About this tool
A free, browser-based classroom traffic light. Project it at the front of the room and the class sees one big, color-coded signal — green, amber, or red — that you set by clicking. It is the visual half of "settle down" without the raised voice: change the light and the room reads it from the back row.
Unlike a noise meter, the traffic light does not measure anything. It needs no microphone, no camera, and no permissions of any kind. There are no network requests once the page has loaded — the tool is a small HTML, CSS, and JavaScript file that runs entirely on your device, which makes it about as private as a web tool can be. There is simply nothing to send anywhere.
There is no account to create, no upgrade tier, and no advertising. Use it every day or once a term — it is the same free tool either way.
How to use it on a projector or smartboard
- Open the page on your classroom browser on the projector display.
- Click Full screen. The traffic light expands to fill the display so it is readable from anywhere in the room.
- Click a light — green, amber, or red — to set the signal. Click another to change it. The big label underneath updates to match.
- Rename the lights in the Labels & descriptions panel to fit your room — for example Silent / Whisper / Talk, or On task / Warning / Stop.
- Optionally add a short description under any light — a sentence like "Independent work, voices off" — and it shows as a subtitle under the big label, on the projector and in full screen. Leave it blank to keep just the label.
- To exit, press Esc or click Exit full screen.
Your labels, descriptions, the caption toggle, and the current color are all stored in your browser's local storage, so the next time you open the page everything is exactly where you left it. (Closing the tab keeps them; clearing site data wipes them.)
Ways to use a classroom traffic light
A traffic light is deliberately simple — three states everyone already understands. That simplicity is what makes it work across grade levels and activities. A few common uses:
- Voice level. Green for full discussion volume, amber for partner whispers, red for silent work. The light sets the expectation before the activity starts, so you are not refereeing volume the whole time.
- Work mode. Green means "you may move and collaborate," amber means "wrap up and return to seats," red means "eyes front, listening." A single click signals a transition without you talking over the room.
- Question and help signals. Green means "I am available for questions," red means "I am working with a small group — try three-before-me first." Students check the light instead of interrupting.
- Pacing a timed task. Pair the light with a countdown timer: green while there is plenty of time, amber as a two-minute warning, red when it is time to stop and submit.
Because the labels are editable, the same tool covers all of these — you are not locked into "Stop / Get ready / Go." Pick the words your room already uses and the light becomes a faster version of a routine you have probably already taught.
Traffic light vs. noise meter
These two projector tools look similar and solve adjacent problems, but they work in opposite directions. The Classroom Noise Meter is automatic — it reads room volume through the microphone and changes color on its own as the class gets louder or quieter. The traffic light is manual — it shows whatever signal you choose, regardless of how loud the room is, and it never listens to anything.
That difference matters in practice. A noise meter is the right tool when you want the room to self-regulate against its own volume in real time. A traffic light is the right tool when the signal is a decision you are making — "we are moving to silent work now," or "I am with a reading group, hold your questions" — that has nothing to do with the current noise level. Plenty of classrooms keep both projected: the meter as an ambient volume gauge, the light as a deliberate, teacher-set cue. If you want the automatic version, the noise meter is one click away; if you want full control and zero permissions, this is it.
Free, no signup, nothing leaves your device
This page is a deliberately small alternative to all-in-one classroom dashboards that bundle a traffic light behind a signup. There is nothing wrong with those products; they are just not what this is. This is one tool, free, no account, no campus license required.
And because the traffic light is set by hand, it collects nothing — no microphone access, no camera, no analytics, no telemetry, no outbound requests of any kind. A district IT reviewer can confirm it in the Network tab in seconds: there is no traffic to inspect. The source is small enough to read in a few minutes.
Need other free classroom utilities with the same privacy stance? Browse the teacher tools collection — name picker, timer, noise meter, group generator, attendance sheet, grader, and more. Or open the full tools index for the whole list.
Frequently asked questions
How do I change the light?
Click any of the three lights to switch the signal to that color. You can also use the arrow keys to cycle through them once a light is focused. The change is instant and the big label underneath updates to match. Whichever signal you leave it on is remembered, so reopening the page brings back the same color.
Can I rename the lights?
Yes. Each light has an editable label in the panel below — the defaults are Stop, Get ready, and Go, but you can change them to anything your room uses, such as Silent / Whisper / Talk, or On task / Warning / Stop. The labels are kept in your browser so they are there the next time you open the tool.
Can I add a description under each light?
Yes. Each light has an optional description field in the panel below. Type a short sentence — for example "Independent work, voices off" under red — and it appears as a smaller subtitle beneath the big label whenever that light is active, including in full screen. Leave the field blank and no subtitle shows, so you only see extra text where you actually want it. Descriptions are saved in your browser along with the labels.
Does it use my microphone or camera?
No. The traffic light is purely a visual signal you control by clicking — it never requests the microphone, camera, or any other permission, and it makes no network requests at all. It is one of the most private tools on the site: there is simply nothing to send anywhere.
Will it work on a projector or smartboard?
Yes — that is the design target. Click Full screen and the traffic light fills the display so it is readable from the back of the classroom. Press Esc or click Exit full screen to return. Because the whole tool runs in the browser, it works on any projector connected to a laptop, smartboard, or classroom computer.
Is it free?
Yes. Completely free, no account, no signup, no ads, no upsell. The whole tool is a small HTML, CSS, and JavaScript page that runs on your device. Use it every day for a school year or once and never again — same price either way.
How is this different from a classroom noise meter?
A noise meter measures room volume with the microphone and changes color on its own; a traffic light is set by you, by hand, to signal whatever you want — voice level, work mode, transitions, or behavior. Many teachers use both: the noise meter for an automatic volume cue and the traffic light for a deliberate, teacher-controlled signal.