Question 1

How did BMP become the default image format on early Windows?

Accepted Answer

Microsoft introduced the BMP format alongside Windows 2.0 in 1988 as part of the Graphics Device Interface (GDI). Because it stored pixels in a format the display hardware could blit directly to the screen — no decompression step needed — it became the fastest format to render on the underpowered machines of the era. Windows Paint saved BMP by default for over two decades, ensuring billions of BMP files were created worldwide.

Question 2

How much smaller will the PNG file be?

Accepted Answer

PNG uses lossless DEFLATE compression, so the reduction depends on the image content. Screenshots with large flat-color regions often shrink by 80-90%. Photographs with complex textures may only shrink by 30-50%. Either way, the output is always smaller than the uncompressed BMP, and no pixel data is lost.

Question 3

Does BMP-to-PNG preserve transparency?

Accepted Answer

32-bit BMP files with an alpha channel will have their transparency preserved in the PNG output. Most BMP files are 24-bit (no transparency), in which case the PNG is fully opaque. Either way, what you see in the original is exactly what you get in the output.

Convert BMP to PNG

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