PDF extension missing when saving files on MacBook Pro running macOS 15.6

When you have the Save As dialog box open, you need to click the drop down list box that has a bulleted list icon on it. At the bottom of that drop down list box you need to uncheck "Hide Extension".

I don't know if this setting applies to just that one app, or one file type, but usually once unchecked I never have to worry about it for a specific file type within that app anyway. Unfortunately Apple doesn't do a good job designing this interface. If you go to save another file after unchecking that option, you may see it check, but the file will still save with the extension visible (very annoying).

The .pdf extension (and others, .docx, etc.) are there, they are simply hidden by macOS. If you want to see it, you can select the file in Finder, Get Info (Command-I), then untick the Hide extension box.

Typically, when you attach a file to an email or upload it, the extension is there and there’s no need to add it yourself. If you do add it, macOS is smart enough that it doesn’t duplicate the extension.

To exemplify, I used the Print command in Preview to save a file called Test as a pdf. In the Get Info box, you see the file name is actually "Test.pdf" and the extension is hidden. In Finder, the extension does not show up. But when I drag the file to an email in Outlook, you can see the extension there.

FWIW some web pages do not automatically add an extension to the saved item. I guess it depends on how the page was made. So sometimes I must check the correct extension like .avif with xxd via the Terminal or usually more easily with 3rd party apps like exiftool or GraphicConverter (GC can automatically add or fix the correct extension to many image files).

When you “Save as PDF” via Print from most apps, macOS does include the .pdf, it just hides it in Finder.

But with some web apps (like Gmail in Chrome), the download comes through without a clean extension, so Finder doesn’t know what to label it.

Two fixes:

1) in Finder, go to Finder > Settings > Advanced and check “Show all filename extensions” so you always see what’s actually there, and

2) if Chrome is the culprit, try “Download as PDF” directly in Gmail or use Safari/Preview to save, those preserve the extension properly.

That way you’re not stuck renaming files every time.

Sazbow39 wrote:

Chrome and Gmail

Unless you absolutely require Chrome for some reason, I'd completely remove it.

https://chromeisbad.com/

Safari does download files with the extensions intact, including when accessing Gmail in Safari. If you must use Chrome, consider Brave instead (Chrome code without the Google baggage that is installed on your system and runs in the background even if you delete Chrome).

Sazbow39 wrote:

Safari saves to downloads folder without an option to select the folder I need it to go to for easy access later.

Secondary-click (Control-click or two-fingers) then use the Download As or Save As option and you can specify the location. Or Safari menu > Settings > General tab, set your preferred download location.

Sazbow39 wrote:

Thanks, I did find that one previously and it didn't do anything to change it unfortunately.

It does work since I use it all the time. I've never encountered a case where it did not work, except for what I noted in my last post.

Keep in mind there are about three or so different methods in macOS to show & hide a file extension/Finder settings you may have changed in an attempt to "fix" things, nor do I know what third party apps you have installed which could be modifying the normal behavior of macOS. Everything regarding file extensions must be at system defaults for it to work....I cannot say what happens if other aspects of the Finder/system has been modified.

Another high level & respected forum contributor, @etresoft, had a couple of posts in the past year or so explaining the multiple & conflicting options. Unfortunately I don't have a link to their post & don't have the time to do a more thorough search for the posts.

What mail client / browser are you using?