You could try changing the preference marked in bold in this quote from searchfox. org. browser.download.useDownloadDir - bool True - Save files directly to the folder configured via the browser.download.folderList preference. False - Always ask the user where to save a file and default to browser.download.lastDir when displaying a folder picker dialog

Sometimes I do NOT want to save the file to anywhere on the computer, I just want to open it. That's why I don't use Chrome because there is no way to turn off the must save the file before you can look at it.

There is a preference you can change which may reverse the change but it will be temporary. https://support.mozilla.org/en-US/questions/1370494

Firefox will always have to download a file when you open it for viewing. This download was previously saved to the temp folder, but the file is now saved to the default download as set in Settings (Options/Preferences) just like happens with other downloads.

• https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file

In Firefox 97 and 98+ there have been changes to the download panel.

• https://www.mozilla.org/en-US/firefox/98.0/releasenotes/
• https://support.mozilla.org/en-US/kb/manage-downloads-preferences-using-downloads-menu
• https://support.mozilla.org/en-US/kb/where-find-and-manage-downloaded-files-firefox

You can set this pref to false on the about:config page to prevent opening the download panel on each download.

• browser.download.alwaysOpenPanel = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox