Expanding and Shrinking the Canvas
A screenshot rarely has the empty margin you need for callouts, arrows, or a header. Annotate lets you grow the canvas on any edge with a single tap - and shrink it back if you change your mind.
The "+" buttons
When you open an image in the editor, you'll see four small circular "+" buttons just outside each edge of the canvas (top, bottom, leading, trailing).
Tap any "+" to add a slice of empty space on that edge, equal to the original canvas dimension along that axis. Each tap adds another slice, capped at a safe maximum so the canvas can't grow forever.
The "−" buttons
After you've expanded an edge, a matching "−" button appears next to the "+" on that edge. Tap "−" to undo one expansion slice on that edge, one tap at a time.
The "−" button is only visible when there's something to shrink. If you reset that edge back to its original extent, the "−" disappears and only the "+" remains.
Custom pixel amount
A single tap adds (or removes) a preset slice. To add or remove an exact number of pixels instead, press and hold a "+" or "−" button. A small popover opens, pre-filled with the amount a single tap would apply on that edge. Type the pixel count you want (or use the stepper), then tap Apply.
The amount is capped at the remaining headroom on that edge for "+", or at how much you've already expanded for "−", so you can't overshoot.
Fill color
The new canvas area is filled with:
- Transparent for canvases that came from a photo, screenshot, file, or clipboard.
- The background color for blank canvases - whatever color you picked when creating it.
Visual canvas size
The current canvas size (in pixels, including any backdrop padding) is shown as a small label below the canvas. It updates live as you expand or shrink edges, so you always know the export size you're working toward.
First-time tip
The very first time you tap a "+" button, Annotate shows a brief tip explaining what you just did, how to revert it, and that you can press and hold a button for an exact pixel amount. The hint can be reset from Settings → Reset hints if you'd like to see it again.