Privacy policy
Who is responsible
This website is operated by Pepe Hernandez (Spain). Contact: pewdiepier50@gmail.com.
The short version
- There are no accounts, sign-ups or forms.
- Your drawings are checked entirely in your browser and are not sent to us.
- On the free-drawing page, a code for each structure you draw that is not among this site's exercises is sent to PubChem, a public database in the United States, to look up its name. You can turn this off on that page (see "PubChem name lookups" below).
- Your practice progress is saved only in your own browser.
- The site currently shows no advertising and uses no analytics.
Practice progress stored in your browser
To remember which exercises you have solved, the site saves a small record in your browser's local storage under the keyochem-practice.progress.v1. It contains exercise identifiers, attempt counts, whether you used hints or revealed the answer, and dates. It never leaves your device and we cannot see it. You can delete it at any time with the Reset button on the Progress page or by clearing this site's data in your browser. If your browser blocks storage, the site still works but does not remember progress.
The site also remembers three settings in local storage, again only on your device: which drawing editor you chose (ochem-practice.editor.v1), the language you chose (ochem-practice.lang.v1) and whether PubChem name lookups are turned on (ochem-practice.pubchem.v1).
PubChem name lookups (free drawing)
The free-drawing page looks up the names of the structures you draw in PubChem, a database run by the National Center for Biotechnology Information of the US National Library of Medicine (NLM). This is on by default and applies only to structures that are not among this site's exercises; you can turn it off, and on again, on the same page. For each such structure your browser sends PubChem its InChIKey: a 27-character code calculated from the structure, which contains nothing about you. As with any web request, PubChem's servers in the United States also receive your IP address and technical information such as your browser type. We do not receive or store these lookups. How NLM handles this information is described in its privacy and security policy.
Hosting and server logs
The site is hosted by Cloudflare. Like any web server, the host processes technical information needed to deliver pages and protect the service, such as your IP address, browser type, the pages requested and the time of the request. See the host's privacy policy.
All program code, including the chemistry engine and the drawing editor, is served from this site; no fonts or scripts are loaded from other services. Apart from the PubChem lookups described above, your browser contacts no other service while you use the site.
Advertising
The site does not currently show advertising. If that changes, this policy will be updated before any ads appear.
Children
The site is intended for university students and other adult learners, and is not directed at children under 13.
Your rights
Depending on where you live (for example under the EU or UK General Data Protection Regulation), you may have rights to access, correct or delete personal data and to object to its processing. Because the site keeps no accounts and stores progress only on your device, we normally hold no personal data about you. For any request or question, use the contact details above.
Changes
If this policy changes, the date at the top of this page will change too.