Put the form on paper and let people scan their way in.
Reading a docs.google.com link aloud to thirty people is a waste of everyone's afternoon, and half of them will mistype it anyway. Paste the form link here instead, print the square on the handout, and the form opens in whatever browser the phone already has.
There is nothing special inside this code. A Google Form lives at a web address, and the code carries that address the same way it would carry any other. A camera decodes the string, sees https://, and offers the link. iPhones do this from the Camera app on iOS 11 and later, Android phones from Android 9, and older Android handsets through Google Lens. The form opens in the browser, not in an app, so nobody needs to install anything.
The one detail that matters is which link you copy. Use the address from the Send button, under the link tab, and tick the shortened option Google offers there. That gives you something around 30 characters instead of the 80-plus character /viewform address from the browser bar, and it produces a noticeably sparser code with fatter modules. Do not encode the editing URL. If the address you pasted contains /edit, everyone who scans will land in your form builder.
Leave the white margin alone. The quiet zone is four modules wide on every side, and cropping it is the reason most dead codes are dead. For a handout held in the hand, 2.5 to 3 cm is plenty. For a card on a table people scan while seated, keep it above 3 cm. For a poster read from across a hall at four metres, you need about 40 cm, which usually means the poster wants a short line of text instead.
Dark code on a light background, never inverted, and never printed over a photograph. If you put the school crest in the middle, raise error correction to Q or H. Take the SVG or EPS into the document rather than a small PNG stretched up, and print one proof and scan it before the copier runs off two hundred. Scanning on iPhone is worth checking if your audience skews older, since the camera only offers the link when the code fills a decent part of the frame.
Decide about sign-in before you print, not after. If the form has restricted responses to your organisation, or collects email addresses automatically, anyone outside that account will hit a sign-in wall after scanning, and at a public event that means most people give up. For open feedback, switch that setting off and let people answer anonymously. For a school quiz where you need to know who submitted what, leave it on and warn people that they will need their school login.
Then think about the end of the form. Forms close. A term ends, an event finishes, a defect sheet is replaced by a new revision, and the printed code keeps sending people to a page that says the form is no longer accepting responses. If the paper is disposable, that is fine and a static code is the simpler choice. If the sheet is laminated and pinned to a wall for years, use an editable code: the code on the wall stays the same and you repoint it at this season's form, with a count by day showing whether the bench is actually using it.
The one behind the Send button, on the link tab, with the shorten option ticked. It is around 30 characters and gives a much cleaner code than the long address in the browser bar. Never use a link containing /edit, because that opens your form builder to whoever scans it.
Only if the form requires one. If you have limited responses to your organisation or turned on automatic email collection, a scan leads to a sign-in screen. Switch both off for public feedback, and leave them on when you need to know exactly who submitted each response.
The code still works, but it opens a page saying the form is closed. For a handout that gets thrown away this does not matter. For a code printed on something long lived, use an editable code so you can repoint it at the replacement form without reprinting.
Not with a plain code, which sends the phone straight to Google with nothing reporting back. The form responses themselves are your count of submissions. If you want scans as well as submissions, make the code on the dynamic URL page, where the scans are counted for you.
Between 2.5 and 3 cm across for paper held in the hand. The rule of thumb is scan distance divided by ten, so a code on a wall read from two metres needs about 20 cm. Keep the white quiet zone around it in every case.
Yes. The address of a form does not change when you add questions, reword them or change the theme, so the printed code keeps opening the current version. The address only changes if you build a new form, which is when a reprint or an editable code becomes necessary.