BMP vs HDR
A detailed comparison of BMP Image and Radiance HDR Image — file size, quality, compatibility, and which format to choose for your workflow.
Technical Specifications
| Specification | .BMP | .HDR |
|---|---|---|
| MIME type | image/bmp | image/vnd.radiance |
| Extensions | .bmp, .dib | .hdr, .pic |
| Compression | None (typical); RLE 4/8 bit (rare) | — |
| Color depths | 1, 4, 8, 16, 24, 32 bits per pixel | — |
| Byte order | Little-endian | — |
| Encoding | — | RGBE (shared 8-bit exponent) |
| Dynamic range | — | ~76 orders of magnitude |
| Creator | — | Greg Ward, Radiance renderer (1991) |
Strengths 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.
.HDR Strengths
- True floating-point dynamic range in 32 bits per pixel.
- Simple format — easy to parse and generate.
- Standard for environment maps and lighting probes in 3D.
- 30+ years of continuous use in architectural rendering.
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.
.HDR — Limitations
- No compression — files are larger than OpenEXR or AVIF for equivalent quality.
- Only one channel set (RGB) — no alpha, no multi-layer like EXR.
- Not a web format.
- Aging — OpenEXR is the modern professional choice.
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.
HDR (Radiance HDR Image) is an image format used to store raster graphics — a two-dimensional grid of pixels describing a picture. It is part of the raster & vector images family and designed around a specific trade-off between file size, visual fidelity, and feature support (transparency, colour depth, compression type). Photographers, web designers, and content creators choose HDR when its particular strengths match the publishing target.
BMP files open in Windows Paint, Photos, macOS Preview, GIMP, Photoshop, and virtually any image viewer. All Windows applications support BMP natively.
Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open HDR natively. On mobile, iOS Photos and Google Photos display HDR in the gallery when supported by the OS. If the format is rare or new, convert to JPG or PNG first — both are universally readable — using our HDR to JPG or HDR to PNG converter.
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.
Upload the HDR to KaijuConverter and pick a target format (JPG, PNG, WebP, HEIC, TIFF, BMP, SVG, PDF). The conversion runs in the browser via ImageMagick and returns a download in seconds. No account or installation required; both input and output delete automatically within two hours.
Need to Convert Gigabyte Archives or Mass Folders?
KaijuConverter delivers ultra-fast in-memory conversions for everyday tasks. For multi-gigabyte production workloads without browser bandwidth bottlenecks, explore high-throughput desktop suites.
One-time payment with zero recurring commitment: convert files up to 1 GB and 50-file batches for 24 hours.
Convert large videos, PDFs, and lossless audio directly in your browser—100% ad-free with priority queue.
High-throughput cloud pipeline for files up to 1,024 MB, 24-hour encrypted storage, and priority processing.
Convert thousands of camera RAW files (CR3, NEF, ARW) to WebP, AVIF, or TIFF in one pass.
GPU-accelerated RAW development with end-to-end 16-bit ICC color profile management.