About BMP (Windows Bitmap)
BMP is the native bitmap format of Microsoft Windows, dating back to the earliest versions of the operating system. It stores an image as a plain grid of pixels, usually with no compression at all — the file on disk is essentially raw pixel data plus a small header.
That simplicity made BMP the default output of MS Paint, old screenshot tools, and decades of Windows software. Today you mostly run into BMP files when working with legacy programs, embedded devices, or tools that insist on an uncompressed input. There is rarely a reason to create new ones for anything web-facing.
Because BMP skips compression, files are enormous — a 12-megapixel photo lands around 36 MB. Converting to PNG keeps every pixel identical at a fraction of the size, while JPEG or WebP makes more sense for photos. Convertmaxxing does either directly in your browser: the file never leaves your device, and nothing is ever uploaded.
Strengths
- Lossless by nature — pixels are stored exactly, with no compression artifacts
- Opens in virtually anything, from 1990s software to modern browsers
- Trivial to read and write, which keeps it popular in embedded and low-level programming
- No patent or licensing baggage
Limitations
- Huge files — typically several times larger than an equivalent lossless PNG
- No meaningful compression in the variants most software actually supports
- Transparency support is inconsistent from one program to the next
- A poor choice for the web or email purely because of size