Annotate an image

A plain screenshot leaves the reader hunting for the part that matters. Annotation shows them where to look: an arrow to the button, a box round the setting, a highlight over the line of text. There are six tools: Arrow, Box, Highlight, Line, Text and Step. Step drops numbered circles, 1, 2, 3, in the order you click, which turns a single screenshot into a short set of instructions.

Fewer marks usually read more clearly. One colour for everything works better than several. Red is the default because it stands out on most screens; switch to blue or black if the design itself is red or orange. Boxes are outlines, so what's inside stays readable, and Highlight is a see-through wash like a marker pen. Text labels sit on a block of your colour, with black or white lettering chosen automatically so they're easy to read.

The Size slider sets the line thickness, and text and steps grow with it. It's measured against the image rather than in fixed pixels, so a mark looks the same weight on a small crop as on a 4K capture. If the screenshot will be seen small, in a chat or on a phone, move the slider up a notch or two. Keep labels to a few words; a full sentence belongs in the text around the image.

A highlight doesn't hide anything. If a screenshot shows an email address, a password or someone's details, black it out with the redaction tool before you share it. You can load several screenshots and mark each one separately: tap a file name to switch, and each keeps its own marks, with Undo working on the one you're viewing. The image keeps its original size, and PNG keeps thin lines and text crisp.