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How to convert WebP to PNG on a Mac and keep transparency
By Himanshu Ranjan · Updated 8 November 2026
Convert a WebP to PNG on a Mac when you need transparency or a lossless working copy. Open it in Preview and use File > Export with PNG, or select many files and run Convert › Convert to PNG in FileDial. Both work locally. The PNG will usually be larger than the WebP, which is normal.
When PNG is the right target
WebP can store a transparent background, and so can PNG. JPG cannot. That is the main reason to pick PNG when converting a downloaded WebP logo, icon, sticker or product cutout. PNG also uses lossless compression, built on DEFLATE, so saving to it does not discard pixel data the way a lossy format would.
PNG is also the safe choice for screenshots, UI captures and anything with sharp text or flat colour. Those images look crisp in PNG and tend to smear or show halos in JPG.
Steps in FileDial
FileDial converts a selection in one pass and writes a new PNG beside each WebP. The original is left alone, and the result card shows the size before and after so you can see what the change cost.
- Select the WebP files in Finder.
- Hold the right Option key (or right-click and choose Open in FileDial) to open the dial.
- Choose Convert, then release on Convert › Convert to PNG.
- Open the new PNG files beside the originals. Undo is available if you picked the wrong files.
The Preview route
Open the WebP in Preview, choose File > Export, set the Format pop-up to PNG and click Save. To convert several at once, open them in one Preview window, select them in the sidebar, then export. That is fine for a handful of files.
Check the result against a coloured background before you rely on it. A quick way is to drop the PNG on a slide or web page with a dark background; a stray white box means the original was never transparent to begin with.
Expect bigger files
The most surprising part of WebP to PNG is size. A lossy WebP photo can be a fraction of the size of the same picture as a PNG, because PNG stores every pixel exactly. Photos are a bad fit for PNG; flat graphics, logos and screenshots are a good one.
If your WebP is a photograph and you only need compatibility, JPG is the better target, see the WebP to JPG article. If you need transparency and a smaller file afterwards, run Compress › Compress on the PNG, which makes a smaller copy that FileDial describes as looking the same.
- Photos: choose JPG unless you need transparency.
- Logos, icons, screenshots: choose PNG.
- Animated WebP: PNG keeps one frame only.
Checking transparency after conversion
A converted PNG can look fine in Finder and wrong somewhere else, because Finder shows transparency against a light background. To check properly, place the file on a dark slide, a coloured web page or a design canvas and look at the edges. Pale halos around a cutout usually mean the original WebP had its edges blended against white, which no converter can undo.
If you find a halo, there are two honest fixes. Go back to the original source and export again with a transparent background, or run Adjust › Remove background on a clean version of the picture to get a fresh cutout as a transparent PNG beside the original. Do not try to patch halos by converting back and forth, since every extra lossy step makes edges worse. When the image is a logo, Convert › Image to SVG (trace)… is another route, because a vector has no halo problem at all, though it only suits logos, drawings and flat art.
- Test on a dark and a light background.
- Fix halos at the source, not with more conversions.
- Vectorise simple logos instead.
Mistakes to avoid
The most common mistake is converting a lossy WebP photo to PNG and expecting better quality. It will not be better, only larger. The second is assuming transparency exists. Many WebP downloads from product pages are opaque, with a white background baked in, so the PNG is opaque too.
Use Preview for a single file, since File > Export to PNG takes seconds. Reach for a batch tool when you have a folder of stickers or icons, or when you want to chain a second step such as Compress › Compress afterwards. If your goal is a smaller transparent graphic, converting to PNG is the wrong direction, because WebP already supports transparency with smaller files; the reason to go to PNG is compatibility, not size.
Local conversion and privacy
Web converters receive a copy of every file you drop on them. FileDial processes everything on your Mac and never uploads files. The only network traffic is the licence check and optional anonymous usage counts, which never include file names, paths or contents.
Questions
Does PNG keep the transparency from a WebP?
Yes, as long as the WebP actually had an alpha channel. PNG supports full alpha transparency. If the converted image shows a white or black box, the source file probably never had a transparent background and the colour was baked into the pixels.
Is PNG lossless compared with the WebP?
PNG compression is lossless, so saving to PNG does not add new loss. But if the WebP was lossy, the artefacts already in it are preserved, not repaired. You get an exact copy of what the WebP decoded to, not the pristine original photo.
Can I batch convert hundreds of WebP files?
Yes. Select them all in Finder and run Convert › Convert to PNG once. FileDial works in batches and saves each result as a new file. For reference, FileDial converted a batch of 300 photos in 5 seconds on a MacBook, though PNG output of large images can take longer.
Why is my PNG ten times bigger than the WebP?
PNG stores every pixel without discarding detail, while lossy WebP throws away data your eye barely notices. For photographs the difference can be large. Use JPG for photos, or compress the PNG afterwards, and keep PNG for graphics and transparency.