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  3. Cards not scanning? Fix Classroom Mode problems

Cards not scanning? Fix Classroom Mode problems

What to do when your phone won’t connect, cards won’t read, the camera phone drops out, or the page reloads mid-lesson.

Updated October 16th, 2026

Cards aren’t reading

Check the distance first. Classroom cards read from up to about 4 m, and Large room cards from up to about 7 m. If students sit further back, reprint with the larger Card size.

Cards must be printed at 100%, with the white border kept around each black square. Glossy laminate reflects the lights into the camera, so use matte or none. Sweep the phone slowly and hold on each card until it’s captured.

Your phone won’t connect

On your phone, open quizzy.earth/study/classroom, choose Camera, and type the six letters the projector shows. If the phone says “No screen is showing that code”, check the letters against the projector and type them again. If that still fails, reload the page on the projector computer.

Before the lesson starts, you can also click New code on the projector computer and type the new letters on your phone. If your phone says “The lesson ended on the screen”, type the new code the projector is showing.

The camera phone dropped out

If the projector stops hearing from your phone, it shows Camera phone lost in the corner, with a QR code and a code. If the phone reports a low battery, the same card appears early, with its battery level. Scan the QR code with another phone. Or open quizzy.earth/study/classroom on it, choose Camera, and type the code. Then carry on.

Count the room by eye

No phone to hand? On the projector computer, click Record answers, then Count by eye. Ask everyone to hold up their card, count each letter, and click Use this count. A counted question records class totals, not each student’s answer, and nobody is marked wrong.

Type or tap answers instead

On the projector computer, click Record answers. On the Students tab, type a card number and letter, like 12A, then press Enter.

On your phone, tap Tap instead to turn the camera off and see the class list. Tap a name, then the letter at the top of the card they’re holding. Tap Use the camera to scan again. If the phone says camera access was refused, allow it in the browser settings.

The page reloaded mid-lesson

Open quizzy.earth/study/classroom again in the same browser on the projector computer. The lesson picks up where it was, with the same code. If your phone’s page reloads, it joins the same screen again on its own.

With a saved class, results are saved to your account after each question. If a question says it’s “not saved yet — retrying”, Quizzy keeps trying in the background. If saving still fails, the results screen offers Retry and Keep on this laptop only.

A read was lost on the way

If your phone lists a student as “not counted: lost on the way, please re-scan”, ask that student to hold up their card again and scan it, as long as the question is still open. If it says “closed before it arrived”, the read came after you tapped Done. Tap Dismiss to clear a line.

The count includes students who are away

Before you click Start the quiz, click each missing student in the room list so they show Absent. Absent students aren’t counted, so the phone waits only for the students who are there.

Open Classroom Mode

Related articles

  • Print answer cards for a class
  • Run a lesson with printed cards

More in Teaching

  • Add students and save a class
  • Exit tickets and quick checks with survey mode
  • Get a report of your class’s answers
  • Quiz a class without student phones
  • Set a quiz as homework with a link
  • Show an explanation after each question
Help topics

On this page

  • Cards aren’t reading
  • Your phone won’t connect
  • The camera phone dropped out
  • Count the room by eye
  • Type or tap answers instead
  • The page reloaded mid-lesson
  • A read was lost on the way
  • The count includes students who are away