Question 1

Why did Microsoft eventually replace BMP as the default format in Paint?

Accepted Answer

In 2017, Microsoft updated Paint in Windows 10 to save as PNG by default instead of BMP. After nearly 30 years, the uncompressed format was too wasteful for modern displays — a single 4K screenshot as BMP weighs over 24 MB. PNG and WebP achieve 80-95% compression without visible quality loss, making BMP's raw pixel storage an artifact of an era when CPU cycles were too expensive for on-the-fly decompression.

Question 2

How much smaller will the WebP be compared to BMP?

Accepted Answer

Dramatically smaller — typically 95-99% reduction. A 6 MB BMP photograph becomes roughly 100-300 KB as WebP. Even screenshots with sharp text and flat colors shrink by 90%+. WebP achieves this through both lossy (VP8) and lossless compression modes, both far more efficient than BMP's zero compression.

Question 3

Does BMP-to-WebP preserve transparency?

Accepted Answer

Yes. 32-bit BMP files with an alpha channel will have their transparency preserved in the WebP output. Most BMP files are 24-bit (opaque), but if yours has transparency, WebP supports full per-pixel alpha — unlike JPG, which would flatten it to white.

Convert BMP to WebP

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