Hi tlk23, could you describe the problem in more detail: is Firefox forcing you to download the file, or is Firefox not able to download the file? Also, this article describes how to set your preference for PDF downloads -- in order to view a PDF in a tab, use the first choice, "Open in Firefox": [[View PDF files in Firefox or choose another viewer]] However, there are some ways that servers can bypass viewing in a tab, so that doesn't work everywhere and in those cases, you might need to use a workaround (more details if relevant).