A text QR code carries words rather than a link. Scanners simply display the message, which makes it ideal for equipment serial numbers, storage labels, care instructions, exhibition notes, event passwords or a short greeting on packaging. There is nothing to click and nothing to load, so it works even when the phone has no signal at all. Type your message, keep an eye on how dense the pattern becomes, and download a PNG at the size you plan to print.
Thousands of characters in theory, but anything over a short paragraph becomes hard to scan in print. Keep it brief.
No. It is only visible to whoever scans the code.
Yes, line breaks are preserved and most scanners display them.