When to use it
Product manuals, safety data sheets, price lists, event programmes, exhibition catalogues, anything that already exists as a designed document and does not need to be rebuilt as a web page. A PDF code is a URL code with a file at the end, so everything about URL codes applies.
How it behaves on phones
iPhone: the Camera app shows the domain in a banner. Tapping it opens Safari, which downloads the file and shows it in its built in PDF viewer with pinch to zoom, a share button and the option to save to Files or Books.
Android: most Android scanners open the link in Chrome, which shows the PDF inline on recent versions. Other browsers, and older phones, download the file to the Downloads folder and the person opens it from the notification. Either way it works, but the second path is slower and confuses some people.
Common mistake
Linking to a 15 MB print ready brochure. On a phone on mobile data it takes half a minute to appear, if the person waits that long. Export a screen version at 150 dpi with images compressed, and aim for under 2 MB.
Gotchas
File size. Print PDFs carry 300 dpi images and embedded fonts. Save a copy for screen: 150 dpi, JPEG images at 80 percent, fonts subsetted. A 40 page catalogue can drop from 30 MB to 3 MB.
Page size. An A4 page on a 6 cm wide screen is unreadable without zooming, and each zoom means sideways scrolling. If you must use a PDF, consider a narrow layout at A5 or a single column.
Hosting and permanence. The link is printed. If the file is renamed, moved or the sharing link expires, the code breaks. Host it on your own domain at a path you will keep, or use a dynamic code so you can repoint it.
Cloud share links. A Google Drive share link is around 90 characters and shows a preview page with a download button rather than the document. A short path on your own site is 40 characters and opens straight away.
Why a web page usually wins. A page reflows to the screen, loads in pieces, is searchable, works with screen readers and can be updated in a minute. For menus, event details and anything people read standing up, a page beats a PDF every time. Save the PDF for documents people want to keep or print.
Try it in QR Studio
QR Studio makes URL codes with a logo and custom colours, and dynamic codes you can repoint at a new file later without reprinting.
Print advice
Level M, Q if the code carries a logo. Manuals and data sheets are scanned up close, so 2.5 cm is fine. On a poster or display board make it 5 cm or more. Print the file’s title and “PDF, 1.8 MB” beside the code so people on mobile data know what they are about to open.
Try it yourself
Enter how far away people will be when they scan and get the minimum print size.