.psd File Extension
.psd file is, which apps open Photoshop documents, how Poly supports them, and when to export another image format. File extension details for .psd
Partial Support| File type | Adobe Photoshop document |
|---|---|
| MIME type | |
| Encoding | Binary, big-endian Photoshop document with an 8BPS signature |
| Operating systems | Windows, macOS, Linux |
| Opens with | Adobe Photoshop, Adobe Illustrator, Krita |
| Poly support | Yes. Poly recognizes .psd files and provides visual image features from their flattened rendering. |
| Indexed by Poly | Partial. Poly indexes the filename and visible composite for visual search, not layers or editable text. |
| Preview in Poly | Yes. Poly shows a flattened image preview rather than the editable layer stack. |
| Poly agent | Partial. The Poly agent can understand the visible composite but cannot inspect individual layers or hidden content. |
What kind of file is a .psd?
A .psd is an Adobe Photoshop document. It is a working file for layered raster artwork rather than just a finished bitmap. One document can preserve layers, masks, editable text, paths, effects, color information, and a flattened composite.1
The registered MIME type is image/vnd.adobe.photoshop. A PSD begins with the ASCII signature 8BPS, or 38 42 50 53 in hexadecimal, followed by format version 1. Checking both fields helps distinguish a real PSD from a misleading filename.12
.psd does not create a Photoshop document. Open and export the source with an image editor instead.How do I open a .psd on my computer?
Adobe Photoshop on Windows or macOS offers the most complete editing support. Adobe Illustrator can also use PSD files, while Krita provides a cross-platform option on Windows, macOS, and Linux.13
Compatibility outside Photoshop varies because applications may interpret editable text, effects, adjustment layers, and blend modes differently. Krita specifically cautions that complete compatibility with another application's native format is not realistic.3 If the appearance matters, compare the imported result with a trusted flattened preview before saving over the original.
Web browsers do not normally display PSD files directly. Export a PNG, JPEG, WebP, or AVIF copy for a website while retaining the PSD as the editable master.
Poly support for .psd
Poly gives PSD artwork a thumbnail, a flattened preview in the image viewer, visual search, and visual understanding by the Poly agent. This makes the visible design easy to browse and find without opening Photoshop.
The preview does not expose the layer stack, layer names, masks, paths, editable text objects, or hidden content. Those elements are not content-indexed, and words visible in the flattened artwork are not indexed as document text. Use a Photoshop-compatible editor when you need to inspect or change the document structure.
History of .psd
Thomas and John Knoll created the software that became Photoshop. Adobe released Photoshop 1.0 on February 19, 1990, which marks the practical beginning of its native document format.4 Layers arrived in Photoshop 3.0 in 1994 and helped establish PSD as an editable composition format rather than a simple flat image.5
Adobe documents PSD so third-party applications can read and write it, but the format remains under Adobe's control. IANA registered image/vnd.adobe.photoshop in December 2005 and lists .psd as its extension.1
Working with .psd and alternatives
Keep a PSD when layers, masks, type, and effects must remain editable. Adobe recommends the related Large Document Format, .psb, when a document exceeds PSD's 2 GB limit.6
| Property | PSD | PSB |
|---|---|---|
| Extension | .psd | .psb |
| Header version | 1 | 2 |
| Maximum dimension | 30,000 pixels | 300,000 pixels |
| Poly preview | Flattened preview | Not supported as PSD |
Choose an export based on the destination:
- PNG for a lossless flattened image with transparency.
- JPEG for compact, widely compatible photographs without transparency.
- WebP or AVIF for modern web delivery.
- OpenRaster for layered exchange between supporting editors, with possible differences in Photoshop-specific features.
- TIFF for print and image-interchange workflows where larger files are acceptable.
Flattening is a one-way simplification. An exported PNG can preserve the visible result, but it cannot reconstruct the original layers, masks, type objects, or adjustment settings.
Footnotes
- Internet Assigned Numbers Authority. image/vnd.adobe.photoshop Media Type Registration. ↩ ↩2 ↩3 ↩4
- Adobe. Adobe Photoshop File Formats Specification. Defines the PSD and PSB signatures, versions, structure, dimensions, and image resources. ↩
- Krita project. PSD File Format. Describes supported Photoshop structures and compatibility limits. ↩ ↩2
- Adobe. Dreams from the Digital Darkroom: 25 Years of Photoshop. ↩
- Adobe. Celebrating 35 Years of Creativity, Community, and Innovation with Adobe Photoshop. ↩
- Adobe. Photoshop File Formats Overview. ↩