What is the fastest way to open an excel file from a web page?

Backstory:

In the past users have complained about how long it takes to generate an excel file export. I fixed the speed problem. In fact, exports are so fast that I can afford to create a temporary xls file during every page load with along with a corresponding link. (The files are cleaned after two hours - the load is light enough for the temp files not to create an issue).

What this means is that the user now sees a "click here to export" button that links straight to an xls file.

Issue:

The problem is that if the user clicks the file they still have to wait for excel to open. This can take a good ten to fifteen seconds and the users may confuse this to the site itself still being slow. What I'm look开发者_如何学编程ing for is a way to make it clear that the remaining wait is caused by excel and not by the site. I'm thinking the best way is to instruct the user to "right click and save as" the link, but it's still possible a user can ignore these instructions, left click the link, see excel takes ten seconds to long to load, and think that the site is unacceptably slow.

Question

What's the best way to present the xls file to the user so that it's clear the site has done its job and all the remaining work is on downloading the file and waiting for their own applications to load?

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You can try to force the user to download the xls file instead of the default opening operation of the browser itself.

Force File Downloads instead of opening, PHP tutorial