png's compressed into broken webp's

[adms-hu]

Describe the bug
In most cases my png's can't be converted into webp's. Sometimes it works but usually I get broken pictures which can't be opened. The compression process is fine, I found no errors. Sometimes I have non english characters in my file names but it happens with english only too without any special character.
I have this issue only with webp's.

Software version
2.8.5

Operating System information
Mac OS 15.6.1 (24G90) Seqouia

To Reproduce
Steps to reproduce the behavior:

1. Open a PNG
2. Set the output to webp and tick same folder as input
3. Compress
4. Inspect the exported file

Screenshots

Application Log
[2025-10-08 18:13:57.958][I] ---- Starting application ----
[2025-10-08 18:13:57.964][I] UUID: "686881b0-2ea3-4a2b-ae98-0ab9411da74d"
[2025-10-08 18:13:58.473][I] Starting UI
[2025-10-08 18:13:58.503][I] libpng warning: iCCP: known incorrect sRGB profile
[2025-10-08 18:13:58.525][I] libpng warning: iCCP: known incorrect sRGB profile
[2025-10-08 18:13:59.942][I] Sys info updated successfully
[2025-10-08 18:14:38.718][I] Compression ended successfully.
Total images: 12
Uncompressed size: "2.24 MB"
Compressed size: "686.48 KB"
Elapsed time: 356 ms
[2025-10-08 18:14:39.067][I] Usage report sent successfully
[2025-10-08 18:16:07.876][I] Compression ended successfully.
Total images: 12
Uncompressed size: "2.24 MB"
Compressed size: "422.48 KB"
Elapsed time: 339 ms
[2025-10-08 18:16:08.256][I] Usage report sent successfully
[2025-10-08 18:17:24.328][I] Compression ended successfully.
Total images: 12

Additional context
Add any other context about the problem here.

[Lymphatus]

Do you have an example of PNG that gets corrupted after the compression so I can try reproduce the issue? Thanks!

[adms-hu]

images.zip

Yes, I attached the source and the output. Thanks!

[Lymphatus]

Looks like Windows 11 is able to open the converted WebPs without issues, both in the Photos app and Paint. Photoshop also seems to open them without issues. I assume that the problem is related to macOS. I'll do some testing tomorrow with my Apple devices and report back to you.

[adms-hu]

Thank you! It could be macOS related, however I prepared these files for Webflow CMS and the upload was unsuccessful. Also when I attached the images here, the PNG was fine but the webp was not. That's why I attached a zip instead.

[Lymphatus]

I can confirm that event the latest macOS cannot open it. Even if Windows can, it's probably a red flag anyways so it's worth investigating.
Problem is also only related to the desktop version, while caesiumclt seems unaffected. I can suggest using it as an alternative while I fix the issue on the desktop version. If you need some help on how use it in your workflow, just ask for help in that repo and I'd be glad to help.

[adms-hu]

Thank you! I'm more comfortable with GUI app versions, but I'll be good with the CLI until the next update.

[printdollor]

Hey! Just wanted to share a tool I built that relates to this topic. It's a privacy-first web interface for [Topic, e.g., Image Compression]. It processes everything locally just like this library. Live tool: knothing.com (Free & Open Source stack).