Last updated: 24 September 2026
Privacy policy
In short
- Without an account, your drawings never leave your browser. They are saved on your computer only.
- With an account, the server keeps your e-mail, your name, your password (scrambled so nobody can read it) and the projects you choose to put online.
- No ads, no analytics, no tracking cookies. Your data is never sold.
- You can delete your account yourself at any time (menu of your name → Delete my account), and see or download your data by writing to [email protected].
1. Who runs Circuit Notebook
Circuit Notebook is made and run by one person, Tom Rousseau, a student in electronics and embedded systems in France, as an individual (not a company). Under the European data protection law (GDPR) I am the data controller: the person responsible for your data.
Contact for anything in this page: [email protected], or the contact form.
2. Using the app without an account
You can use the whole editor without signing up. Your projects, your own symbols and templates, your settings and keyboard shortcuts are saved in your browser (its storage called IndexedDB and localStorage). They are not sent to my server.
The flip side: if you clear your browser data or change computer, they are gone. Keep a copy of important projects (Export → Download .olg file).
3. What the server keeps when you have an account
| What | Why |
|---|---|
| Your e-mail address, your name, your username (if you choose one), the colour of your cursor, the date you signed up. | To create your account, sign you in and show who is who in shared projects. |
| Your password, never in clear: only a scrambled version (a hash, made with scrypt) from which the password cannot be read back. | To check your password when you sign in. |
| A sign-in key, kept in your browser. The server keeps only a scrambled copy. It expires after 30 days or when you sign out. | So you stay signed in. |
| The projects you put on the server: drawings, names, thumbnails, comments, version history (with who saved each version), who may open them (members, teams, invite links, rights per sheet). | To keep them for you, sync them between devices and share them. |
| Your friends and teams, and your personal library of symbols if you sync it. | To share projects with them in one click. |
| If you sign in with GitHub (when this button is offered): your GitHub account number, your GitHub name and your verified e-mail address. Nothing else: no access to your code. | To sign you in without a password. |
Legal basis: providing the service you asked for (GDPR, article 6.1.b).
Who sees what. People you share a project with see your name, username, colour, e-mail address, your cursor and your comments in that project. Your friends and team mates see your name, username and colour. Someone can send you a friend request only if they already know your exact e-mail or username.
As the administrator I see the list of accounts (name, e-mail, date, number and size of projects), to run the beta and its limits. I do not look inside your projects, unless you ask me to help with one.
4. The contact form
When you write to me with the form of the homepage, I receive your name (optional), your e-mail address and your message. They are saved on the server and e-mailed to me, so I can answer you (legal basis: your request, and my legitimate interest in answering it, GDPR article 6.1.f). I delete these messages once the conversation is over, and the server deletes them by itself after one year at the latest.
To stop spam, the server remembers your IP address for one hour (in memory, not in its database) to count the messages sent from it.
5. What I do not do
- No advertising, no audience statistics, no tracking pixels, no social buttons.
- No selling or renting of your data, and no use of your projects for anything other than giving them back to you.
- The fonts and images come from my own server: opening the site does not tell Google, Facebook or anyone else that you came.
6. Cookies and browser storage
Circuit Notebook sets no cookie of its own. It uses your browser's storage only for what
the app needs to work: your sign-in key, the server address, your settings and
shortcuts, your local projects and a copy of the online projects you opened (so they
still work offline). Cloudflare, which protects the site (see below), may set a
technical cookie to tell people from robots (__cf_bm, 30 minutes).
All of these are strictly necessary for the site to work, which is why there is no cookie banner.
7. The services that help run the site
A few companies handle data for me, only for the task below, under contracts that follow the GDPR.
| Service | What for | Where |
|---|---|---|
| Hetzner Online GmbH | The server that runs the site, the database, and its backups. | European Union (Germany) |
| Cloudflare, Inc. | Stands in front of the server: secure connection (HTTPS), protection against attacks, domain name, forwarding of e-mails sent to contact@. It sees the technical data of each visit (IP address, browser, page asked). | Worldwide, incl. the United States* |
| Brevo (Sendinblue SAS) | Sends me the messages of the contact form by e-mail. | European Union (France) |
| Google LLC (Gmail) | The mailbox where I read and answer e-mails sent to contact@. | Worldwide, incl. the United States* |
| GitHub, Inc. | Only if you choose "Continue with GitHub". | United States* |
* Transfers outside the EU rely on the EU–US Data Privacy Framework and on the European Commission's standard contractual clauses.
Ko-fi. The "Support" button opens Ko-fi, a separate site with its own privacy policy. If you give, Ko-fi and its payment provider handle the payment; I only see the name and message you choose to leave there.
8. How long data is kept
- Account: as long as it exists. When you delete it, your account, the projects you own (also for the people you shared them with), your friends, teams and library are removed at once. Comments you wrote in other people's projects stay there, as part of their work: ask me if you want them removed.
- Sign-in keys: 30 days at most.
- Projects on the server: until their owner deletes them. The automatic versions of the history are thinned out as new ones come (20 at most); versions you named stay until the project is deleted.
- Contact messages: one year at most (deleted automatically).
- Backups: to protect your work against accidents, the database is copied every night (the last 7 days are kept on the server, and Hetzner keeps its own copies of the last 7 days on other machines), and before each update of the site (the 5 latest). Something you delete therefore disappears from the backups as these copies are replaced.
9. Your rights
You can at any time:
- see the data I have about you, and get a copy of it;
- correct it (your name, username and colour can be changed in the app);
- delete it: your projects and your whole account, from the app (menu of your name → Delete my account);
- take it with you: projects can be exported from the app as files; I send the rest on request;
- object to a use of your data, or ask me to pause it.
Write to [email protected] from the e-mail address of your account (so I know it is you). I answer within one month.
If you think I do not respect your data, you can complain to the French data protection authority, the CNIL (cnil.fr), or the authority of your country.
10. Security
Every connection is encrypted (HTTPS). Passwords and sign-in keys are stored only in scrambled form. The server is not directly reachable from the internet: it is only reached through Cloudflare. The database is backed up every night. No system is perfect: if a problem ever puts your data at risk, I will tell you and the CNIL, as the law asks.
11. Young users
Circuit Notebook is made for students and engineers. If you are under 15, ask a parent before creating an account.
12. Changes
If this policy changes, the date at the top changes too. Important changes will be announced on the homepage, or by e-mail to account holders.