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HTML files' extension changed during download

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  • 2 have this problem
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  • Last reply by cor-el

JHSACHS
JHSACHS
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I'm using Firefox 126.0.1 (64-bit) in Windows 11. I needed to download two files named index.html (in different source directories) from my company's content management system. Both got downloaded as index.htm. They were the right files... only the extension was changed.

I spoke to the person who maintains the content management system. They tested it and said it's not doing that, must be the browser.

That sounds fantastic to me, but I looked through the support messages here and found several about files whose extensions were changed on download; for example from .loa to .mp3. No explanations or workarounds, though.

Can anyone shed light on this?

I'm using Firefox 126.0.1 (64-bit) in Windows 11. I needed to download two files named index.html (in different source directories) from my company's content management system. Both got downloaded as index.htm. They were the right files... only the extension was changed. I spoke to the person who maintains the content management system. They tested it and said it's not doing that, must be the browser. That sounds fantastic to me, but I looked through the support messages here and found several about files whose extensions were changed on download; for example from .loa to .mp3. No explanations or workarounds, though. Can anyone shed light on this?

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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You can check handlers.json in the Firefox profile folder to se if there is a reference to the .html file extension.

You can check specific file extension keys (e.g. .html) in the registry with the registry editor.

  • HKEY_CLASSES_ROOT\.xxx

You can check possibly linked MIME types in the MIME Database registry key.

  • HKEY_CLASSES_ROOT\MIME\Database\Content Type\

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