editing history from photo software.
- Office files (.docx, .xlsx, .pptx). These are ZIP archives.
docProps/core.xmlholds the author, "last modified by", title, subject, keywords and dates;docProps/app.xmlholds the company, the application and version, the template and total editing time;docProps/custom.xmlholds custom fields such as sensitivity labels. Comments and tracked changes are stored in the document itself, with the reviewer's name. - PDF. The document information dictionary (Author, Creator, Producer, dates) and an XMP metadata stream. A PDF that was edited and saved again often keeps the earlier version inside the file, readable by anyone who looks.
Try it yourself hands-on
Carol Test is about to send a contract draft (contract.docx) and a site photo (site.jpg) to a client.
- Open the EXIF & Metadata Analyzer on the Strip metadata tab.
- Drop
site.jpginto the photo area. The tool lists what it found, including the GPS position if there is one, and gives you a cleaned copy. - In Documents: PDF, Word, Excel, PowerPoint, click Choose documents and pick
contract.docx. Each file shows what it holds (for example author Carol Test, company Example Corp, total editing time), what remains after cleaning, and what the tool cannot remove for you. - Read the Not removed list. Comments, tracked changes and earlier PDF versions are content, not metadata: accept or delete them in the editing program first.
- Click Download cleaned file and send that copy. Everything runs in your browser; nothing is uploaded.
Common mistakes
- Black boxes are not redaction. Drawing a rectangle over text in a PDF hides it on screen; the text is still in the file. Delete the text in the source document, then export.
- Visible content leaks too. A street sign, a reflection or a badge in a photo gives away the location even when the GPS tag is gone.
- Platforms differ. Some sites strip metadata on upload and some keep it; messaging apps that send "as a file" usually keep it. Clean the file yourself before sharing.