privacy

Privacy and cookies

Eigendrum has no accounts, no sign-up and no login. It does use analytics and advertising, and this page says exactly what that means, who receives what, and how to switch it off.

Last updated: 14 August 2026.

The short version

• The drum is solved on your device. Meshing, the finite element solve and the audio all run in your browser. The shape you draw is not uploaded to a server for processing, because there is no application backend to upload it to.
• No account, ever. Nothing asks for your name, email or any other identifying detail in order to use the instrument.
• There is advertising and there are analytics. Both involve third parties who set cookies and receive your IP address. Details below.
• Nothing is sold. I do not sell or share personal information for money.

Who I am

Eigendrum is built and run by Basel Ashraf, an individual, not a company. For any privacy question or request, email u2679054@uel.ac.uk. I am the data controller for this site.

What is collected, and by whom

1. Hosting (Vercel)

The site is hosted by Vercel, which processes standard server request data in order to serve pages at all: IP address, the URL requested, user agent, referrer and timestamp. This is ordinary web-server logging and is necessary for the site to function and to stay available.

The deployed site also uses Vercel Web Analytics and Vercel Speed Insights, which produce aggregate page-view and performance measurements. These are designed to work without cookies and without building a profile of you.

2. Analytics (Google Analytics 4)

Google Analytics 4 is used to understand how many people visit, which pages they read and roughly where in the world they are - country level. It sets cookies and Google receives your IP address as part of the request.

I have configured it not to record the URL fragment. That matters here specifically: the shape you draw or the formula you type is stored in the part of the address after the # - for example #f=p:1 + 0.3cos(5t). Browsers never send that fragment to the web server, and Analytics is set to report only the origin and path, so the shapes you make are not recorded in analytics.

Google signals, User-ID collection, user-provided data collection and ads personalisation are all switched off on this property.

3. Advertising

Current status: advertising is running, served by Monetag. On this site their script is the only advertising script, and there is no other third-party ad code of any kind. Anyone running the project from source gets no ad network at all through the development server, which removes the tag before serving a page.

Eigendrum is ad-supported, because that is what pays for the domain and keeps the tool free with no account and no paywall. Two formats are in use. One is an in-page banner that Monetag place and size themselves rather than filling a reserved slot, so its exact position is theirs to choose and not something this page can state precisely. The other is a labelled sponsored link in the footer and at the foot of the written pages; it is an ordinary link, loads no script and no iframe, and does nothing at all unless you choose to click it. Its destination is picked by the ad network per visitor, which is why the wording next to it does not promise what is on the other side.

What was ruled out deliberately is the more informative part: no pop-ups, no pop-unders, no full-screen or interstitial overlays, and no browser notification prompts. Formats that hijack a click were rejected outright because drawing here is clicking and dragging, and an advert that redirects you mid-stroke would break the only thing the site does.

Advertising works through third parties, and that has consequences worth stating plainly:

• Third-party vendors use cookies and similar technologies to select and measure ads, including on the basis of your prior visits to this and other websites.
• Those vendors receive your IP address and coarse location as an unavoidable part of serving a request, and use it for fraud prevention and frequency capping even where ads are not personalised.
• I do not receive, and never see, any individual-level data from them. What I get is an aggregate revenue report.

You can opt out of personalised advertising industry-wide at any time:

• aboutads.info/choices (Digital Advertising Alliance)
• NAI opt-out (Network Advertising Initiative)
• Your Online Choices (Europe)
• If the partner turns out to be Google, also Google Ads Settings.

If you are in the EEA, the UK or Switzerland, you are shown a consent choice before personalised advertising cookies are set, and you can change or withdraw that choice at any time. Where you decline, non-personalised ads may still be served; those still require limited data such as your IP address and coarse location in order to fight fraud and meet legal duties.

4. Fonts and assets

The typeface is embedded directly in the stylesheet as a data URI rather than fetched from a font CDN, so no third party is contacted to render text. Every other asset the instrument needs is served from this domain.

What is stored on your device

• Analytics cookies set by Google Analytics, to distinguish visitors and sessions.
• Advertising cookies, once advertising begins, set by the advertising partner and its vendors as described above, together with a record of your consent choice where one applies. None are set today.

You can clear or block cookies in your browser settings at any time. Blocking them does not stop the instrument working: the solver, the audio and the drawing are all local and do not depend on any cookie.

Legal bases (UK and EU GDPR)

• Serving the site and keeping it secure: legitimate interests.
• Analytics and advertising cookies: your consent, where consent is required in your region. You may withdraw it at any time.

Your rights

Depending on where you live, you may have the right to access the personal data held about you, to have it corrected or deleted, to object to or restrict its processing, to data portability, and to withdraw consent. If you are in California, you may have the right to know what is collected, to request deletion, and to opt out of "sharing" for cross-context behavioural advertising - I do not sell personal information.

To exercise any of these, email u2679054@uel.ac.uk. Be aware that I hold almost nothing directly: I see aggregate reports, not individual profiles. For data held by Google, their own tools are more effective than a request to me - My Activity and Ads Settings.

UK residents may complain to the Information Commissioner's Office; EEA residents to their national data protection authority.

Retention

Analytics data is retained according to the Google Analytics property setting, which is 14 months, after which it is deleted by Google. Server logs are retained by Vercel under their own schedule. I do not keep a separate copy of either.

Children

Eigendrum is a general-audience educational tool and is not directed at children under 13. I do not knowingly collect personal information from children. If you believe a child has provided personal information, email me and I will delete it.

International transfers

Google and Vercel are US-headquartered and may process data outside your country, including in the United States, under the transfer mechanisms set out in their own terms - typically Standard Contractual Clauses and the EU-US Data Privacy Framework.

Third-party privacy policies

• Google Privacy Policy (Analytics and AdSense)
• How Google uses information from sites that use its services
• Vercel Privacy Policy

Changes

If this policy changes materially, the date at the top of this page changes with it. The revision history is public, because the whole site is: github.com/BaselAshraf81/eigendrum.