Delivery, hosting and server logs
When you access the website, the server infrastructure processes technically necessary connection data, in particular your IP address, the time, the requested address (URL) and HTTP status code, and the headers sent by your browser (referrer, browser type and operating system). This serves to deliver the website and to keep it secure. The legal basis is Art. 6(1)(f) GDPR; our legitimate interest is a working and secure operation. Without this connection data the website cannot be accessed at all.
Hosting: The website and its database are not run by an external hosting provider but on the operator's own server in Germany (processing location: Germany; administered by the operator). No processor is therefore involved in the hosting. The server is not directly reachable from the internet; the connection is routed through a Cloudflare tunnel (see below).
Server logs: The web server (nginx) and the application containers log the connection data listed above. These access logs are subject to a regular limit of 14 days; this is an operational decision, not a statutory period. In case of a specific security incident, the necessary extracts may be kept separately until the investigation is complete. The logs are not combined with other data. Cloudflare's logs are not covered by this.
The connection is encrypted end to end with TLS (HTTPS).
Cloudflare as an upstream service
All traffic of this website passes through the network of Cloudflare, Inc., 101 Townsend St, San Francisco, CA 94107, USA (CDN, DNS and tunnel to the server). Cloudflare processes, among other things, your IP address, the requested URLs, timestamps, browser data and technical security information in order to deliver the website and to protect it from attacks. The legal basis is Art. 6(1)(f) GDPR; our legitimate interest is the secure and reliable delivery of the website without exposing our own server directly to the internet.
Processing outside the EU, in particular in the USA, is possible. Cloudflare is certified under the EU-US Data Privacy Framework; in addition, the Cloudflare Data Processing Addendum provides standard contractual clauses for such transfers (Art. 45, 46 GDPR). Depending on the protection features enabled, Cloudflare may set its own security cookies such as __cf_bm or cf_clearance; these are distinct from our sign-in cookies (section 4). Further information: Cloudflare privacy policy · Cloudflare cookies.
Advertising via Google AdSense (only if enabled)
To cover server and operating costs, advertisements via Google AdSense may be shown on individual content pages of this website (e.g. guides, rankings, calculators and database). The provider is Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland ("Google"), for users in the European Economic Area, Switzerland and the United Kingdom. You can tell whether advertising is currently active by the "Privacy settings" link in the footer: it only appears when advertising is switched on. If it is missing, no Google code is loaded and none of the processing described in this section takes place.
What happens when advertising is active: When you open a page with an ad placement, your browser loads Google's advertising script (pagead2.googlesyndication.com) and connects directly to Google servers (including googlesyndication.com, doubleclick.net, adtrafficquality.google, google.com). This processes your IP address, the page requested, browser and device information and – depending on your consent – cookies and similar identifiers. Google uses this data to select and deliver ads, measure impressions and clicks, detect invalid clicks and fraud, and for billing. Pages where you sign in or enter data (sign-in, my account, creating and editing events) as well as the legal notice and the privacy policy contain no ad placements.
Consent: Before advertising cookies are set or similar identifiers are read, a Google consent dialog ("Privacy & messaging", based on the IAB Europe Transparency & Consent Framework, TCF 2.2) asks for your permission. There you can accept, decline or select individual purposes and vendors. The legal basis for storing information on your device and accessing it is your consent under § 25(1) TDDDG; for the subsequent processing of personal data it is Art. 6(1)(a) GDPR. Google stores your decision in a cookie or in your browser's local storage (including FCCDCF, FCNEC) so the dialog does not appear on every visit; Google's advertising cookies are named e.g. __gads, __gpi, __eoi and IDE.
Personalised and non-personalised ads: If you consent, Google may personalise ads based on your interests and previous activity and use cookies and advertising IDs for this, also across devices. If you decline, Google only shows non-personalised ads; they are based on the content of the page and your approximate location (from the IP address) and may use cookies only for fraud prevention, frequency capping and measurement. Google is an independent controller for ad delivery; the advertising partners listed in the dialog only receive data to the extent of your consent.
Withdrawal: You can withdraw or change your consent at any time with effect for the future – via the "Privacy settings" link in the footer, which reopens the dialog. You can also turn off personalised advertising in your Google ad settings and delete or block cookies in your browser.
Transfers to third countries: Google may also process data on servers in the USA. Google LLC is certified under the EU-US Data Privacy Framework; in addition, Google uses standard contractual clauses (Art. 45, 46 GDPR). Further information: Google privacy policy · How Google uses information from sites that use its services · Advertising at Google · Types of cookies used by Google.