cwebp

Compress a WebP file with default settings (q = 75) to the [o]utput file

$ cwebp [path/to/image_file] -o [path/to/output.webp]

$ cwebp [path/to/image_file] -o [path/to/output.webp] -q [100]

$ cwebp [path/to/image_file] -o [path/to/output.webp] -q [0]

$ cwebp [path/to/image_file] -o [path/to/output.webp] -resize [width] [height]

$ cwebp [path/to/image_file] -o [path/to/output.webp] -noalpha

cwebp [options...] -o output.webp input.png

-o file, --output=file
    Set output WebP file; stdout if omitted

-q float, --quality=float
    Quality factor 0-100 (default 75); higher is better

-lossless
    Encode in lossless mode

-lossless_near=quality
    Near-lossless encoding (0-100)

-m int, --compression=int
    Compression method 0 (fastest)-6 (slowest, best)

-preset preset
    Preset: none, photo, picture, drawing, icon, text

-alpha_quality=quality
    Alpha plane quality 0-100 (default 100)

-alpha_filter=method
    Alpha filtering: none, fast, best (default)

-sns=strength
    Spatial noise shaping 0-100

-size pixels
    Target file size in pixels

-psnr target
    Target PSNR in dB

-resize w h
    Resize output to width x height

-crop x y w h
    Crop input to x-offset, y-offset, width, height

-mt threads
    Max threads for multithreading (0=auto)

-metadata=all|none|icc|exif
    Copy metadata (default none)

-short
    Use fast encoding shortcuts

-framing 0|1
    Split into frames (for animation)

-loop count
    Loop count for animations (default infinite)

--
    End of options; treat rest as filenames

-v, --verbose
    Print verbose output

-h, --help
    Show help

-version
    Print version info

cwebp is a command-line utility from Google's libwebp library for encoding images into the WebP format, supporting both lossy and lossless compression. It excels at producing smaller file sizes compared to JPEG or PNG while maintaining visual quality, making it ideal for web optimization.

Key features include tunable quality settings (-q), advanced compression methods (-m), alpha channel handling for transparency, preset profiles for quick setups, and support for animated WebP via multi-frame inputs. Users can target specific file sizes (-size), PSNR values (-psnr), or apply spatial noise shaping for better quality at low bitrates.

It accepts inputs like PNG, JPEG, TIFF, and raw RGB/YUV, outputting single-frame or animated WebP files. Multithreading (-mt) speeds up processing on modern CPUs. cwebp is widely used in web development, image processing pipelines, and tools like ImageMagick. For best results, experiment with presets like photo, picture, or drawing via -preset.

Installation is via package managers (e.g., apt install webp) or compiling libwebp. It's lossless-capable but defaults to lossy mode unless specified.

Lossy mode irreversible; test quality visually. Large inputs may consume high memory. Animated WebP requires specific flags like -loop. Not all browsers support WebP fully.

cwebp -q 90 -m 6 input.jpg -o output.webp
cwebp -lossless input.png -o out.webp

cwebp -loop 10 frame*.png -o anim.webp for looping GIF-like WebP

Developed by Google as part of libwebp (first release 0.1.0 in 2010). WebP format announced May 2010 for efficient web images. cwebp evolved with VP8/VP9/AVIF influences; current stable ~1.4.x (2024). Widely adopted post-Chrome 9 support.

dwebp(1), webpmux(1), vwebp(1), gif2webp(1), img2webp(1), convert(1)