Put a caption on a picture

Because Impact belongs to Microsoft and this page has no right to send you a copy of it, and most phones do not have it installed. A page that simply names it in a stylesheet gets whatever the device decides to use instead, silently - so the preview and the download disagree on the majority of devices that visit. This uses a typeface every platform is guaranteed to have, which means what you see here is what you get.

Because a bar covers the picture and an outline covers almost nothing. A caption has to stay readable wherever it lands, and white text alone disappears over a bright sky while black text disappears over a shadow. A dark edge around light letters works over both, which is why every caption drawn over a photograph - a meme, a film subtitle, a news chyron - is drawn this way.

Not on this page, and that is the point of it: two fields, no dragging, done in a few seconds. The annotation tool takes text anywhere on the image, at any size, with a background or an outline, along with arrows, boxes and highlights - it is the same renderer underneath, with the placement left to you.

No. The preview on screen is scaled down to fit the page, but the download is produced by drawing the words onto the picture at its own resolution - so a caption on a 4000-pixel photograph is rendered at 4000 pixels, not enlarged from the preview. That is also why the size control is a percentage rather than a pixel value.

It is decoded and re-encoded once, in the format it arrived in, at a high quality setting. For a PNG that is lossless and the untouched parts of the picture come back identical. For a JPEG it is one additional lossy generation, which at this quality is not usually visible - and is unavoidable for any tool that draws something onto a JPEG and hands you a JPEG back.

No. The picture is decoded, captioned and re-encoded by your own browser, so it never leaves your device - which matters more here than it sounds, because the pictures people caption are usually photographs of their own friends and family. A content security policy the browser enforces stops this page sending anything to another domain.