Convert images to WebP or AVIF on your Mac, without uploading
By Himanshu Ranjan · Updated 8 November 2026
To convert images to WebP on a Mac with FileDial, select them in Finder, hold the right Option key and choose Convert › Convert to WebP. For AVIF choose Convert › Convert to AVIF, and to go back to a widely compatible format choose Convert › Convert to JPG. Every conversion makes a copy on your Mac; nothing is uploaded.
How to do it with FileDial
- Select the images in Finder.
- Hold right ⌥ to open the dial.
- Choose Convert › Convert to WebP or Convert › Convert to AVIF.
- Upload the new copies to your site; the originals stay beside them.
Your original file stays untouched. The result is saved beside it, and every result has Undo.
Which option to pick
| Tool | Use it when |
|---|---|
| Convert to WebPConvert | For web images; animated GIFs stay animated. Metadata isn't kept, which also strips camera and location details. |
| Convert to AVIFConvert | When you want an AVIF copy for sites and browsers that support it; new copy beside the original. |
| Convert to JPGConvert | When a WebP or other image needs to open everywhere; JPG copy beside the original. |
JPG vs WebP vs AVIF: which to use
JPG has been the default photo format on the web for decades. It is universally supported but uses an older compression method. WebP, developed by Google, compresses photos more efficiently than JPG at similar visual quality, supports transparency like PNG, and supports animation like GIF. All current major browsers display it.
AVIF is newer still. It is based on the AV1 video codec and can produce even smaller files than WebP at the same visual quality, especially for photos with smooth gradients. The cost is that encoding takes more work and support in older software is patchier, so some image editors and upload forms still refuse it.
A practical approach for a website: serve WebP or AVIF to browsers, and keep a JPG version for email, documents and anywhere that might not read the newer formats. Smaller images mean faster pages, which matters to visitors on mobile connections.
- JPG: works everywhere, larger files.
- WebP: smaller than JPG, transparency and animation, wide browser support.
- AVIF: often the smallest, newest, least supported outside browsers.
Why not convert with an online WebP converter
Website images can include unreleased product shots, client work and staff photos. Online converters require uploading those files to a third party. The FBI Denver Field Office said on 7 March 2025 that free online converters are increasingly being used to spread malware, with returned files that can lead to ransomware, while the sites scrape personal data.
Even well-meaning services can mishandle storage: in July 2024 Cybernews reported that PDF Pro and Help PDF left Amazon S3 buckets open, exposing 89,062 uploaded files. Converting on your Mac with FileDial avoids that exposure entirely, and works with Wi‑Fi off.
Other ways to make WebP or AVIF files on a Mac
Preview opens WebP and AVIF images on recent macOS versions, and File › Export lets you save to the formats listed in its Format menu. Check that menu on your Mac: if WebP or AVIF is not listed, Preview cannot create it, though it can still convert those files to JPG or PNG. Finder's Quick Actions › Convert Image offers JPEG, PNG and HEIF rather than web formats.
Developers often use command-line encoders, which are free and powerful but take setup. FileDial suits people who want to select a folder in Finder and get WebP or AVIF copies in one move, keep the originals, Undo any result, and batch hundreds of images without opening a terminal.
Questions
Does Convert to WebP keep animation?
Yes. According to the tool's own note, animated GIFs stay animated when converted to WebP. Metadata isn't kept, so camera and location details are not carried into the WebP copy.
Should I use WebP or AVIF for my website?
WebP has wider support today; AVIF is often smaller but newer. Many sites use one of them for browsers and keep a JPG for everywhere else. FileDial can make all three from the same originals.
Can I turn WebP images back into JPG?
Yes. Select the WebP files, hold right ⌥ and choose Convert › Convert to JPG. Each gets a JPG copy beside it that opens in almost any app or upload form.
Are my images uploaded during conversion?
No. All FileDial tools run on your Mac and files are never uploaded, so unreleased product shots and client images stay with you. Conversion works with Wi‑Fi off.