I know about two times you could expect to see that: (1) restricted sites like Mozilla sites, and (2) sites that protect themselves from extension scripts using the "sandbox" security policy (#2 was fixed in Firefox 128).

Do you want to share some example URLs by sending them to jscher2000@outlook.com or posting in this thread: https://github.com/jscher2000/Save-webP-as-extension/issues/30

I haven't noticed any problem saving a PNG on images I have tested, but I did notice that when the WebP image is huge/complex, the file can be very large and take a long time to generate/save (JPG 6.7 MB vs. PNG 25.5 MB). If you notice any pattern to the problem, could you let me know at jscher2000@outlook.com or start a new issue at https://github.com/jscher2000/Save-webP-as-extension/issues/.

Is the problem on sites where the images zoom within the page? I tried to fix that bug with the version 1.5.2 update. However, I only had one badly behaved site to test on. Could you send me the new problem site(s) at jscher2000@outlook.com or mention them in a new comment under the following issue: https://github.com/jscher2000/Save-webP-as-extension/issues/10

Or maybe it's a new scenario. Any leads would be helpful. Thanks.

Sorry to hear about this problem. Do you want to send me a message at jscher2000@outlook.com for assistance?

This combination of settings will accomplish that:

Save Dialog / AutoSave Options
Show Save As dialog each time => "Yes"

Save Path Options
Initial or Autosave folder => "Directly in my downloads folder"

I need to update the text on the Options page to clarify that.

Thank you for this report. I believe Firefox does have *some* limit on the size of an image it will draw on or extract from an HTML canvas (which is how the conversion is done). Still, 8190 seems too short, since my test image is 720x22000 and that one works fine when I open it stand-alone in a tab.

When you are saving the image in its original page, I wonder whether a style rule can affect the height? Maybe you can send me an example URL of where the problem occurs, either in a new issue at https://github.com/jscher2000/Save-webP-as-extension/issues/ or by email at jscher2000@outlook.com.

Hi, that is strange. There is an open issue related to only getting a quarter of a zoomed product image on at least one site. Maybe it is a related problem? Feel free to add example URLs to the open issue at https://github.com/jscher2000/Save-webP-as-extension/issues/10 (or you can email me at jscher2000@outlook.com if you don't want to create a Github account).

Meanwhile, does it work any better if you open the image in a new tab before trying to convert?

*UPDATE*

Hopefully the next update (1.5.2) will fix this.

If you go to the Options for the add-on (click the "gear" wheel icon on the button bar), "Save Path Options" section, you can change to saving directly in the Downloads folder. Due to limitations on where add-ons can auto-save, I can't offer very much flexibility on this. If you prefer to choose where to save each time, the setting above that lets you select your preferred approach.

For converting to PNG and JPEG, the add-on doesn't need to use external services unless Firefox restricts the page. To convert animated WebP to animated GIF, you need to use an external service (Firefox doesn't have a function add-ons can call for that).

Hi, do you mean the one assigned CVE-2023-4863? Mozilla issued Firefox 117.0.2 and 115.2.1 to address the problem. See: https://www.mozilla.org/security/advisories/mfsa2023-40/

The reason for mentioning that patch is: this extension uses features Firefox makes available to add-ons and web page scripts; the extension does not have its own image conversion libraries.