Convert PNG to WebP on Mac — Free Browser Tool, No Install Required

Mac's built-in Preview app cannot save images as WebP. But you have two free alternatives that require no extra software: a browser-based converter that works in Safari, and a terminal command if you prefer the command line. Both handle batch conversion and preserve transparency.

Here is how to convert PNG to WebP on any Mac.

Method 1: Browser Converter — Works in Safari

1. Open the PNG to WebP converter in Safari, Chrome, or Firefox
2. Drag your PNG files from Finder into the browser window
3. Set quality — 80 for web use, 100 for lossless. The default works well for most images
4. Click Convert and download. For multiple files, use Download All as ZIP

This works on any Mac regardless of macOS version. No Homebrew, no terminal, no app installation. The conversion processes in your browser — files stay on your Mac.

Best for: quick conversions, batch processing (drag all files at once), when you want visual file size feedback before downloading.

Method 2: Terminal With cwebp (Google Official Tool)

Google provides an official WebP encoder called cwebp. Install via Homebrew:

brew install webp

Single file:

cwebp -q 80 input.png -o output.webp

Lossless:

cwebp -lossless input.png -o output.webp

Batch convert all PNGs in a folder:

for f in *.png; do cwebp -q 80 "$f" -o "$(basename "$f" .png).webp"; done

cwebp gives you the most control: quality, lossy/lossless, alpha compression quality, preprocessing filter strength, and more. If you are a developer optimizing images for a build pipeline, this is the best tool.

Note: macOS does not have cwebp pre-installed. You need Homebrew first (/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"). If you do not want to install Homebrew, the browser method works without any installation.

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Why Mac Preview Cannot Save as WebP

Mac Preview can open WebP files (since macOS Big Sur), but it cannot save or export as WebP. The Export dialog only offers JPEG, PNG, TIFF, PDF, and HEIC.

This is an Apple design choice, not a technical limitation. Apple added WebP reading support to macOS but has not added WebP writing to Preview. It is the same story with their other apps — Safari displays WebP, Photos can view WebP, but no built-in Apple app exports to WebP.

Your options:

• Browser converter — no install, works immediately
• Terminal (cwebp) — needs Homebrew but gives maximum control
• Third-party apps — Pixelmator Pro and Affinity Photo can export as WebP, but they cost money ($50-$70)

For simple format conversion, the browser tool is the path of least resistance on Mac.

Automate PNG to WebP on Mac

If you convert PNGs to WebP regularly, you can create a quick action:

Using Shortcuts (macOS Monterey+):

1. Open the Shortcuts app
2. Create a new shortcut
3. Add "Run Shell Script" action
4. Enter: for f in "$@"; do cwebp -q 80 "$f" -o "$(echo "$f" | sed 's/.png$/.webp/')"; done
5. Set "Pass input" to "as arguments"
6. Save and add to Finder Quick Actions

Now you can right-click any PNG in Finder and convert it to WebP from the context menu. This requires cwebp to be installed via Homebrew.

For a simpler automation that does not require Homebrew, bookmark the browser converter — it is always one click away and handles batches with ZIP download. Our Mac PNG to JPG guide covers similar Mac-specific workflows for JPG conversion.

Frequently Asked Questions

Can Mac Preview save images as WebP?

No. Preview can open and display WebP files but cannot export to WebP format. Use a browser-based converter (works in Safari) or install cwebp via Homebrew for terminal-based conversion.

What is the easiest way to convert PNG to WebP on Mac?

Open a browser-based converter in Safari, drag your PNG file in, and download the WebP. No installation, no account, no terminal commands. Takes about 10 seconds.

How do I batch convert PNG to WebP on Mac?

Browser method: drag all PNGs at once into the converter, download as ZIP. Terminal method: brew install webp, then run "for f in *.png; do cwebp -q 80 "$f" -o "$(basename "$f" .png).webp"; done" in the directory with your PNGs.

Does macOS natively support WebP?

macOS Big Sur and later can display WebP images in Safari, Preview, and Photos. But no built-in Apple app can create or export WebP files. You need a browser tool, cwebp, or a third-party app.