Photos stored as BMP are a common sight on older computers, old digital camera software, scanners and some industrial or medical systems. They look fine, but they are huge, because BMP stores every pixel uncompressed. Converting BMP photos to JPG makes them dramatically smaller, perfect for email, websites, messaging and printing services. This guide explains how the BMP to JPG converter works and how to choose settings.
Why JPG for photos
JPG is designed for photographs. It uses lossy compression that removes detail people rarely notice, especially fine colour variation, while keeping brightness and structure. The result looks the same at normal viewing size but takes a small fraction of the space.
A typical 3,000 by 2,000 pixel BMP photo is around 18 MB. As a JPG at the default quality it might be 1 to 2 MB. That difference decides whether a photo can be emailed, uploaded or shared at all.
When to choose PNG instead
JPG is not ideal for everything. Screenshots, diagrams, scanned documents with text and line drawings can show faint smudges around sharp edges when saved as JPG. For those images, BMP to PNG is lossless, keeps text perfectly crisp, and is often small enough anyway.
A simple rule: photos go to JPG, everything with text or sharp lines goes to PNG.
Choosing quality
The quality setting runs from 1 to 100.
- 85 (default): excellent for nearly all photos. Differences from the BMP are very hard to see.
- 90 to 95: for printing, cropping or archiving where you want to keep more detail.
- 70 to 80: for thumbnails, previews or when size is critical.
Avoid 100. The file grows considerably for no visible benefit.
Because BMP is uncompressed, your source has no existing compression artefacts. That makes BMP to JPG one of the cleanest lossy conversions you can do: the JPG is compressed only once, from a perfect original.
Step by step
- Open the BMP to JPG tool.
- Choose your BMP file or drag it onto the page. The real format is checked first.
- Adjust quality if needed.
- Press Convert to JPG.
- Download your file and check the new size on the result page.
A worked example: old family photos
You find a folder of family photos from an old computer, each saved as BMP and each around 10 to 20 MB. You want to share them with relatives over a messaging app, which refuses files that large. Convert them to JPG at quality 85. Each becomes a small fraction of its original size, and they send quickly while looking just as good on everyone's phones.
Keep the BMP originals on a backup drive if they are precious. Lossy compression is permanent, and the uncompressed originals are your best possible copies.
A worked example: an inspection report
An inspection camera saves photos as BMP. Your report software can attach JPG images but struggles with very large files. Converting at quality 90 keeps fine details visible for the report, while making each image small enough to include dozens of photos without the document becoming unwieldy.
What about transparency?
Most BMP files have no transparency. In the rare cases where a BMP does include a transparent channel, the converter fills those areas with a background colour you choose, because JPG cannot store transparency. White is the default.
Common mistakes to avoid
- Using JPG for screenshots and scanned text. Use PNG for those.
- Choosing very low quality to save space. Quality 80 to 85 is usually small enough.
- Editing and re-saving JPGs repeatedly. Do your edits on the original or a PNG, then export a final JPG.
- Deleting the BMP original of an important photo. Keep it, or keep a PNG copy, as a lossless master.
Limits
The tool page lists file size and dimension limits. Large BMP files may approach the upload limit because they are uncompressed. If a file is too big, you will be told before conversion begins.
Privacy
Your photos are processed privately and are never shared. Download links are personal and expire quickly. Uploaded and converted files are deleted automatically after a short retention period, and guest files are removed shortly after download.
Frequently asked questions
Will the JPG look worse than the BMP? At quality 85 or above, differences are very hard to see at normal size.
How much smaller will it be? Often around a tenth of the size or smaller for photos.
Is the original BMP modified? No. Your original file is never changed.
Should I convert screenshots to JPG? Usually not. PNG keeps text sharper.
A quick note on colour
Converting from BMP to JPG keeps colours accurate. JPG simplifies some fine colour detail, which is the main source of its savings, but the overall colours, skin tones and brightness remain faithful. If you notice colour blotches in very smooth areas such as clear skies, raise the quality setting a little.
Troubleshooting
Text in my image looks smudged. The image is probably a screenshot or document rather than a photo. Convert it to PNG instead, which keeps text perfectly sharp.
The JPG is still too large for a form. Lower the quality to 75, or resize the image before converting. Many forms only need a modest resolution.
The page says the file is not a BMP. Some programs give other formats a .bmp extension. The converter checks the real contents and tells you which tool to use.
Colours look slightly different. Compare both files in the same viewer. If you see blotches in smooth areas, raise the quality.
How much quality do you really need?
It is tempting to always choose the highest quality "just in case", but it is worth matching quality to the job:
- Sharing on social media or chat: 75 to 85. Platforms usually re-compress images anyway.
- Email to friends and family: 80 to 85.
- Websites: 75 to 85, ideally after resizing to the display size.
- Printing at home or a photo lab: 90 to 95.
- Archiving important photos: keep the BMP or a PNG copy, and use a JPG at 90 or more for everyday viewing.
In short
BMP to JPG is the quickest way to make large, uncompressed photos small enough to share, upload and print. Keep quality around 85, raise it for printing, and use PNG for screenshots and documents. Hold on to the BMP original for anything precious.