If the "Multiple Photos" button is missing from your Instagram — don't fret! It's just a glitch. In the meantime, there's an alternative way to post it.

If you find that the button for uploading for adding multiple photos on Instagram has disappeared, don't worry, in this article we will show you how to upload multiple images to Instagram on iPhone, ...

(Alternatively, select multiple images while holding down the Command key.) Finally, choose Image -> Paste Edits from the menu bar to apply the changes to all selected images.