PNG is lossless — great for quality, terrible for file size. A single screenshot can be 2-5 MB as PNG. Converting to WebP typically shrinks it by 50-80% while keeping the image visually identical.
The fastest way for a few images. No software install, no upload to any server — everything happens in your browser.
The browser tool is ideal for occasional conversions. Your files never leave your device — the conversion uses Canvas API and runs entirely locally.
For bulk conversion or automation, Google's cwebp tool is the gold standard:
# Install (macOS)
brew install webp
# Convert single PNG to WebP
cwebp -q 85 input.png -o output.webp
# Convert all PNGs in a folder
for f in *.png; do cwebp -q 85 "$f" -o "${f%.png}.webp"; done
# Lossless conversion (keeps exact pixels)
cwebp -lossless input.png -o output.webp
Photoshop: Version 23.2+ supports WebP natively via File → Save As → WebP. Older versions need the free WebP plugin from Google.
GIMP: Built-in WebP export since version 2.10. File → Export As → select WebP format.
Squoosh (browser): Google's free tool at squoosh.app offers side-by-side comparison before exporting.
At quality 80-85, WebP is visually indistinguishable from PNG for most images. The difference only becomes noticeable below quality 50. For graphics with sharp text or thin lines, use quality 90+ or lossless mode.
WebP also supports full lossless mode — the file will still be 25-35% smaller than PNG while keeping every pixel identical.
Need to convert dozens of PNGs? Use cwebp in a script, or drag multiple files into a browser converter that supports batch processing. The key is to find the right quality setting — test with one file first, then apply the same setting to all.