How to permanently allow opening .webp files in Photoshop on macOS Sequoia 15.4?

FWIW macOS Sequoia 15.6 seems to have fixed this at least for .xmp sidecars exported from Photos (I occasionally edit and fix nonstandard .xmp exported from Photos when joining it to images and movies). BBEdit 15.5.2 now opens such .xmp via the Finder with no alerts.

https://exiftool.org/forum/index.php?topic=12634.msg68327#msg68327

On the other hand, in Sequoia 15.5 BBEdit 15.5.2 still refuses to open such .xmp via Finder if BBEdit is set as the default for .xmp so a possible Gatekeeper update does not seem to explain this. But now I tested what happens if I set Photos as the default for .xmp: Then when .xmp is dropped on BBEdit on the Dock, BBEdit no longer refuses to open it but instead just asks if I want to open such Photos related .xmp, and then opens it.

So after a bunch of testing, it's basically a "bad file association leads to gatekeeper panic" problem.

Apple have changed something, and it has broken how Adobe Photoshop (and GIMP) file association works, which means it triggers a gatekeeper alert if the file is associated with Photoshop (or GIMP), even if you try "open with" and another app.

Apple and Adobe both need to fix things. I have told Adobe about it. They definitely can do it properly and make it work because they did with Illustrator.

Unsure how to tell Apple, other than here (and suggesting Adobe tell them), and they're a bit "our way or the highway" so don't hold your breath!

Best bet for now as a workaround is to change the file association permanently to Illustrator or Preview and then drag it into PhotoShop or open it from within photoshop by "command + O" or the file > open menu. it's a **** workaround but them's the breaks.

So open finder info on a webp (same for avif) file, set the open with to "Adobe Illustrator" (or "Preview" if you don't have AI) and click "change all" button.

Now the webp (or avif) file won't trigger a gatekeeper panic when opened. Then you can open it in Preview or Illustrator or Photoshop or whatever opens webp. I know the "open with.." finder option makes you root through a directory dialogue for photoshop, hence the advice to drag it in or open it from within photoshop.

Directly double clicking a .webp will cause a security message but if I open from Photoshop it loads without error.

Cheers

I don't necessarily want to disable security provisions using terminal so I didn't try that. But it does work if you open the file from Photoshop File -> Open. Not ideal but easier than going to the security panel for every freakin' file.

I have noticed that it only happens on webp files that come via email. My other webp files that I've saved on my computer open fine with a double-click.

Would also be nice if there's a way to take off that mail icon on the file name of files copied from email as well. Wonder if that being there has something to do with why it won't open.

[Edited by Moderator]

Solution:

Drag all WEBP images into Apple Photo App... Select them all.

go to FILE > Export "x" Photos

It will ask you file format and quality, then next will ask for the location.

Done!!!

[Edited by Moderator]

Mr.Snak wrote:

Hmm. Never worked with Preview for me, or anything else. I can only drag and drop into an open Photoshop file.

Sequoia 15.5

Where are you getting the WebP files from? The only limitation I see with Preview is, you can't export an image from Preview to the WebP format.

Hmm. Never worked with Preview for me, or anything else. I can only drag and drop into an open Photoshop file.

Sequoia 15.5

etresoft wrote:

Webp works perfectly fine here, using Preview or any other app.

+½ Most other apps.

Whistling Cat wrote:

This is *not* an Adobe issue, it's an Apple issue -- Preview has the same problem opening webp that Photoshop does.

Webp works perfectly fine here, using Preview or any other app.

I don't have any Adobe apps. But then I have been known to write apps in a few minutes that Adobe says are impossible.

Just to add, I can drag a WebP file into an empty tab in Brave, Firefox and Safari and they will open. I don't have Chrome installed.

Whistling Cat wrote:

I am curious how you can make that conclusion?

Because I can open them in Preview with all my Macs running Sequoia 15.5. I seriously doubt I have the only three Macs that can.

"In any case, if Preview won't open them it has nothing to do with Sequoia 15.5".

Given that's the only thing that has changed on this Mac between when webp will/won't open (in Photoshop, Preview, and Chrome), plus attempting to open webp produces a *system* error (look at the error pix people have posted, they say "Apple could not verify...") not an Adobe/google error, I am curious how you can make that conclusion?

Whistling Cat wrote:

And have been opening just fine on my Macbook in Photoshop/Preview until this weekend, when I updated to 15.5...

You hadn't mentioned that before. FWIW, Photoshop Elements 2025 won't open WebP files period. I don't use Photoshop.

In any case, if Preview won't open them it has nothing to do with Sequoia 15.5

Install EtreCheck and post the report. Allow Full Disk Access.

https://etrecheck.com/

Use the Additional Text icon to paste in the report.

See?