image/vnd.adobe.photoshop

Photoshop's native working file, layers and adjustment stacks intact — which is exactly why it does not belong on the web: a PSD is an editing project, not a deliverable, and browsers do not render it. Adobe registered the type with IANA in 2005 but keeps the format specification semi-closed, distributed with the Photoshop SDK, so third-party readers implement from a mix of documentation and archaeology. Every PSD opens with the bytes 8BPS, a fourcc inherited from the classic Mac file-type system. The x-flavored aliases image/x-photoshop and application/x-photoshop still float around older tooling.

.psd is the standard document; .psb is the large-format variant for files beyond 30,000 pixels a side.

Defined by IANA registration — image/vnd.adobe.photoshop · IANA registration. Registry facts from the IANA media-types registry via mime-db.