Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When I download a file, Firefox removes the file extension. I mean, if I download "something.pdf", it saves the file as "something". I didn't have this problem before yesterday.

Any help would be appreciated...

Edit: But I can open them by right click and open with. Only problem is the file name. I barely used my home pc in last two days and I'm really curious about what happened. I tried to reset everything revelant to downloading and file extensions in "about:config". But no difference...

share|improve this question
Did you check that the folder you're saving the file into is not configured to hide file extensions? – Justin Pearce Dec 28 '12 at 19:24
your files extensions removed or just not shown?? – Arash Dec 28 '12 at 19:32
@JustinPearce: Good question, although that option is not folder-specific. – Karan Dec 28 '12 at 19:43
if you double click the file and it opens correctly, then "Hide Extensions" is enabled. – Chris Nava Dec 28 '12 at 19:50
Of course they're removed. And when I rename them and add the file extension, they open correctly... – s.alem Dec 28 '12 at 20:03
up vote 1 down vote accepted

Save all your bookmarks, passwords, etc.

Then, try the following:

enter image description here enter image description here

share|improve this answer
The most radical solution and worked. Thanks a lot. But I wish I could know why that happened... – s.alem Jan 1 '13 at 0:06

Not enough rep to post a comment, apologies. It might not have to do with you or your browser. The website might have just posted an update that now forgets to put the extension on the item. This happens a lot more then people realize with bad testing or no testing. Can you replicate the issue on another computer. If you can replicate it on another computer, I would send a note to the owner of the site.

share|improve this answer
It's not about the website, because i've already tried differents websites. I can't replicate the problem, because I have no idea what's wrong... – s.alem Dec 28 '12 at 22:22

Issue; Saving with the pre-defiined name works OK i.e save extension But changing the name during save process prompts message that no extension and you can force original extension name.


Open Folder Options. Click View Tab Untick 'Hide extensions for known file types' (which is the default setting for some reason) and now you see extension when changing name.

May not be the same isssue exactly but I laned here when trying to resolve it.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.