The cookie question, asked properly
A banner on a first visit, with three answers of one click each: accept, only necessary, or open the switches. Analytics is the single optional thing on this site and it stays off until it is allowed — before an answer, Google’s tags write nothing to your browser. The answer is kept in this browser, so the banner is asked once; the button at the foot of the cookies page reopens it, and the privacy and cookies pages now say all of this.
There are two categories of storage on this site, and only one of them is a question. Necessary is the sign-in session and the look you picked; analytics is Google Analytics, through Google Tag Manager, counting how many people arrive and which pages they read. There is no third category, because there is no advertising here.
What is stored, and when
Before you answer, nothing of ours. The page denies every storage category — analytics, and all three advertising ones — in the markup, before the tag manager loads, so Google's tags start in a state where they write no cookie and send cookieless pings at most. The switch for analytics turns that denial into permission, and nothing else does.
Your answer itself is kept in this browser's local storage, under m2h.consent, with the version of the question and the moment you answered it. That is why the banner appears once rather than on every visit, and it is read back on the next one so a granted category is granted again.
Three other things live in local storage and are not cookies and not optional: the theme, the language, and the conversions you have made in this browser and not saved. They never leave the machine.
The three answers, one click each
Accept all, Only necessary, or Customise to see the switches. Refusing is a button of its own and the close cross in the corner as well — a banner where "no" costs more clicks than "yes" is not a question, and the regulators who write about this say so in as many words.
Inside the switches, Necessary is on and cannot be turned off: refusing the session cookie means refusing to sign in. Analytics is the one switch that moves.
Changing your mind
The cookies page has a button that reopens the same switches, and it shows what you chose and when. Choosing again replaces the answer; clearing the site's data in your browser removes it, and the question comes back on the next visit.
Nothing here has anything to do with converting a file. That runs in your browser either way, with or without analytics, signed in or not.
Related: whether an online converter is safe, and sanitising Markdown safely.