Dropbox-hosted PNG image not visible on some devices

[+barefootjeff]

One of my caches GCA3Q55, an image-based puzzle based on RGB values that was published over a year ago and has been fine until now, has suddenly become problematic for some players with the image not showing on their devices. It's fine on my Windows PC and Android phone running the official app, but it apparently doesn't show on iOS phones with either the official app or Cachly.

 

On the cache page I used the following URL to display the image: https://www.dropbox.com/s/fuh608u83qisvxz/GCA3Q55.png?dl=1

 

I can't use the geocaching site to host the image because all uploaded images now get quietly converted to progressive jpeg which destroys the exact RGB values.

 

Any thoughts on this?

[+Smitherington]

It does not show up on any of my apple devices, phone, pad, or computer. 

[+RCH65]

The ?dl=1 option forces the browser to download the element (and save it as a local file) instead of rendering:

 

Use this instead:
 

 https://www.dropbox.com/s/fuh608u83qisvxz/GCA3Q55.png?raw=1

 

However, it's still not 100% because Dropbox doesn't deliver the correct MIME type to the browser (saying: "This is a PNG image").
But I suspect that it's always been that way with Dropbox...

 

Edited April 12, 2024 by RCH65
typo

[+barefootjeff]

28 minutes ago, RCH65 said:

Use this instead:
 

 https://www.dropbox.com/s/fuh608u83qisvxz/GCA3Q55.png?raw=1

 

 

Thanks, I've now done that and it seems to be working.

Edited April 12, 2024 by barefootjeff

[+barefootjeff]

I've since found this Dropbox help page (https://help.dropbox.com/share/force-download) that explains things a bit more and yes, the ?raw=1 does appear to be the correct way to do this.