BMP to JPEG Image Converter

BMP: simple, faithful and enormous

The bitmap format, saved with the .bmp extension, is one of the oldest image types on Windows. It stores pixels in a very direct way, usually with little or no compression. That makes BMP easy for software to read and write, which is why you still meet it in Microsoft Paint exports, older scanners, industrial cameras, medical and lab equipment, point-of-sale systems, embedded displays and software written decades ago.

The price is size. Because each pixel is stored more or less raw, a full-colour BMP of a 12 megapixel picture can run to roughly 36 MB, while the same image as a good JPEG may be well under 3 MB. BMP files are slow to email, awkward to upload, and many websites and forms refuse them outright.

The BMP to JPEG Image Converter solves that problem. It reads your bitmap on our server and writes a compact JPEG, a format accepted almost everywhere, with your choice of compression, size and print resolution.

The trade you are making

BMP is effectively lossless; JPEG is lossy. Converting means accepting a small, controlled loss of detail in exchange for a dramatic reduction in file size. For photographs and scans that is nearly always a good deal: at 80% quality or above, most people cannot tell the two apart on screen. For pixel art, screen captures of software, or technical images with single-pixel lines, JPEG compression can blur edges, and a lossless target like PNG is safer. Use Convert to PNG in those cases.

Uploading a BMP: one hurdle first

Each upload is limited to 10 MB on the server. Because bitmaps are so large, this is the limit BMP users hit most often. As a rough guide, a 24-bit BMP uses about 3 bytes per pixel, so a file under 10 MB holds up to around 3.3 million pixels, for example 2000 by 1600. If your bitmap is bigger than 10 MB, save a smaller copy from the program that produced it, or export it in a compressed format there, before using this page.

The upload box on this page is set to BMP images, so your file dialog lists .bmp files straight away. You can also drag a BMP from your folder onto the upload area.

Settings that matter for BMP sources

Open the Configuration card. Convert Format is already on JPEG.

• Quality (10% to 100%, default 75%) decides how hard JPEG compresses. For scans you will read or print, choose 80% to 90%. For web thumbnails, 60% to 75% saves more space.
• Resize Unit: bitmaps from scanners are often far larger in pixels than needed. Set Pixel and a Width, or Percent with both Width and Height (for example 50 and 50).
• DPI: scanner bitmaps often carry 200, 300 or 600 DPI. If you resize in Inch, Centimeter or Millimeter, the DPI field decides how many pixels each unit becomes; with the field empty, the server uses 96. You can also just type a DPI to stamp it on the output without resizing.

The summary badge next to Configuration repeats your choices, for example "JPEG · 85% · 50% × 50%", so you can confirm them before processing.

Converting step by step

1. Adjust Quality and, if useful, Resize Unit, Dimensions and DPI.
2. Drop one or more BMP files on the Select Images box or use Select File.
3. Check each card in the Upload Queue. It shows the BMP's file weight and pixel size.
4. Press Process on a card, or Process Queue to convert all of them with the same settings.
5. Look at the Output panel. The weight badge with its down arrow shows how much smaller the JPEG is; for bitmaps, reductions of 80% to 95% are common.
6. Click Download. The file name is your original name with a random prefix and the .jpeg extension.

Examples from real use

Old Paint drawings and screenshots

Older versions of Windows Paint saved screenshots as BMP by default. If those images contain photos, convert at 80%. If they contain menus and text, consider PNG instead, or use JPEG at 90% or higher.

Scanner output for an online application

A flatbed scan saved as BMP at 300 DPI might be 2480 by 3508 pixels and too heavy to upload. Convert to JPEG at 80% and resize to Pixel width 1240 to bring it down to a portal-friendly size while keeping text legible.

Machine and instrument images

Microscopes, inspection cameras and lab devices sometimes export BMP. For reports and emails JPEG is fine; for measurement or analysis, keep the original bitmap, since JPEG alters pixel values slightly.

Advice

• Archive the original BMP if it is the only lossless copy you have.
• Resize generously. A display image rarely needs more than 2000 pixels on its long side.
• Run one test file before processing a large batch, so you can tune Quality once.
• Click the output thumbnail to inspect text and fine lines at full size before downloading.

Don'ts

• Do not use JPEG for images that will be measured, analysed or compared pixel by pixel.
• Do not set Quality very low on scans with small print.
• Do not upload bitmaps above 10 MB; the server rejects them.
• Do not expect transparency handling. If a 32-bit BMP carries an alpha channel, JPEG cannot keep it.

Other limitations

• Accepted inputs are JPG, JPEG, PNG, GIF, WEBP, JIFF and BMP.
• Width, Height and DPI must be whole numbers.
• Processing several files together applies one configuration to all, and one failing file causes the batch to report an error.
• Embedded metadata is stripped by default; orientation tags, if any, are applied.
• No crop, rotate, flip or zoom controls are available here.
• Files added with From URL (one address per line) come back without their original names.

Server-side processing

This converter uploads your bitmap to our server, where a server-side image library performs the conversion. The resulting JPEG is embedded in the response as Base64 for your browser to download, and the server deletes its temporary copy afterwards. Nothing is processed locally in the browser, and no account is needed.

Want a smaller, more modern file instead? BMP to WEBP produces even lighter files for the web.

Frequently Asked Questions