There's a quiet frustration buried in this question, and it's one we recognize. A user on a MacBook Air, running a recent version of Excel, just wants to see whether the file open in front of them is a .csv or an .xlsx. Not through a dropdown menu. Not through File Properties. At a glance, in the title bar, where the name already sits. That request should not feel like a luxury, yet here we are, accepting a workaround that adds friction to a task that happens dozens of times a day.
What makes this worth pausing on is not the technical limitation itself, but what it reveals about how spreadsheet tools still treat the user. The title bar is the one constant visual anchor in a session. It is the first place your eyes go when you switch between two files, especially when you're juggling a raw data file and a formatted workbook side by side. Excel already knows the extension. It is stored in the file's metadata, displayed in Properties, and used by the operating system to determine which app opens it. The information is not hidden because it's hard to surface. It is hidden because the interface assumes you will either remember which file is which or take the extra steps to find out. That assumption puts the burden on the person, not the tool, and it is exactly the kind of small, persistent inefficiency that adds up over a workday.
The user's suggestion is simple: let us see the extension in the title bar, or better yet, let us customize what appears there. That is not a niche request. Anyone who has ever worked with both .csv and .xlsx versions of the same dataset knows the confusion of two windows with nearly identical names, differentiated only by a string of characters your eyes may or may not catch. The fact that this reader has to click, open Properties, and hunt for file type means the tool is making them do the remembering, the checking, and the verifying. That is the opposite of empowering. It is the kind of thing that makes a capable user feel like they are fighting the software instead of working with it.
Our take is straightforward: this should be a setting, not a workaround. Excel already gives users control over what appears in the title bar in other contexts, and extending that control to include the file extension is a low-effort, high-impact change. It would not require rethinking the interface or learning new behavior. It would simply make the tool more honest about what you are looking at, when you are looking at it. For anyone who has ever hovered over a window thumbnail or squinted at a tab, that clarity is not a minor convenience. It is the difference between guessing and knowing. And in data work, knowing matters.