BMP vs PSD
A detailed comparison of BMP Image and Adobe Photoshop Document — file size, quality, compatibility, and which format to choose for your workflow.
BMP Image
Raster & Vector ImagesBMP is an uncompressed raster image format native to Windows. Files are large but preserve exact pixel data with no compression artifacts. Rarely used on the web due to file size.
About BMP filesAdobe Photoshop Document
Raster & Vector ImagesPSD 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.
About PSD filesStrengths Comparison
BMP Strengths
- Dead-simple format — trivially easy to read and write.
- Lossless and uncompressed — perfect bit-exact pixel storage.
- Universally supported in Windows applications since 1985.
- Supports 1, 4, 8, 16, 24, and 32-bit color depths.
PSD 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
BMP Limitations
- Enormous file sizes — no meaningful compression in typical use.
- Not a web format — browsers support it but nobody serves BMPs over HTTP.
- No metadata support (no EXIF, no ICC profile in practice).
- Multiple header versions mean "a BMP" is ambiguous — parsers must handle several variants.
PSD 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.
Technical Specifications
| Specification | BMP | PSD |
|---|---|---|
| MIME type | image/bmp | image/vnd.adobe.photoshop |
| Extensions | .bmp, .dib | — |
| Compression | None (typical); RLE 4/8 bit (rare) | — |
| Color depths | 1, 4, 8, 16, 24, 32 bits per pixel | — |
| Byte order | Little-endian | — |
| 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 |
Typical File Sizes
BMP
- Small icon (32×32) 4 KB
- Screenshot (1920×1080) ~6 MB
- 4K image (3840×2160) ~25 MB
- Scanned A4 at 300 dpi ~25 MB
PSD
- 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
Ready to convert?
Convert between BMP and PSD online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.
Frequently Asked Questions
BMP (Bitmap) is a raster image format developed by Microsoft for Windows. It stores images with no compression by default, resulting in large file sizes but pixel-perfect quality. It has been part of Windows since version 1.0.
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.
BMP files open in Windows Paint, Photos, macOS Preview, GIMP, Photoshop, and virtually any image viewer. All Windows applications support BMP natively.
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.
PNG is better than BMP in almost every scenario since it provides lossless compression (smaller files), transparency support, and wider cross-platform use. BMP is mainly relevant for legacy Windows applications.
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.