Does converting BMP to WebP lose quality?

WebP is lossy, so some data is discarded. At quality 80-85 the result is visually indistinguishable from the BMP source for photographic content. For logos, screenshots and line art, use lossless mode to keep edges perfectly crisp.

More about converting BMP to WebP

BMP is windows bitmap. BMP's total lack of compression makes it painful to store or move. Converting to WebP typically cuts 95% or more off the file with no visible change, which is why BMP archives are among the biggest wins this converter produces.

WebP is the default currency of fast web pages — smaller than JPEG at the same visual quality, smaller than PNG while keeping transparency, and supported by every browser in use. In practice that means a page that loads faster on mobile, a better Largest Contentful Paint score, and less CDN bandwidth — for the same picture. BMP files are 15-40x larger than WebP — a 2 MB WebP becomes a 35 MB BMP, so this is usually the single biggest weight saving available on a page built from them.

Plan for the size: BMP output is roughly width x height x 3 bytes regardless of what the picture contains. Resize before converting if the destination caps file size. WebP tops out at 16383 pixels on either edge, so anything larger is scaled to fit; for the vast majority of web work that ceiling is nowhere near a constraint.

When you'd use this

Reasons to convert BMP to WebP usually come down to compatibility, file-size, or specific feature requirements. Common situations:

  • An app or platform only accepts WebP uploads.
  • You need a feature unique to WebP (e.g. transparency, vector scaling, animation, multi-page pages, etc.) that BMP doesn't provide.
  • You're optimising file size — modern formats often produce smaller files than the older format you started with.
  • You need a single archival format across a project so files behave consistently in the same viewer.

How to do it in webp.now

  1. Open the BMP → WebP tool on webp.now.
  2. Drag your BMP file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
  3. The output is fixed to WebP. If the format supports extra options (page size, transparency background, quality, EXIF stripping), tweak them in the right-hand panel.
  4. Click Convert. The job runs on our server and finishes in a few seconds for typical photos.
  5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

Tips and common pitfalls

  • Quality 80-85 is the sweet spot for photographs — visually indistinguishable from the original at normal viewing sizes, and roughly a third the weight of the equivalent JPG.
  • Use lossless WebP for logos, icons, screenshots and line art. Lossy compression puts visible fuzz around hard edges and text.
  • Convert from the highest-resolution BMP you have and let the resize option produce the display size — downscaling before compressing beats compressing then downscaling.
  • Strip metadata for web delivery. EXIF blocks can add tens of kilobytes to a file nobody will ever read them from.
  • Serve WebP through a element with a JPG fallback if you still support very old browsers or need images to survive email clients.
Try the BMP → WebP tool
Free, no signup required. Files deleted in 24 h.
Open BMP → WebP
Back to all FAQ