About PSD Files
Adobe Photoshop Document
PSD is the native file format for Adobe Photoshop, storing layered image data, masks, color spaces, and editing metadata. Converting PSD flattens layers into a single composite image.
Family
Raster & Vector Images
Extension
.psd
MIME Type
image/vnd.adobe.photoshop, application/x-photoshop
Can Use As
HOW PSD
CAME TO BE.
PSD — Photoshop Document — was born in 1987 when Thomas Knoll, a computer science student at the University of Michigan, wrote a display program called Display for his Mac Plus. His brother John, working at Industrial Light & Magic on Star Wars effects, convinced him to expand it into a photo editor. They sold the software — renamed Photoshop — to Adobe in 1988, and Photoshop 1.0 shipped in February 1990 on Macintosh.
PSD is the format's native save file: layers, masks, adjustments, smart objects, text, effects — all preserved in a single binary blob. The format has evolved through Photoshop versions without breaking backward compatibility: a PSD made in 1990 still opens in Photoshop 2026. It also became the lingua franca between designers and developers — every agency, studio, and enterprise graphics pipeline has at some point standardized on PSD hand-offs.
CURIOSITIES &
TRIVIA.
Photoshop 1.0 was coded by two brothers working from their parents' basement — Thomas wrote the image engine, John wrote the plug-in API.
The PSD format has a hard limit of 30 000 × 30 000 pixels per layer and 2 GB per file; beyond that you need PSB ("Photoshop Big").
Inside a PSD, layer data can be stored either uncompressed, RLE-compressed, or zip-compressed — editors pick based on content.
Many non-Adobe apps (GIMP, Affinity Photo, Krita) read PSD but rarely preserve 100% of the layer effects — adjustment stacks often break.
The file contains a flattened preview composite so apps that can't parse layers still render something reasonable.
STRENGTHS &
LIMITATIONS.
Strengths
- Preserves every Photoshop feature: layers, masks, adjustments, smart objects, text, effects, styles.
- Backward-compatible — files from 1990 still open in modern Photoshop.
- Industry-standard handoff format between designers, agencies, and prepress.
- Supports 32-bit HDR, CMYK, Lab, Duotone, and spot colors for professional print work.
- Rich metadata, color profiles, and printing instructions survive round-trips.
Limitations
- Proprietary — full fidelity only in Adobe tools; other apps approximate.
- File sizes are enormous (hundreds of MB is common for complex documents).
- Not a web format — browsers cannot display PSD natively.
- Binary structure is complex and version-dependent; parsers often lag the latest Photoshop version.
- Hard 2 GB / 30 000 px limit forces professionals to switch to .psb for large artwork.
Typical Sizes & Weights
Simple 2-layer logo
500 KB - 3 MB
Website mockup with 20 layers
20-80 MB
Magazine spread with hi-res photos
150-500 MB
Matte painting / CGI composite
1-4 GB
Technical Specifications
- MIME type
- image/vnd.adobe.photoshop
- Max dimensions
- 30 000 × 30 000 px (PSD); 300 000 × 300 000 (PSB)
- Max file size
- 2 GB (PSD); 4 EB (PSB)
- Color modes
- Bitmap, Grayscale, Duotone, Indexed, RGB, CMYK, Lab, Multichannel
- Bit depths
- 1, 8, 16, 32 bits per channel
CONVERT FROM
PSD
Common Use Cases
Graphic design, photo editing, layer-based image composition.
Related Formats
Popular comparisons
PSD vs JPG
Differences, file size, and when to choose each format.
PSD vs PNG
Differences, file size, and when to choose each format.
PSD vs WEBP
Differences, file size, and when to choose each format.
PSD vs AVIF
Differences, file size, and when to choose each format.
PSD vs GIF
Differences, file size, and when to choose each format.
PSD vs BMP
Differences, file size, and when to choose each format.
Popular PSD conversions
The most-requested destinations when starting from PSD.
Frequently Asked Questions about PSD
Frequently Asked Questions
PSD (Photoshop Document) is the native file format for Adobe Photoshop. It preserves layers, masks, adjustment layers, paths, and smart objects, making it the industry standard for professional image editing and design workflows.
PSD files open in Adobe Photoshop (full editing), GIMP (free, partial layer support), Photopea (free online editor), and Affinity Photo. For viewing only, XnView and IrfanView work well.
Use PSD during active Photoshop editing to preserve all Photoshop-specific features like smart objects and adjustment layers. Use TIFF for sharing layered files with non-Adobe software or for archival in a more universal format.