Cards not scanning? Fix Classroom Mode problems

Your phone only shows the camera

That’s expected: a phone opens Classroom Mode as the camera, and the questions show on a second device. Open quizzy.earth/study/classroom on a laptop or desktop and leave it on Display. Then join with your phone: scan the QR code under Camera access, or type the six letters the display shows. To use the device you’re on as the display instead, choose Display under This device is.

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 across the room. Every card in view is read at once, so there’s no need to stop on each one.

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. If the phone says it’s offline, connect it to Wi‑Fi or mobile data, then type the code again.

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.

An in-app browser can’t use the camera

Many apps open links in their own in-app browser instead of your phone’s browser: Zalo, Facebook, Messenger, Instagram, WhatsApp, LINE, TikTok, Telegram, X and others. Most in-app browsers won’t let a website use the camera. The phone names the app it’s in, for example “Zalo’s browser can’t use the camera”. Tap Copy link on the phone, open Safari on an iPhone or Chrome on Android (or your phone’s usual browser), and paste the link into the address bar. The phone joins the same room. You can also use the app’s ⋯ menu and choose to open the page in your browser. To avoid it next time, scan the projector’s QR code with the phone’s own camera app.

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.

The camera picture stopped

Sometimes a phone stops sending the camera picture, for example after the screen locks, another app opens, or you leave full screen. Your phone then says Scanning paused over the picture, with the reason. At first it restarts the picture by itself, so there’s nothing to do. If it can’t, it asks you to tap Restart camera.

If the picture still doesn’t come back, tap Restart camera again: this reopens the camera from scratch. You can also tap Tap instead and record answers by hand until it does.

Count the room by eye

No phone to hand? On the projector computer, click Students & 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.

Fix an answer after tapping Done

While the results for a question are showing, tap a student’s name to change their answer. On your phone, tap the name in the results table. On the projector computer, click Students & answers, then click the name. Pick the letter on their card. The score updates straight away, and the change is saved with the lesson. Once you move to the next question, that question’s answers are final.

Record answers by hand

On the projector computer, click Students & answers. On the Students tab, click the student’s name, then the letter at the top of their card.

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. If it says the camera can’t open on this address, open quizzy.earth on the phone, or tap Tap instead.

Full screen and motion access

The full-screen camera is optional. On Android, it hides the browser bars and turns the screen sideways for you. iPhone doesn’t let websites do either, so the camera fills the page instead and suggests turning your phone sideways.

On iPhone, the first time you tap the full-screen button, Safari asks whether Quizzy may use motion and orientation. We’d be grateful if you allow it. We use it for one thing only: to notice when the camera picture is sideways compared with the room. Each card’s answer depends on which edge is at the top, so a sideways picture would read every card as the wrong letter. When that happens, Quizzy pauses scanning and asks you to turn the phone. Motion readings stay on your phone. They’re never recorded or sent anywhere.

If you’d rather not allow it, that’s completely fine. Full screen and scanning still work. Quizzy just can’t warn you when the picture is sideways. To be safe, turn off rotation lock, and hold the phone so the picture on screen matches the room.

The camera itself also needs your permission. Quizzy uses it only to read the cards, and the video never leaves your phone. If you’d rather not allow it, tap Tap instead and record answers by tapping names (see below).

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 the results say “Saving these results to your account…”, you can still click Done: the laptop keeps trying on its own. If it’s offline, the results say so, and they save once it’s back online. If saving fails, the results screen offers Retry and Keep on this laptop only.

A lesson didn’t save to your account

A lesson you left with Done while it was still saving is listed in the Classroom lobby under “Still saving to your account”. Keep Classroom open on that laptop until the note goes: it keeps trying on its own.

If your account refuses a lesson, the lobby lists it under “Lessons not saved to your account”, with the reason. Its results are only on that laptop. If you were signed out, click Sign in, then Try again. If the class belongs to another account, click Use another account. Dismiss removes the lesson from the list and from the laptop for good. If the reason says trying again won’t change anything, tell us with Send feedback at the top of Classroom.

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 the lesson moved on to the next question. 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.