This is a tool for saving the alt text you've written on Twitter. You'll need an archive of your tweets, read This Guide for how to get one if you haven't yet. Be aware that it can take a day for it to be available for download. Don't worry, this tool will still be here.
First you'll need to agree to let this site read your tweets, then upload your archive. Don't worry, your whole archive won't be sent to us, just the tweet identifiers for your tweets with images. It could take some time to prepare your alt text.