Your data, and what this site does with it

The short version

This site sets no cookies, uses no advertising, and contains no third-party trackers or fingerprinting. Nothing follows you across the web. It does count requests at the server, in aggregate, and that counting is described in full below.

It does not sell, share, or build profiles of its visitors, and it asks you for nothing in order to read it.

The catalogue's interactive tools run entirely in your browser: what you paste or type into them stays on your device. The one exception is the red room (/dev/out), whose tools send a query, when you press Ask, straight from your browser to the official service they name; nothing goes to this site's servers.

Only four things involve data at all, and each is explained below: a handful of preferences and one short reading trail saved in your own browser, the standard connection logs that every website visit creates at the hosting layer, the aggregate request counts this site keeps at the server, and any message you choose to send by email.

Who is responsible

This is the personal website of Rodolfo Nützmann (ronutz.com). For any privacy question, or to exercise any of the rights described below, write to hello [at] ronutz.com. Enquiries are handled directly by Rodolfo Nützmann, as the data controller.

No cookies, no third-party analytics, and what is counted instead

This site sets no cookies of any kind. It uses no third-party analytics service (such as Google Analytics or Plausible), no advertising network, no social-media tracking pixels, and no device fingerprinting. No script on the page reports anything about you. What the site does keep is a count, made at its own server as it answers each request. Two separate records are written, and they are deliberately kept apart so that neither can be matched to the other. The first records the address asked for and whether a page was found there, the language, the visiting country as your network reports it, whether the request came from a person or from a known crawler, and, for a person, the coarse class of device (phone or tablet, desktop or laptop, or other). The second records only a referring address, when your browser sends one and a page was served, and carries nothing else at all - no page, no country, no time correlation with the first. Your IP address is never written. Your browser's user agent and the network your connection comes from are never written either; they are read only to decide whether the request came from a person or a crawler (a browser on a cloud or hosting provider's network counts as a machine) and, for a person, which class of device sent it, and what is kept is a label such as "search engine", "monitoring tool" or "phone or tablet". No identifier of any kind is used, so there is no visitor to profile, no session to reconstruct, and nothing to share.

What is stored in your browser

A few small things, all in your browser's local storage, none of them ever sent to this site or to anyone else, each clearable through your browser at any time: your visual theme (ronutz-theme); the language you last used, so the bare domain can send you back to it (ronutz-lang); whether glossary hints are shown (ronutz-glossary-hints); any keyboard shortcuts you rebound (ronutz-shortcuts); whether the search box starts empty each time you open it (ronutz-search-fresh); the cards-or-list density you chose on an index page (ronutz:view:*); the Guided or Directory reading you chose on the Learn and Tools pages (ronutz:hub:*); the last six pages you opened, so the home page can offer them again under "Continue where you left off", with a button that forgets them (ronutz:recent:v1); and, on two dev-room pages only, a motion switch and a practice score (ronutz-mb-motion, ronutz:subnet-drill:stats). One session-only flag (ronutz.privPreview) exists for the author's private preview of unpublished pages and is never set for a reader. Nothing else about you is stored on your device.

Theme, language, and what this site remembers

Your preferences, your reading trail and the two dev-room values are stored only in this browser's localStorage, on your device; the theme is applied before first paint on your next visit. There is no cookie, no account, and no server that ever sees any of it, which also means none of it can follow you: a private window, cleared site data, or a different browser or device starts you back at the defaults by design. Your language works in two layers: it lives in the address itself (/en/ and /pt-BR/ are different pages, so bookmarking or sharing a URL in your language keeps it), and the last language you used is also remembered in this browser, so that a visit to the bare domain lands on it rather than on the default. That is the whole trade: with no accounts and no tracking, preferences can only live where you can see and delete them.

Keyboard shortcuts

The site has a handful of single-key shortcuts for quick navigation, active on every page. Press b for the boss key, which hides whatever you are reading behind a convincing 1980s work application until you press any key or click; t jumps to the Tools index; l to the Learn index; m opens the Mega Brain console; and z opens Buzzword Bingo. These are deliberately inert whenever you are typing: if the focus is in a text field, a paste box, a search input, or any editable area, the keystroke belongs to that field and the shortcut does nothing, so nothing you type is ever swallowed. They are also ignored when a modifier key is held, so your browser's own combinations such as Ctrl+T for a new tab are never shadowed. The shortcuts run entirely in your browser, add no tracking, and are purely a convenience you can ignore.

Hosting and server logs

The site is delivered through Cloudflare, which provides its hosting and content delivery. As with any website, loading a page means your device connects to a server, and Cloudflare, acting as the hosting provider, processes basic connection data, including your IP address and standard request details, in order to deliver the pages to you and to protect the site against abuse and attack. This processing is necessary to operate and secure the site (a legitimate interest under GDPR Article 6(1)(f), and the corresponding bases under LGPD Articles 7 and 10). It is retained only briefly by the provider and is not used here to identify or track you.

The tools run in your browser

The decoders and calculators on this site, for JWTs, IP addresses, certificates and the rest, compute entirely within your browser. The values you enter are processed on your own device and are never sent to a server. The one exception is the red room (/dev/out), whose tools exist to ask a live service: when you press Ask, your query goes from your browser directly to the official service named on screen, a domain registry for example, and this site's servers never see it. The programmatic interface (an API) documented on this site follows the same rule, stateless and logging no query or request body; ronutz.com does not serve it.

If you contact me

The contact form does not submit to any server. Instead it opens a pre-filled message in your own email application, which you then send yourself from your own account, so nothing passes through a third party. If you do write, whether through the form or directly, I receive the information you include, such as your name, email address and message, and use it only to reply to you. I keep it only for as long as needed to deal with your enquiry, do not use it for marketing, and do not share it.

Processing outside your country

Because Cloudflare operates a global network, the connection-level processing described above may take place on servers located outside your own country, including outside Brazil and the European Economic Area. Where personal data is handled internationally in this way, it is processed under the safeguards offered by the provider concerned.

Children

This site is intended for a professional, general audience. It is not directed at children and does not knowingly collect personal data from them.

Your rights

Depending on where you live, you have rights over your personal data, including to access it, to have it corrected or deleted, to object to or restrict its processing, to request a copy in a portable form, and to be told how it is handled. To exercise any of these, simply write to hello [at] ronutz.com. Because so little personal data is ever processed here, in practice there is usually very little to act on, but the channel is always open.

If you are in the European Economic Area or the United Kingdom, you also have the right to lodge a complaint with your local data protection supervisory authority.

If you are in Brazil, you hold the rights set out in Article 18 of the LGPD, and may also contact the national data protection authority (the ANPD).

Changes to this notice

If this notice changes, the revised version will be published on this page and the date below will be updated. Material changes will not be applied retroactively.

Last updated: October 13, 2026

• October 13, 2026: The Portuguese notice re-read beside the English, and a lost qualifier restored.
• October 7, 2026: The visitor count records whether a page was found; the user agent and network reads are explained; the Guided or Directory choice joins the list of stored values; the local-first promise is scoped to the catalogue, with the red room named as the exception.
• October 6, 2026: The search box's reopen preference joins the list of stored values.
• October 5, 2026: Every key the site writes to the browser is listed, including the language last used, the keyboard shortcut bindings and the trail of recently opened pages.
• July 3, 2026: Why preferences live only on this device, and nowhere else.