Privacy policy

The short version

• The meter never records, stores or uploads audio.
• On the free tools, class lists, pictures, settings, the Quiet jar and lesson reports stay in your own browser. They never reach our servers.
• With Pro, the class information you choose to sync (class names, students’ first names, charts, groups, jars and lesson summaries) is stored in your account. Audio and pictures never are.
• Payments are handled by Stripe. We never see your card number.
• We use Google Analytics 4 to count visits and see which tools are used, with advertising features off. Cookies are otherwise used only to keep you signed in. No advertising trackers.

Microphone audio

When you press Start, your browser asks whether this page may use the microphone. If you allow it, the page analyses the sound on your device. About twenty times a second the audio is reduced to a single loudness value, and the audio itself is discarded straight away. Audio is never written to disk, never leaves your device and never reaches our servers.

We ask the browser to switch off its automatic volume leveling, noise suppression and echo cancellation, so that a loud room reads as loud. This changes how loudness is measured, not what is collected: nothing is.

Pressing Stop or closing the tab releases the microphone.

Settings stored in your browser

To remember how you like the meter, the page saves these values in your browser’s local storage:

• the scene, strictness, chime setting and alert delay you chose;
• the optional decibel correction from a phone sound meter;
• the quiet baseline measured during calibration, keyed to the microphone ID your browser gives the page;
• light or dark theme.

These values never leave your browser. You can remove them at any time by clearing this site’s data in your browser settings.

Class lists, pictures and lesson data

The seating chart maker, name picker and group generator use a class list that you type or paste. The class name, student names, keep-apart pairs, seating charts, groups and picked names are saved in your browser’s local storage on this computer only. They are not uploaded, synced or shared. Delete class removes them, as does clearing this site’s data.

Pictures you add to the custom meter are cropped and resized in your browser and kept in its own storage (IndexedDB) on this computer. They are never uploaded. Remove all deletes them.

The Quiet jar keeps today’s count in local storage and empties at midnight. The lesson report is built from a log kept in memory while the meter runs; it disappears when you close the tab unless you print or save it yourself.

If you install the site as an app, your browser keeps a copy of the pages and images so they work offline. That copy holds no class or personal data.

Accounts and Pro

An account holds your name, email address and either a password (stored only as a secure hash) or the Google account you signed in with. A sign-in cookie keeps you signed in; it is not used for anything else.

When you have Pro, these are stored in your account so they appear on every computer you sign in on: class names, students’ first names and keep-apart pairs, seating charts, groups, picker rounds, Quiet jars, and lesson summaries (start and end time, scene, minutes in each state, alerts, marbles, and a 30-second colour trace). No audio and no pictures.

Payments go through Stripe, which receives your card details and email. We receive whether a payment succeeded, the plan and its renewal date. Stripe’s privacy policy covers what it does with payment data.

We keep account data for as long as you have an account. You can download or delete synced class data from your account page at any time, including after Pro ends, and we delete your account and everything in it when you ask by email.

Who processes data for us

• Cloudflare hosts the site and its database.
• Google (Google Analytics 4) measures visits, as described below.
• Stripe processes payments.
• An email provider sends account emails (sign-in links, password resets, receipts).

We don’t sell personal information or share it for advertising.

Earlier waitlist

If you joined the Pro waitlist before Pro launched, we hold your email address and the page you joined from, only to tell you about Pro. Ask us and we will delete it.

Server logs

Like any website, our hosting provider may keep short-lived request logs (IP address, browser type, time and page requested) to keep the service secure and running. We don’t use these logs to identify people.

Cookies and analytics

We use Google Analytics 4 to understand how the site is used: pages viewed, the browser and rough location (country or city, never an exact address), and a few events such as starting the meter, projecting, shuffling a seating chart or starting checkout. Events never include names, email addresses, class lists or anything the microphone hears. Google signals and advertising personalisation are switched off, and Google Analytics does not store IP addresses. It sets its own first-party cookies (_ga) to tell one visit from the next. It is not loaded on the embedded meter shown on other sites. You can block it with any content blocker, or with Google’s opt-out add-on.

Our own cookie is the sign-in cookie, set only when you sign in. We run no advertising scripts.

Children and schools

The meter and class tools are for teachers, and accounts are for adults. We collect nothing from anyone in the room. On the free tools, student names stay on the teacher’s computer. With Pro, students’ first names and class information that a teacher syncs are held for that teacher only, to provide the service: never sold, never used for advertising, never used to build profiles of students, and deleted when the teacher asks. Teachers should enter only what their school allows; first names or initials are enough. The waitlist is meant for adults. We don’t knowingly collect personal information from children under 13; if you believe a child has submitted an email address, contact us and we will delete it.

Contact

To ask a question, or to have your account, synced data or waitlist email deleted, write to us at hello@classroomnoisemeter.org.