Why are my PNG backgrounds not transparent when I upload them to Dropbox?

[Molly m.4]

I had several files (mostly logos) that had a transparent background and they all have white solid backgrounds now. I have no clue what happened but it is causing me serious issues. 

[Typeaux]

---

@Mark wrote:
As has been said Dropbox simply cannot edit files, so you may wish to look at how they are being edited and uploaded. What applications are you using for that?

---

If the PNG files are being saved from Photoshop, there are several things going on.  First, if there is a white layer in the backgroung where the layer is turned off in Photoshop, the white layer is still there but not visible.  I'm guessing that while Dropbox doesn't "edit" the file, the layer gets flattened with the visible layer and the resulting file is combined.  Not ALL applications support transparent PNG files unless the file itself is devoid of any "invisible" (there, but layer turned off in Photoshop) layers that might become visible if the application cannot distinguish between a layer that is visible and a layer that is not.  Always advisable to take any invisible layers to the trash.

I use PNGs with drop shadows and bezels all the time in many different applications, and I always remove any non-visible layers.  I have not tried uploading such files to Dropbox (yet) but intend to, to see if removing any extraneous layers helps. 

[rogerpenna]

we are talking about files found on the internet and also personal files.

as far as I know, when saving a PNG file, Photoshop doesn´t save layers. That happens if you save a PSD file.

I mentioned in my previous post: DropBox PREVIEWER can´t show the image with transparency, but not only that, it really changes the file. And when you save FROM THE PREVIEWER, even saving as a PNG, it loses the transparency. Saving directly from the files list, without previewing before, works fine.

[Typeaux]

@rogerpenna   You are absolutely right.  I had it wrong. I just ran through the process of creating a PNG file (from a PSD file) *without* deleting the background layer, and the resulting PNG file shows only a single, flattened layer (it is, however, possible to save JPEG files with layers). 

So the claim is that Dropbox does no editing to the file.  That is different from saying that it can handle displaying images on transparent backgrounds.  Even if we're not talking about things like high-resolution corporate logos requiring transparent backgrounds that are placed on client images (for example), I use smaller images with transparencies for producing custom diagrams and workflows where I want certain elements to "pop" or look three-dimensional, so I have libraries of hundreds of transparent .png files used for this purpose.  They would simply not work with white backgrounds. 

So, I am concerned about this limitation, unless someone has found a solution.  Anyone?  Anyone?

[rogerpenna]

I think the problem is a little bigger than just DropBox not being able to display PNGs with transparent background.

Because when you download the PNG from the Previewer Window, the PNG LOSES the transparency information. Which is why I say that, despite DropBox personnel claiming it does not edit the files, it indeed does.

Otherwise, the previewer would show the PNG with white background, but the moment you downloaded it from the preview window, it would download the file just as it is, with transparent background. But no, the file was modified by DropBox and lost it's transparent background.

Again, this happens when downloading from the Preview window.

If instead of first seeing the image, you directly click to download it, from the files list, it downloads the PNG correctly, with transparency.

[tomboates · Accepted solution]

Dropbox is not editing your files... it is generating a copy of the file that does not include transparency and displaying that as a "preview" of your file to improve load times on their website. 

Dropbox creates the image shown in the center which includes a white background. This means that dragging and dropping this image, or right-clicking and selecting "save image as..." will result in you downloading the Dropbox preview version. HOWEVER, if you use the "Download" button on the top right of the page, you will download the un-edited version of your file.

 

The problem is that while this change may have shaved a fraction of a second off page load time, it seems to have screwed up a lot of people's workflows as a result. I think Dropbox needs to consider changing it back or at least find ways to ensure these common workflows result in the desired outcome.

[apraetor]

@tomboates Thanks for the great explanation of what's going on here. It's correct that attempting to drag-and-drop a cloud-generated preview of your image is not the same thing as the original image. This is true for most file formats, to my understanding: if you're routinely dragging the preview image into Photoshop, etc. then you're actually getting a scaled version, not the original file. It wouldn't be much of a preview feature if you had to wait for a 50 mb PNG to download!

Additionally, when you drag-and-drop the preview image out of your browser, that's not actually a functionality provided by Dropbox. The ability for images embedded in web pages to be dragged out of the window and saved is a Chrome/Firefox feature. Dropbox isn't trying to trick you by letting you drag low-quality copies!

[This thread is now closed by moderators due to inactivity. If you're experiencing a similar behavior, feel free to start a new discussion in the Dropbox Community here.]