CONVERT
JPG → BMP
Tap to choose your fileDRAG. DROP. DONE.
Upload any file and our engines will handle format detection automatically.
Max 25 MB · Free plan · No signup required
Convert to:
Detecting available formats...
Optimize for
Leave empty to use original name. Extension added automatically.
Uploading...
Processing your file...
Convert JPEG to uncompressed BMP format for legacy application compatibility.
JPEG compresses image data by discarding frequencies the human eye is least sensitive to, a process that permanently removes information from the original pixel grid. Every JPEG save cycle — open, edit, save — compounds that loss. BMP (Windows Bitmap) stores each pixel as raw, uncompressed RGB or RGBA values with no spatial frequency encoding at all, so the decoded result you see is the exact byte sequence stored on disk. When you convert a JPG to BMP, the decompressed pixel values from the JPEG decoder are written directly into the BMP raster without any re-encoding step that could introduce additional distortion. The resulting file represents the cleanest possible extraction of the data that survived the original JPEG compression. This makes the conversion relevant in legacy imaging pipelines, certain Windows automation contexts, embedded hardware workflows, and any tool chain where downstream software refuses JPEG input or requires a container with a fixed, predictable stride and no dependency on a DCT decoder.
JPEG Image
Source formatJPEG is the most widely used lossy image format on the web. It achieves small file sizes through adjustable compression, making it ideal for photographs and complex images where some quality loss is acceptable.
BMP Image
Target formatBMP 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.
Why convert JPG to BMP
The most concrete reason to go from JPG to BMP is tool or platform compatibility. Microsoft Paint in older Windows versions, many legacy medical and industrial imaging SDKs, and some embedded vision systems process BMP natively but treat JPEG as an optional dependency. Game sprite pipelines using GDI or Direct2D sometimes load BMP directly into device-independent bitmaps without an intermediate codec step. A second reason is stopping the lossy cycle: if you need to edit and re-save an image repeatedly, switching to BMP after the first decode prevents any further DCT-based quality degradation. The third reason is raw pixel access for computer vision preprocessing, where code reads BMP scanlines directly with a fixed byte offset rather than depending on a JPEG library.
HOW TO CONVERT
JPG → BMP
Provide the JPG
Click or drag to upload. We accept a single JPG file per job, with an optional queue of additional images for batch mode.
Encode to BMP
The conversion decodes the JPG, resolves the colour space to sRGB and writes the BMP container around the pixel data.
Save the BMP
The download is streamed back over HTTPS. If you uploaded multiple files, a ZIP with all BMP outputs is produced instead.
Common Use Cases
Share across platforms
Send BMP files to anyone without worrying about whether they have the right software for JPG.
Embed in documents
Drop BMP output into Word, Google Docs, PowerPoint, Notion or a website without conversion warnings.
Optimize size
BMP often produces smaller files than JPG for web, email and storage.
Archive & future-proof
Store in a widely-supported format that will still open on future operating systems without legacy plugins.
JPG vs BMP — Strengths and limitations
What each format does best, and where it falls short.
JPG Strengths
- Excellent compression ratio for photographs (10:1 or better without visible quality loss).
- Universal support — every camera, phone, OS, and browser reads JPEG natively.
- Adjustable quality setting balances file size against visual fidelity.
- Embeds EXIF metadata (camera model, GPS, exposure) automatically.
- Progressive rendering for graceful loading over slow networks.
Limitations
- Lossy — every save degrades the image further (generation loss).
- No transparency channel (use PNG or WebP for that).
- Visible compression artifacts on text, sharp edges, and flat colors.
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.
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).
JPG vs BMP — Technical specifications
Side-by-side comparison of the technical details.
JPG
- MIME type
- image/jpeg
- Compression
- Lossy — Discrete Cosine Transform + quantization + Huffman coding
- Color depth
- 8 bits per channel (24-bit RGB or 8-bit grayscale)
- Max dimensions
- 65,535 × 65,535 pixels (baseline)
- Transparency
- Not supported
- Typical quality
- 75–90 for web, 95+ for print
BMP
- MIME type
- image/bmp
- Compression
- None (typical); RLE 4/8 bit (rare)
- Extensions
- .bmp, .dib
- Color depths
- 1, 4, 8, 16, 24, 32 bits per pixel
- Byte order
- Little-endian
| Specification | JPG | BMP |
|---|---|---|
| MIME type | image/jpeg | image/bmp |
| Compression | Lossy — Discrete Cosine Transform + quantization + Huffman coding | None (typical); RLE 4/8 bit (rare) |
| Color depth | 8 bits per channel (24-bit RGB or 8-bit grayscale) | — |
| Max dimensions | 65,535 × 65,535 pixels (baseline) | — |
| Transparency | Not supported | — |
| Typical quality | 75–90 for web, 95+ for print | — |
| Extensions | — | .bmp, .dib |
| Color depths | — | 1, 4, 8, 16, 24, 32 bits per pixel |
| Byte order | — | Little-endian |
JPG vs BMP — Typical file sizes
Approximate file sizes for common scenarios.
JPG
- Phone photo (12 MP, quality 85) 2–5 MB
- Web thumbnail (400px) 20–60 KB
- Full-page magazine photo 500 KB – 2 MB
- Social-media square (1080×1080) 100–400 KB
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
Quality & Compatibility
BMP in its standard 24-bit form stores three 8-bit channels per pixel, matching the sRGB output of a JPEG decoder. The conversion preserves what the JPEG decoder outputs exactly — including any blocking artifacts, chroma subsampling halos, and ringing around sharp edges that the original JPEG compression introduced. Nothing new is lost, but nothing that was lost when the JPEG was first created is recovered. Standard Windows BMP does not carry an embedded ICC color profile, so any sRGB tagging in the JPEG's APP2 segment is dropped. JPEG EXIF metadata (orientation, camera model, GPS) is also discarded since BMP has no metadata block. The output file size grows substantially: a 1920x1080 image at 24-bit depth becomes roughly 6 MB as BMP versus 200–500 KB as a typical JPEG, because there is no compression whatsoever.
Tips for Best Results
- If your downstream tool requires a specific BMP bit depth — for example 8-bit indexed or 32-bit with alpha — confirm whether JPEG's lack of a transparency channel causes problems before converting. JPEG stores no alpha, so any 32-bit BMP produced from it will have a fully opaque alpha channel padded in by the converter.
- BMP scanlines are stored bottom-up by default per the Windows DIB specification, which surprises code that assumes top-to-bottom raster order. If pixel rows appear vertically flipped in your application after loading the converted BMP, check whether it reads the biHeight field sign correctly.
- After converting, do not open and re-save the BMP as JPEG to reduce file size unless you are done editing. Each JPEG re-encode introduces a new round of lossy compression on top of the artifacts already present from the original JPEG, accelerating visible quality degradation.
Frequently Asked Questions
It depends on the codecs involved. If both JPG and BMP are lossy, the pixels are re-encoded and a small amount of detail is discarded — invisible at default quality settings on photographs. If BMP is lossless (PNG, TIFF, BMP) the output keeps every pixel of the decoded JPG exactly, but cannot recover detail that JPG had already compressed away.
Often yes, especially when BMP is lossless. JPG tuned for efficient web delivery will usually produce smaller files than BMP's default settings. If file size matters, drop the quality in Advanced or pick a more compressed target format instead.
KaijuConverter uploads over HTTPS, processes the image in an isolated container and deletes both the source and the output within two hours. No account is required, file contents are never logged, and we do not use uploads to train any model. For confidential material, the paid plan includes a data-processing agreement.
RELATED CONVERSIONS
Other popular pairs involving JPG or BMP
More from JPG
More ways to reach BMP
Related comparisons
See these formats side by side to understand which fits your use case best.
Related Guides
BMP Bitmap Format: The Complete Technical Guide
Everything about the BMP format: DIB header variants, pixel storage, color depths (1 to 32-bit), RLE compression, alpha channels, and BMP vs PNG vs TIFF.
Read guideBMP Format: Windows Bitmap Images Explained — Headers, Compression & Use Cases
Learn what BMP files are, how the Windows Device Independent Bitmap format works, supported colour depths, compression options, and when to use BMP vs PNG.
Read guideBMP Bitmap Format: Complete Technical Guide to Windows Bitmap Images
Learn BMP (Windows Bitmap): BITMAPINFOHEADER structure, pixel encoding, color palettes, RLE compression, and raster fundamentals for legacy graphics.
Read guideSecure & Private Conversion
Your files are encrypted during transfer, processed in isolated containers, and automatically deleted within 60 minutes. We never read, share, or store your data.