I can't come up any idea why this picture cannot be added by uploading from URL. The file size is over 1.6 MB a little bit, so it is much less than the max of 2 MB.

Failed to upload image; the format is not supported

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    Related: meta.stackexchange.com/q/261925/245360 Aug 3, 2015 at 9:13
  • Looks like it was created by some fancy software, in the raw response I see "Adobe Photoshop CS3 Windows", and this format is simply not supported by imgur, which tries to analyze the picture. Aug 3, 2015 at 9:23
  • It still seems a regular JPG to me. @ShadowWizard Aug 3, 2015 at 9:24
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    That error happens inside imgur; as such, I can't tell you what specifically it doesn't like (the error message is fairly generic) - as @ShadowWizard notes: presumably there is an encoding option in use that imgur doesn't like. Options: 1) imgur change their API to allow the format; 2) you re-save the file to tweak the encoding; 2 seems like a more timely fix Aug 3, 2015 at 14:39
  • Agree with @Marc that this probably isn't worth spending much time on, unless we'll see this happening more. Aug 3, 2015 at 14:50
  • @MarcGravell "the issue seems to be on the SE's imgur interface where some kinda URL validation (and/or filename check) is happening before the image upload" - quoted HackerKarma below
    – Ooker
    Aug 3, 2015 at 15:05
  • @Ooker SE's imgur interface from where the API sends the data to imgur... I would like to see what the endpoint respone looks like... we need to look into base64 + url encoding which is causing the wrong interpretation of the final url Aug 3, 2015 at 15:09
  • @Ooker I'll take another look Aug 3, 2015 at 15:09
  • @MarcGravell I agree the response is generic... i know you guys are super busy but please look into the response header .... like I said in the above comment Aug 3, 2015 at 15:10
  • @HackerKarma <error><message>Image format not supported, or image is corrupt.</message>...; I'm checking something, though Aug 3, 2015 at 15:20
  • @HackerKarma your comment isn't clear, but if you work for imgur ("we need to look into", etc), feel free to ping me at [email protected], and we can talk more - but I'm not going to dump the raw http (including keys, etc) here ;p Aug 3, 2015 at 15:27
  • @MarcGravell Appreciated. If that's what imgur sending then they must be striping out all other data like "parameters:, request:, type:, method:, success:.... etc. I think we have to look into the "CONFIG" options that API gets.... base64 encoding ... Aug 3, 2015 at 15:30
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    Let us continue this discussion in chat. Aug 3, 2015 at 15:38
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    To confirm: looks like I am wrong and this is our fault; we should be able to fix it soon Aug 3, 2015 at 15:40
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    @Ooker. No, I am not targeting you either. The official ♦ mod answer and upvotes, as far as my answer goes, and in general. How many of those upvoters do you think read my answer, comments, conversation with Marc. If they did then why am I left with 2 votes (excluding your's). That's why that joke but [status-completed] was my takeaway. But, since I worked so hard for this answer, I felt little sad to see your un-acceptance. And, that was it, nothing against you. You're fine. Comments are getting lengthy so its my last comment. Aug 3, 2015 at 19:36

3 Answers 3


This has something to do with Stack Exchange's imgur upload interface. May be the file resize algorithm (ShadowWizard's comment below), file encoding settings, etc that goes while analyzing the image before the actual upload. I just uploaded the OP's suggested image by visiting to http://www.imgur.com and used "enter image URLs" option to upload the image.

Here is the direct link to uploaded image using "enter image URLs" at imgur:

![Direct link](https://i.sstatic.net/Fj4b2.jpg)

enter image description here

Here is the same above image added by uploading from URL using "SE's imgur interface":

enter image description here

Now, here is some food for thought. Upon doing further investigation on few things such as:

  1. Source site blocking imgur from accessing
  2. Imgur blocking/banning the source site
  3. Invalid image type
  4. URL format of the image without any special chars in it (especially in the "file name")

As far as the first three points goes, there is no issue at all. My first two screenshots voids all those first 3 points. So, the next thing left was to try and upload images from the same source with proper file name.

Here I am uploading http://www.litaniasports.com/images/stadium.jpg using SE's imgur file uploader: (works perfectly!)

enter image description here

Now, I tried another image (from the same source) with a special char %20 i.e. a space in it http://www.litaniasports.com/facility/documents/830901%20Closed.jpg

and it throws the following error: (as said by OP)

Failed to upload image; the format is not supported

So, the problem is not about the file type or its format, it has something to do with the special char i.e. %20 (a space) in the image filename. The special character (%20) in the image filename has no issue when you do a direct web-upload (by entering image URL) on the imgur.com website. So, the issue seems to be on the SE's imgur interface where some kinda URL validation (and/or filename check) is happening before the image upload.

That's what I can think here. Please share your thoughts or any additional findings.

  • 1
    True, that's likely because the resize algorithm that imgur is trying to use on behalf of Stack Exchange, which fails for some reason for that specific picture. Aug 3, 2015 at 10:40

The reason for that is because the .NET Uri class has a distressing habit of not quite retaining what you put into it ;p In the next build, we have circumvented this glitch, and the url you show above now works fine - as do other URLs.

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    you're stealing all my +1's :) No issue... [status-completed] is the biggest upvote for me and my contribution to SE. Aug 3, 2015 at 16:19
  • lol, R.I.P my glorious theory... :-D Aug 3, 2015 at 17:34
  • This is not fair at all... I can understand the votes but un-accepting answer that was right is very demoralizing. I worked hard for this debugging, reading imgur API pages and chatting to Marc Gravell: chat.meta.stackexchange.com/rooms/907/… Aug 3, 2015 at 17:40
  • @ShadowWizard what glorious theory? Aug 3, 2015 at 17:40
  • @HackerKarma that the problem is in imgur's code Aug 3, 2015 at 17:41
  • @HackerKarma why not fair? You should know the risks when answering bug reports. Aug 3, 2015 at 17:44
  • @ShadowWizard I don't get it... To confirm: looks like I am wrong and this is our fault; we should be able to fix it soon – quote Marc Gravell Aug 3, 2015 at 17:44
  • @Hacker imgur is not part of Stack Exchange just provides the image hosting and API (if you got more questions or comments I can help with, please hit me on chat let's not flood poor Marc here :)) Aug 3, 2015 at 17:45
  • @ShadowWizard read my comment above. I will leave this up to Marc to clarify. Aug 3, 2015 at 17:46
  • @HackerKarma: Your answer certainly deserves upvotes, but the accepted answer should be the one that answers the question most clearly and definitively. For bug reports, that usually means an answer from the SE devs saying that they've fixed (or will fix, or will not fix) the bug. Don't take it personally; just enjoy the rep from the upvotes, and live with the fact that the +15 rep from getting accepted is likely temporary. Aug 3, 2015 at 20:32
  • @IlmariKaronen Appreciated. But, in some cases, if you know the API then you can point the bug which in this case was "URL wrapping/encoding/validation". In fact, Marc and I had a chat (after our comments got lengthy) on this. Anyway, no worries. Aug 3, 2015 at 20:47

In all the irony . . .

I just saved the file and uploaded it again. You could do the same yourself.

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    So the URL upload doesn't work. The picture upload does. Aug 3, 2015 at 9:17
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    Yes. Maybe it's an issue with their server. BTW @Patrick is this kinda answer acceptable? I did show the solution/showed more precisely where a possible bug is. . .
    – M.A.R.
    Aug 3, 2015 at 9:18
  • Don't know. In my opinion it should just be fixed. Aug 3, 2015 at 9:20
  • @PatrickHofman It's SE's imgur upload doesn't work. See my answer below Aug 3, 2015 at 10:41
  • @inɒzɘmɒЯ.A.M No, it's not a server issue... please see my answer. Aug 3, 2015 at 10:48

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