Privacy policy

Last updated October 22, 2026

Who we are

ClassDa.sh (“we”, “us”) is the website at classda.sh, a free classroom display and homeroom manager for K–6 teachers. It is run independently by one person, David. Questions about this policy go to david@classda.sh.

How ClassDa.sh is meant to be used

A teacher runs ClassDa.sh on a classroom computer and shows it on the board. Students see the board and may tap it, but they never have accounts, never sign in, and are not meant to use ClassDa.sh on their own devices.

What's stored on your device, and only there

Everything you put into ClassDa.sh is saved in your browser's own storage (IndexedDB) on that computer. That includes:

• the class list: first names or nicknames, last names if you add them (optional, for your reports; never shown on the board), an optional pronunciation note, birthday (month and day only, never a year), animal and colour, and class job;
• points and the reason given for any minus point, the class goal and table points;
• attendance marks (absent and late), bathroom trips, and times out of class with the reason;
• your school year, bell schedules, lunch menu, learning targets, lessons, notes, slides and slide pictures, and sub plans;
• saved drawings, and any songs or videos you add for Music or Freeze Dance;
• your settings, links, and the town you chose for the weather (and the latest forecast for it).

None of it is sent to us or to anyone else. We ask the browser to keep this storage “persistent” so it isn't cleared to save space. A child's age is never asked for or shown. A −1 and its reason are never shown on the board; they appear only in the records you export.

Use only what you need. First names or nicknames are plenty; last names are optional, so leave them out if your school prefers. Please don't type sensitive details (health, discipline records, family matters) into notes, and follow your school's rules about what may be kept on a classroom computer.

Erasing it

• Settings → Classroom setup → Class list → Erase and start over erases your class, its records, your settings and your slide pictures from that browser.
• Clearing the site data for classda.sh in your browser's settings removes everything, including the copy of the app kept for offline use.
• On a shared computer, use a separate browser profile for your class, and erase it when you leave the room for good.

The classroom file

Settings can save a .classdash file: a backup of your whole classroom, made inside your browser and saved wherever you choose. If you add a passphrase, the file is locked with AES-256 encryption before it's saved, and nothing in it is readable without that passphrase. We never receive these files and can't open them, so we can't recover a lost passphrase. Treat the file like any other class record and keep it where your school allows.

In Chrome and Edge you can also have the board save a classroom file to a folder you pick, once a day. The browser asks you to allow that folder; the file goes only there, on your computer or your school drive.

Present mode

Present opens a second window for the board on the same computer. The two windows keep in step through the browser itself (a BroadcastChannel); nothing travels over the network.

The teacher lock

You can set a PIN so reports, minus points, private notes and deleting things ask for it first. The PIN is kept on this device only, as a scrambled hash (never the digits), and it never goes into a classroom file.

The microphone

The noise meter asks the browser for the microphone and turns what it hears into a single loudness level, many times a second, on your device. Nothing is recorded, saved or sent. It stops listening when you close the meter (or turn off the traffic light, which uses it too), and the browser shows whenever the microphone is in use.

The camera

The Doc cam asks the browser for a camera (a document camera, a webcam or a phone used as one) and shows its picture on the board. The picture goes from the camera to the screen on your device, and to the board window if you use Present, and nowhere else. Nothing is recorded or sent. The camera turns off when you close the Doc cam. A frozen picture is kept only if you save it: as a file on your computer, as a slide, or as a saved drawing, all of which stay on your device (slides also travel in a classroom file you make).

Show a tab works the same way: the browser asks which tab to share (every time) and shows that it's sharing. The tab's live picture and sound go to the board on your device, and to the board window if you use Present, and nowhere else. Nothing is recorded or sent, and sharing stops when you close it or press the browser's Stop sharing.

Sites opened over the board

A link that can't play inside the board opens in its own browser window placed over the board (or in a new tab). It's an ordinary visit to that site, under its own privacy policy, as if you'd typed the address yourself. The board keeps hold of that window only to bring it back to the front and close it; the site can't reach back into the board.

The few things that use the internet

The National Weather Service is part of the US government (NOAA); see its privacy policy. We never send it, or anyone, a student's name or anything from your class.

The board makes no other connections. Fonts, sounds and drawings are part of the app. Every page is served with a Content Security Policy that tells the browser to refuse connections to anywhere other than our own site and the weather address above, and to show another site inside the board only from the players listed above, so this list is enforced by your browser, not just promised. Each player is fenced off from the board: it can't read your class, move the board's page somewhere else or put a box over it. ClassDa.sh does not call any AI service. The optional AI shortcuts give you a prompt to paste into an AI chat you choose, to turn files you already have (a class list, the school calendar, bell schedules, the lunch menu, a seating chart, groups, a lesson and the like) into something the board can read. The answer you paste back is checked on your device. Some of them work with your students' names, because that's the job. What you share with that AI is between you and it, under its own policies: use one your school has approved and follow your district's rules.

Information our hosting provider receives

ClassDa.sh is hosted by Vercel Inc. When a browser loads a page, Vercel's servers automatically receive standard technical information: the network's IP address (usually the school's), the browser type and the page requested. Vercel uses this to deliver the site and protect it from abuse, and keeps it for a limited time under its own privacy policy. We don't use it to identify anyone.

We also count visits to the front page, the demo and these site pages with Vercel Web Analytics, so we know how many people find ClassDa.sh and which pages they read. It sets no cookies, keeps no identifier that follows a visitor from one day to the next or from site to site, and shows us only totals. The board (/live), where your class lives, is never counted, and nothing about your class is ever part of a count. Blocking it (an ad blocker or a school filter) changes nothing else.

Children's privacy (COPPA) and student records (FERPA)

ClassDa.sh does not collect personal information from anyone, including children under 13. There are no sign-ups, no chat and no uploads to us, so there is no way for a child's information to reach us through the app. Student information a teacher enters stays on the school's or teacher's own device, under the school's control; we never receive, store or have access to education records. We describe ClassDa.sh as built so no student data ever reaches us rather than “FERPA or COPPA certified”, because no such certification exists.

Districts: we are happy to sign the Student Data Privacy Consortium's National Data Privacy Agreement, or your own agreement. Email david@classda.sh. The tech team notes list every address the board uses.

If you believe a child has sent us personal information (for example by email), contact us and we will delete it.

If you email us

If you contact us, we receive your email address and whatever you write. Mail to david@classda.sh is forwarded by our domain registrar to our regular inbox. We use it only to reply and to fix what you report, and delete it when it's no longer needed. Please don't include student names.

Your choices and rights

We do not sell or share personal information and do not use it for advertising. The only personal information we could ever hold is an email you send us. Wherever you live, you can ask what we have, or ask us to correct or delete it, and we'll answer within 30 days. Your class's information is on your own device, so you control it directly (see Erasing it above).

Where information is processed

ClassDa.sh is run from the United States. Vercel, the weather services and our email provider may process the technical information described above in the United States and other countries.

A laptop and a board

ClassDa.sh never links a laptop and a board through our servers, because we don't run any. A laptop plugged into the board uses Present, which stays on that one computer. A board with its own computer gets the class from a classroom file you carry over yourself (a USB stick or your school drive). There's no link or online way to move a class, so it never passes through anyone's servers.

Changes to this policy

If we change how ClassDa.sh handles information, we'll update this page and the date at the top before the change takes effect. We will never start collecting student information.

Contact

Email david@classda.sh.