How do I post a photo on Instagram?

To upload a photo or take a new one, first tap at the bottom of the screen:

To upload a photo from your phone's library, tap Library (iPhone) or Gallery (Android) at the bottom of the screen and select the photo you'd like to share.
To take a new photo, tap Photo at the bottom of the screen then tap . You can tap to switch between front and rear-facing cameras and to adjust flash.

Once you've taken or uploaded a photo, you can add effects or filters, a caption and your location before posting. You can also post a video.

Note: You can't take or upload photos from a desktop computer.