CLIcwebpImageMagickffmpeg7 min read

Convert WebP Images via Command Line

Reference guide for cwebp, dwebp, ImageMagick, and ffmpeg. Batch one-liners for macOS, Linux, and Windows PowerShell.

Tool	Direction	Best for
cwebp	JPG/PNG → WebP	Encoding, quality control, metadata
dwebp	WebP → PNG/PPM	Decoding WebP, exact pixel output
ImageMagick (magick/mogrify)	Any ↔ Any	Batch, resize+convert in one step
ffmpeg	Any → WebP / animated	Video frames, GIF → animated WebP

Install the tools

# macOS (Homebrew)
brew install webp imagemagick ffmpeg

# Ubuntu / Debian
sudo apt install webp imagemagick ffmpeg

# Windows (winget)
winget install Google.WebPCodec
winget install ImageMagick.ImageMagick
# ffmpeg: https://ffmpeg.org/download.html

cwebp — encode to WebP

# Basic conversion (quality 85)
cwebp -q 85 input.jpg -o output.webp

# High quality (near-lossless)
cwebp -q 95 input.png -o output.webp

# Lossless mode (for logos, icons)
cwebp -lossless input.png -o output.webp

# With metadata stripping (smaller file)
cwebp -q 85 -metadata none input.jpg -o output.webp

# Resize to max 1200px width while converting
cwebp -q 85 -resize 1200 0 input.jpg -o output.webp
# (0 = auto-calculate height to preserve aspect ratio)

# Show encoding stats
cwebp -q 85 -v input.jpg -o output.webp

Batch: JPG/PNG → WebP

# macOS / Linux — convert all JPG in current folder
for f in *.jpg; do cwebp -q 85 "$f" -o "${f%.jpg}.webp"; done

# Include PNG too
for f in *.{jpg,jpeg,png}; do
  cwebp -q 85 "$f" -o "${f%.*}.webp"
done

# Windows PowerShell
Get-ChildItem *.jpg | ForEach-Object {
  cwebp -q 85 $_.FullName -o "$($_.BaseName).webp"
}

dwebp — decode WebP to PNG

# WebP → PNG (lossless, preserves transparency)
dwebp input.webp -o output.png

# WebP → PPM (for scripts that need raw pixels)
dwebp input.webp -ppm -o output.ppm

# Batch: all WebP → PNG
for f in *.webp; do dwebp "$f" -o "${f%.webp}.png"; done

ImageMagick — universal converter

# Convert a single file
magick input.jpg output.webp
magick input.webp output.jpg
magick input.webp output.png

# With quality control
magick input.jpg -quality 85 output.webp

# Lossless WebP
magick input.png -define webp:lossless=true output.webp

# Resize and convert
magick input.jpg -resize 1200x output.webp

# Batch convert (mogrify — overwrites originals by default!)
# Always use -path to save to a different directory
mkdir webp_output
mogrify -format webp -quality 85 -path ./webp_output *.jpg

# Windows PowerShell
New-Item -ItemType Directory -Force -Path webp_output
Get-ChildItem *.jpg | ForEach-Object {
  magick $_.FullName -quality 85 "webp_output\$($_.BaseName).webp"
}

Warning: mogrify without -path overwrites the original files. Always specify an output directory.

ffmpeg — animated WebP and video frames

# Static image → WebP
ffmpeg -i input.jpg output.webp

# GIF → animated WebP
ffmpeg -i animation.gif -c:v libwebp \
  -lossless 0 -compression_level 6 \
  -q:v 70 -loop 0 -preset picture \
  -an -vsync 0 output.webp

# Video → WebP (first 5 seconds, 15fps)
ffmpeg -i video.mp4 -vf fps=15 -t 5 \
  -c:v libwebp -q:v 80 -loop 0 output.webp