Guides to marking up a screenshot

Practical answers about the thirty seconds between taking a screenshot and sending it — including the parts where the usual advice is wrong. Written to be useful whether or not you ever install this app.

• How to annotate a screenshot on iPhone

  The whole loop on iPhone and iPad: get the image into an editor, cover what should not travel, point at what matters, crop, and get it back out. Including the two things the built-in Markup will not do for you.

• How to blur sensitive information in a screenshot

  What has to be covered, what almost everyone forgets, and how to cover it so it cannot be read back. Includes the checks for status bars, tab titles, QR codes and file names — the parts that leak after the obvious thing has been hidden.

• Mosaic, blur or a solid block: which to use when redacting

  What each of the three actually does to the pixels, which of them destroys information and which only looks like it does, what the recovery research really shows, and the decision rule that follows from it.

• How to number the steps on a screenshot

  Numbered markers, and why they beat four arrows on the same image. Where to place them, what breaks when you delete one, and how to decide between one image with five numbers and five images with one each.

• How to annotate screenshots on a Mac

  The capture shortcuts worth memorising, the clipboard-first workflow that skips the file entirely, where the built-in Preview and Markup run out, and the extra thing the Mac has: an on-device scan that proposes what to cover.

• How to crop a screenshot for social media

  Which shape each destination actually wants, why cropping a tall phone screenshot to a square usually destroys it, what to do instead, and where the unsafe bands are on a vertical story.

• Why a markup tool should not upload your screenshots

  What a screenshot actually contains, what an upload means in practice and in a contract, why a retention promise is not the same as never holding the file, and the airplane-mode test any reader can run in a minute.

• How to annotate screenshots for bug reports

  What a screenshot in a ticket has to show, why the tight crop so often removes the one thing the engineer needed, how to number reproduction steps, and what to redact before it goes into a tracker that keeps things forever.