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BMP to JPG Converter - Convert BMP to JPG Free Online

Convert BMP to JPG in your browser and turn an uncompressed bitmap into a file a fraction of its size. Batch conversion is supported, and nothing is uploaded to a server.

What BMP to JPG Does

This tool decodes your BMP onto an in-browser canvas and re-encodes the pixel data with the browser's own JPG encoder. The size difference between the two files is the whole point, and it comes entirely from how each format stores pixels. A BMP, in nearly every common variant, is uncompressed: the file holds the raw bytes of every pixel in sequence, row by row, behind a small header. A 1920x1080 image at 24 bits per pixel therefore costs around 6 MB regardless of what it depicts — a detailed photograph and a flat grey rectangle occupy the same space. JPG works the opposite way. It converts the image into frequency components, discards the ones the eye is least likely to notice, and entropy-codes what is left, so that same 1920x1080 photo usually lands in the low hundreds of kilobytes. The saving is real, but it is achieved by throwing data away rather than packing it more cleverly. Two things follow from that. First, the conversion is one-way: BMP is lossless, so every pixel in it is original, and once the JPG encoder has run, the detail it dropped is gone for good. The Quality slider, running 1 to 100 with a default of 92, controls how much gets dropped. Second, 32-bit BMP files can carry an alpha channel and JPG cannot store transparency at all, so transparent pixels are composited onto white before encoding. What the tool does not change is the image itself — output width and height match the input exactly.

Why You'd Convert BMP to JPG

BMP files are enormous because they store pixels raw. Almost anywhere you send an image, JPG is both smaller and better supported.

Shrink multi-megabyte bitmaps exported by Paint, old scanners, or industrial equipment down to a manageable size
Get under an email attachment limit that a single uncompressed BMP would blow past
Publish on the web, where browsers and phones handle JPG but treat BMP as legacy
Slim down a folder of archived BMP scans before backing it up

How to Convert BMP to JPG

Four steps, all of them local — the bitmap is decoded, re-encoded, and handed back without ever touching a server.

1

Drop in one BMP or a whole folder of them — every file in the run uses the same settings

2

Set the Quality slider; 92 is the default, while 75-85 gives noticeably smaller files

3

Apply the conversion — the button reads "Converting..." while the encoder works through your files

4

Download each JPG on its own, or take the whole batch as a single ZIP

Frequently Asked Questions

Because standard BMP applies no compression at all. The file stores the raw bytes of every pixel one after another, so its size is simply width times height times bytes per pixel, plus a small header. A 1920x1080 24-bit image is about 6 MB whether it is a busy photograph or a blank white canvas — the content makes no difference. Formats like JPG and PNG both compress that same pixel data, which is why they end up dramatically smaller.
For photographic content, expect a reduction on the order of 90-95% at the default quality — a 6 MB BMP commonly lands somewhere between 200 KB and 600 KB. Flat graphics, screenshots, and line art vary more, since JPG handles hard edges poorly and needs more data to encode them cleanly. Exact numbers depend on image content, dimensions, and the quality value you pick, but a large drop is the normal outcome from any uncompressed source.
Yes, some. BMP is lossless, so it holds the original pixel values exactly; JPG is lossy and always discards a portion of the fine detail, which is how it reaches those file sizes. At the default quality of 92 the difference is very hard to see on a photograph. Screenshots, diagrams, logos, and anything with sharp text or hard color boundaries show it more clearly, because those are the patterns JPG compression handles worst.
Start at the default of 92 for photos and scans; it is generous enough that artifacts stay invisible in normal viewing. Drop to 75-85 when size matters more than pixel-level fidelity, such as email attachments or bulk uploads. Below roughly 60 you will see blocky patches in smooth gradients and halos around edges. There is no universally correct number — check one representative image at your chosen setting before committing a large batch to it.
It is filled with white. Some 32-bit BMP files carry an alpha channel, but JPG has no alpha channel at all, so transparency cannot survive the conversion in any form. This tool composites your image onto a white canvas before encoding, which is why transparent regions come out white rather than black or corrupted. If you need to keep the alpha data, convert to PNG or WebP instead — both store transparency properly.
Use PNG. It compresses losslessly, so the pixel values that came out of your BMP are preserved exactly while the file still ends up far smaller than the uncompressed original — typically a large saving on flat graphics and a more modest one on photos. It also keeps an alpha channel if your BMP had one. The Convert Format tool handles BMP to PNG when losing detail is not an acceptable trade.
No. The decode and the re-encode both happen in your browser through the canvas API, so the image data never leaves your device. That matters more than usual here, because BMP files from scanners, medical equipment, and industrial systems are often both sensitive and very large. It also means batch size is limited by your device's memory rather than an upload cap, and the tool keeps working offline once the page has loaded.
Yes. Add as many as you like and they all run through the same Quality setting in one pass, then download individually or as a single ZIP. Because one quality value applies to the whole batch, mixed content can come out uneven — a photo scan and a flat diagram respond very differently to the same number. Note also that uncompressed BMPs are memory-hungry to decode, so very large batches may run slowly.

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