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Formats

What is read and what is removed.

Files are told apart by their first bytes, not their names. Each format has its own parser, written for this page and small enough to read. This is the whole list.

Read and cleaned

  • JPEG .jpg, .jpeg

    Read
    EXIF (camera, lens, dates, GPS, owner, serial numbers, the embedded thumbnail), XMP, IPTC and Photoshop resources, comments
    Removed
    All of it. The ICC colour profile stays so the colours do not shift. If the photo was shot sideways, one orientation value is written back so it still displays the right way up.

  • PNG .png

    Read
    tEXt, zTXt and iTXt text chunks (including XMP), eXIf, tIME
    Removed
    All of it. The colour profile stays.

  • Word .docx

    Read
    core.xml, app.xml and custom.xml (author, last saved by, company, manager, revision, editing time, custom properties), the first-page thumbnail; the names on comments and tracked changes
    Removed
    The three property parts are emptied, the thumbnail is dropped and every zip entry's own timestamp is reset. Comment and tracked-change authors are shown, not removed: that is an edit to the document, so it stays your call.

  • Excel .xlsx

    Read
    core.xml, app.xml and custom.xml, the thumbnail
    Removed
    The three property parts are emptied, the thumbnail is dropped, the zip timestamps are reset.

  • PowerPoint .pptx

    Read
    core.xml, app.xml and custom.xml, the thumbnail
    Removed
    The three property parts are emptied, the thumbnail is dropped, the zip timestamps are reset.

  • PDF .pdf

    Read
    The Info dictionary (author, creator, producer, title, subject, keywords, dates) and the XMP packet
    Removed
    Info values and an uncompressed XMP packet are blanked in place, same length, so nothing else in the file moves. A compressed XMP stream, which is what Word and Acrobat usually write, is shown and kept, and the page says so. Metadata inside compressed object streams is not read yet.

Not yet

Dropping one of these tells you it cannot be read. Nothing is sent either way.

  • Video and audio .mp4, .mov, .m4a, .m4vNot yet. The udta and meta atoms are on the list.
  • GIF and TIFF .gif, .tif, .tiffNot yet.
  • Photoshop .psdNot yet.
  • Legacy Office .doc, .xls, .pptNot yet. The binary formats need a different parser.
  • OpenDocument .odt, .ods, .odpNot yet.

Six formats, all of them on your machine.

Drop one on the home page and see the table for your own file.

Clean a file