Convert BMP to WebP Online
Convert Windows BMP bitmaps to modern WebP. No upload, no registration.
.webp, .png, .jpg · up to 50 MB
BMP to WebP Converter
Why convert BMP to WebP?
Massive size reduction
Uncompressed BMP → WebP 90–95% smaller with no visible quality loss.
Full privacy
Conversion happens in your browser. Your images never leave your device.
Modern web compatible
WebP is Google's recommended web image format, supported by all modern browsers.
No installation needed
No Photoshop, GIMP, or any software required. Works in any browser.
How it works
Three steps, no hassle
Upload your BMP file
Drag or select your .bmp file. Works with Paint images, Windows screenshots, and scanner output.
In-browser conversion
Your BMP image is converted to WebP directly on your device. Nothing is sent to any server.
Download the WebP result
See the size reduction before downloading. WebP files are typically 90–95% smaller than the original BMP.
FAQ
Got questions?
BMP (Bitmap) is an uncompressed format created by Microsoft in the 1980s for the Windows environment. Every pixel is stored as-is, with no compression algorithm applied. A 1920×1080, 24-bit BMP image takes exactly 5.93 MB regardless of image content. That is why Windows uses it internally for the clipboard and many legacy scanners and industrial cameras default to it.
The reduction is dramatic — typically 90–95% compared to the original BMP. A 6 MB BMP can become a 300–600 KB WebP with virtually identical visual quality. WebP uses predictive coding and DCT transforms (lossy mode) or LZ77/LZW entropy coding (lossless mode), both far more efficient than BMP's raw pixel storage.
It depends on the mode. Lossless WebP is a pixel-perfect copy of the original BMP — just smaller. Lossy WebP introduces JPEG-like compression: at quality 85–90 the difference is imperceptible to the naked eye but technically present. For web distribution, lossy at quality 80–90 is the recommended standard.
Standard 24-bit BMP does not support transparency. A 32-bit BMP variant includes an alpha channel, but it is rarely produced by common software. If your BMP is 24-bit, the background is preserved as-is. If it is 32-bit with alpha, the conversion to WebP will correctly preserve transparency.
BMP remains relevant in specific contexts: Windows uses it internally for clipboard image data, industrial and medical scanners often export BMP for its lossless fidelity, some CAD and computer-vision applications use BMP for its simple and predictable structure, and certain embedded systems read BMP natively. Converting to WebP is the natural step before distributing or publishing these images.
WebP has universal support since 2020. Chrome supports it from version 23 (2012), Firefox from version 65 (2019), Safari from version 14 (2020, macOS Big Sur and iOS 14), and Chromium-based Edge from 2020. In practice, any browser updated in the last four years supports WebP without issues.
BMP to WebP online: convert Paint and scanner images without installing anything
BMP (Windows Bitmap) is one of the oldest image formats in the history of personal computing. Microsoft introduced it as part of the GDI (Graphics Device Interface) API in Windows in 1990, and it has since been the native format for the Windows clipboard and the default output of applications like Paint. Its longevity comes not from efficiency — quite the opposite — but from simplicity: BMP stores pixels raw, row by row, with no compression whatsoever (aside from an optional RLE variant rarely used in practice). This absence of compression guarantees absolute fidelity and maximum read/write speed, making it ideal for intermediate buffers, OS-level screenshot capture, and hardware output from industrial scanners, document cameras, and machine vision systems. The file size of a BMP is exactly width × height × bytes_per_pixel plus a 54-byte header. For a 1920×1080 image in 24-bit color, that is 5.93 MB regardless of whether the image is solid white or a detailed photograph.
WebP is a modern image format developed by Google, built on technology from the VP8 video codec and published in September 2010. Its lossy compression algorithm relies on block-based predictive coding using 4×4 pixel blocks and DCT transforms, achieving file sizes 25–35% smaller than JPEG at equivalent quality. The lossless mode combines color transforms, spatial prediction, and LZ77/LZW entropy coding, beating PNG by roughly 26% in size according to Google's own benchmarks. For BMP images from screenshots, scanned documents, or Paint output, the reduction compared to the original is especially dramatic precisely because the starting point — uncompressed BMP — is the least efficient possible format: reductions of 90–95% are routine. A 6 MB BMP can become a 300 KB WebP with quality indistinguishable to the human eye. WebP also supports an alpha channel (transparency) in both lossy and lossless modes, as well as animation (Animated WebP, similar to GIF but far more efficient).
The need to convert BMP to WebP arises in three main contexts. First, legacy archive migration: companies with large libraries of BMP images generated by industrial scanners, legacy document management systems, or CAD software need to migrate them to modern formats to reduce storage costs and improve load times in web applications. Second, Windows screenshot workflows: while Windows 10 and 11 have improved PNG support in the clipboard, many enterprise applications still paste images internally as BMP, and converting them to WebP before publishing on intranets or technical documentation significantly reduces page weight. Third, scanner and capture device output: many office scanners, industrial cameras, and machine vision systems export BMP for its simple, unambiguous structure. Convertir.ai performs the conversion entirely in your browser using the HTML5 Canvas API, without sending any bytes to external servers — making it safe even for confidential or sensitive images.