# QR code for audience questions: put it on screen and in the room

URL: https://www.asktide.com/blog/qr-code-for-audience-questions

Richard Frantzen, founder of AskTide. Updated 2026-11-04.

A QR code for audience questions is the fastest way to turn a room or a stream into a Q&A: point a phone, type, send. It only works if people can scan it from where they sit, see it long enough, and have a backup when the camera won't focus. Here are the numbers and the routine that make it work.

**Short answer:** Size a QR code for audience questions so its side is at least one tenth of the scanning distance, use dark modules on a light background with a clear margin, and show it full screen for about 20 to 30 seconds when you open Q&A, then as a lower third at intervals. Always say a short URL out loud for people who can't scan.

## How big should a QR code for audience questions be?

The working rule is 10:1: the scanning distance should be about ten times the code's side. Scanova puts it as "the ratio of the scanning distance to the size of the QR Code should be close to 10:1", so a code scanned from 1 metre should be at least 10 cm wide ([Scanova](https://scanova.io/blog/minimum-qr-code-size/)). QR Code Generator gives the same rule of thumb ([QR Code Generator](https://www.qr-code-generator.com/blog/qr-code-design-rules/)). For on-screen use, Scanova also suggests not going below about 115×115 pixels.

On a screen, what matters is the physical size the code ends up at, so convert pixels to centimetres for the screen you actually have. A few worked examples at 1920×1080:

| Where people scan from | Screen | Code needed | On a 1080p output |
| --- | --- | --- | --- |
| Back row at 10 m | Projection 4 m wide (2.25 m tall) | About 1 m | About 480 px tall, so full screen |
| Middle of the room at 5 m | Same projection | About 50 cm | About 240 px, a lower third can work |
| Sofa at 3 m | 55-inch TV (about 68 cm tall) | About 30 cm | About 475 px, so full screen |
| Desk at 50 cm | 14-inch laptop (about 19 cm tall) | About 5 cm | About 285 px |

The takeaway: on a big screen in a big room, a lower-third QR code only reaches the front half. For the back rows, show it full screen or put printed codes on tables, seat backs and the entrance. These are approximate figures; phones vary, and a dense code (a long URL) needs more size than a short one.

## Contrast and margin: why some codes won't scan

> Test the QR code on the actual output, at the actual distance, with two different phones (one iPhone, one Android) during rehearsal. A code that scans on your monitor can fail on a washed-out projector.

- Use dark modules on a light background. QR Code Generator advises against inverted codes, which "are not consistently supported and often fail to scan".
- Keep a quiet zone of about four modules of light, uniform space on all sides. Don't crop the code tight into a graphic box.
- Avoid placing the code directly over moving video or a busy picture. A solid light panel behind it is safer than transparency.
- Watch out for projector washout and stage lighting on LED walls. Test from the back row with the house lights at show level.
- Keep the URL short. A shorter link produces a less dense code that scans from further away.

## How long to show the QR code, and when

People need time to notice the code, unlock a phone, open the camera and focus. In practice that takes 10 to 20 seconds for most of a room, and longer on a stream where viewers have to reach for a second device. These timings are production rules of thumb, not research findings.

- When Q&A opens, show it full screen for 20 to 30 seconds while the host explains what to do: "Scan the code, type your question, no app needed."
- During the session, bring it back as a lower third for 10 to 15 seconds every few minutes, or after each answered question.
- Before a break, show it again so people can send questions while they wait.
- Have the host say it out loud each time. A visual alone gets missed.
- Take it off once Q&A closes, or the room keeps sending questions you can't answer.

## Full screen vs QR code lower third

|  | Full screen | Lower third |
| --- | --- | --- |
| Scannable from | The whole room, and from a TV across a living room | Front half of a large room, laptops and close screens |
| Covers the speaker | Yes, replaces the picture | No, sits at the bottom of the frame |
| Best moment | Opening Q&A, before and after breaks | Reminders during the conversation |
| Risk | Feels like a break if held too long | Too small for the back row, or clashes with name tags |

In AskTide, the QR code to the audience page is shown on the Display output either full screen or as a lower third, so you switch between the two without changing anything in OBS, vMix or the TriCaster. Take speaker name tags off before you show the lower-third version so they don't stack. Setup guides: [OBS](https://www.asktide.com/blog/show-audience-questions-on-screen-obs), [vMix](https://www.asktide.com/blog/vmix-audience-questions), [TriCaster](https://www.asktide.com/blog/tricaster-audience-questions-graphics).

## How to show a QR code on stream

Online viewers have a problem the room doesn't: many of them are watching on the phone they would scan with. They can't scan their own screen. So for a stream, the QR code is only half the solution.

- Put the audience link as clickable text in the stream description, the chat (pinned if your platform allows it) and the event invitation.
- Show a short URL on screen next to the QR code, large enough to read on a phone.
- Keep the QR code for people watching on a TV, a laptop or a big screen in a meeting room.
- If the stream is shown in an office room or a council chamber, the in-room screen is effectively a projection: size it for the back of that room.

## Placement in the room

- Main screen or LED wall: full screen at Q&A opening, lower third for reminders.
- Confidence monitors and side screens: repeat the code so people at the sides of a wide room can scan it.
- Printed: table cards, seat-back cards, the registration desk and the screen in the foyer. Size print with the same 10:1 rule; a table card read at 60 cm needs a code of at least 6 cm.
- Slides: if a presenter uses slides, add the code to the title slide and the final slide, the moments people are already looking at the screen.
- Accessibility: always pair the code with the short URL in text, and let people ask a staff member or use a roaming microphone.

## The short URL backup

Some phones don't scan, some people don't use the camera for links, and some viewers are on the same device as the stream. Give them a URL they can type. The AskTide audience page lives at asktide.com/view/ followed by the session's 8-character ID, which is short enough to read out. If you want something easier to remember, point a link on your own domain, such as yourorg.com/questions, at the audience page and use that in the QR code and on screen.

Because the audience link accepts questions at any time, you can also send it out in advance: in the calendar invite, a newsletter or the registration confirmation. Questions collected before the event land in the same queue as live ones, and the moderator can shortlist the best ones before going on air. The audience needs no app and no account, the name field is optional, and the page switches to Swedish automatically for Swedish browsers.

## QR code checklist for audience questions

1. **Choose the link.** Use the audience page link or your own short redirect to it. Keep it short so the code stays simple.
2. **Size for the farthest seat.** Apply the 10:1 rule to the farthest row or the typical viewing distance for a TV. If the lower third is too small, plan full screen and printed codes.
3. **Check contrast and margin.** Dark on light, a clean margin around the code, no busy video behind it.
4. **Rehearse with two phones.** Scan from the back row and from the side, on the real screen with show lighting.
5. **Script the call to action.** Give the host one sentence to say every time the code appears, including the short URL.
6. **Plan the cues.** Full screen at Q&A opening and around breaks, lower third reminders during the session, off when Q&A closes.
7. **Post the link everywhere.** Stream description, chat, invitations and printed cards, and send it in advance to collect questions early.
8. **Staff the queue.** Have a moderator ready before you show the code: questions start arriving within seconds. See [how to moderate a live Q&A](https://www.asktide.com/blog/how-to-moderate-a-live-qa).

Running a hybrid event? Read [hybrid event Q&A](https://www.asktide.com/blog/hybrid-event-qa) for keeping room and stream questions in one queue, and the [town hall Q&A checklist](https://www.asktide.com/blog/town-hall-qa-checklist) for the full show-day routine.

## Frequently asked questions

### How big should a QR code be on a projector screen?

Make the code's side about one tenth of the distance to the farthest seat you want to reach: roughly 1 m for a back row at 10 m. On a typical projection that means showing it full screen.

### How long should I show a QR code on screen?

Show it full screen for about 20 to 30 seconds when you open Q&A, while the host explains it, then bring it back as a lower third for 10 to 15 seconds every few minutes.

### Can viewers scan a QR code on a live stream?

Yes, if they watch on a TV, laptop or room screen and scan with a phone. Viewers watching on their phone can't scan their own screen, so always add a clickable link and a short URL.

### Should a QR code be full screen or a lower third?

Use full screen when you open Q&A and for large rooms, and a lower third for reminders when people are closer to the screen. In AskTide you switch between the two on the same output.

### Can people send questions before the event?

Yes. The AskTide audience link accepts questions at any time, so you can share it in invitations and the moderator can shortlist questions before going live.

### Do audience members need an app to scan the QR code?

No. The phone's camera opens the audience page in the browser, with no app and no account needed.