BMP vs PNG: When Should You Use an Uncompressed Bitmap?
BMP (Bitmap) is one of the oldest image formats still in common use, dating back to early Windows, and it takes a fundamentally different approach than PNG: little to no compression at all. That makes for enormous file sizes compared to PNG doing essentially the same visual job, which raises the fair question of why BMP is still around.
What "uncompressed" actually means here
A standard BMP file stores each pixel's color value directly, with minimal to no compression applied. PNG, by contrast, applies genuine lossless compression — no visual data is discarded, but the file is packed more efficiently, typically resulting in a file a fraction of the size of an equivalent BMP for the exact same image. There's no visual quality difference between the two for a given image; the difference is purely in file size and, correspondingly, how efficiently that image data is stored.
Why anyone would choose BMP over PNG today
A handful of specific technical contexts still favor BMP's simplicity. Some older or specialized software (certain legacy Windows applications, some hardware and embedded systems, particular image-processing pipelines) either expects BMP specifically or benefits from BMP's lack of compression, since decompressing an image takes processing time that an uncompressed format skips entirely. In performance-critical or resource-constrained contexts — real-time image processing, some game development texture pipelines, hardware with limited processing power — that decompression step, however small, can matter, which keeps BMP relevant in fairly narrow but real technical niches.
Why BMP isn't a good general-purpose choice
Outside of those specific contexts, BMP's lack of compression is a straightforward downside: the same image takes up dramatically more storage space and takes longer to transfer over a network or attach to an email, with zero visual quality benefit to show for it. For sharing images, posting online, or general everyday use, PNG (or another compressed format appropriate to the content) accomplishes the same visual result far more efficiently, which is exactly why BMP never became a general-purpose web or sharing format the way PNG did.
A simple way to decide
If a specific piece of software or hardware explicitly requires BMP, use BMP — that requirement exists for a real technical reason in that context. For everything else — sharing, storing, posting, emailing — PNG (for graphics needing transparency or lossless quality) or JPG/WEBP (for photos) will produce a smaller, more practical file with no visible downside. If you've been handed a BMP and don't actually need its specific properties, the image converter and BMP to JPG convert it into a far more space-efficient format in seconds, and Compress Image can shrink the result further if needed.