Reels or the feed
Reels and Stories fill a phone screen, so 9:16 is the shape for them. A feed post shows larger in portrait than in square, which is why 4:5 is there. The card is laid out fresh for every format, so the text never gets cropped off the edge.
The example on this page is 4:5: a short post, the violet background and the dark card.
Timing for Instagram
The length is the typing time plus the hold at the end. For a feed video, a slightly longer hold gives people time to read the whole post once it has finished typing. The preview shows the total length before you export.
Credit and rights
Only share posts you have the right to use: your own, or ones the author has cleared. Hand typed cards carry a small Recreated label and never show a verified tick.
Ready? Open the X tool with this example loaded, or read the other guides.