Privacy

Last updated September 30, 2026.

Your patterns stay on your device: Pattern Reader has no account and no server that receives them.

What stays on your device

Your patterns, your progress, the timer, and the pictures and charts you add are saved in your browser (IndexedDB). Your display preferences (text size, dark background, full-page mode), the online row counter and the last project you opened are saved in the browser’s local storage (localStorage). None of this is sent to a server.

Audience measurement

To learn which pages are useful, Pattern Reader uses Umami, a measurement tool installed on our own server (at OVH), with no cookie and no identifier: nothing can recognise a person from one visit to the next, and nothing is sold or handed to an ad network.

What is sent: the page viewed, the country, the type of device and browser, the language, and the actions listed below. Two calendar dates stored in your browser are only used to tell whether a visit is a return (a day, a week, a month later): they are never sent as they are.

What is never sent: the text of a pattern, a file name, anything you type in a search.

The actions measured

Each action below is counted, without the content of what you typed:

a pattern is pasted (its length rounded to the hundred, never its text)
a pattern is split into steps (the number of steps, not their content)
you move on to the next step
an abbreviation is hovered in the reader
a project is resumed on open
a PDF is imported (number of pages and pictures)
a PDF could not be read (the reason it failed)
the practice row on an abbreviation page is edited
a pattern is converted between US and UK conventions
a new project is opened
a project is resumed from the list
a project link is copied (former button, removed)
a pattern link is copied
a project is opened from a received link
a backup is downloaded (number of projects)
a backup is imported again (number of projects)
a return, one day after the first visit
a return, 2 to 7 days after the first visit
a return, 8 to 30 days after the first visit
a return, more than 30 days after the first visit
step 5 of a pattern is reached
step 20 of a pattern is reached
step 50 of a pattern is reached
the waiting-list line is shown
the waiting-list link is clicked
the text size or dark background is changed
full-page mode is entered or left
a button of the welcome banner is clicked (example or paste)
you jump straight to a step
printing is opened
the online row counter passes a multiple of ten
a picture from a PDF pattern is enlarged
a chart is added (image or PDF)
a chart is shown
a chart is transcribed to text (number of rounds, convention)
a gauge is compared with the pattern’s (unit, advice)
a glossary filter is changed (never the search text)
a first entry on the “read a pattern in the other language” page (length)
the browser’s install prompt is shown
the app is installed

Share links

When you copy a pattern or project link, the pattern is carried by the link itself, after the # sign. That part of an address is never sent to the server that hosts the site: the link goes through no Pattern Reader server.

The waiting list

If you follow the “Tell me more” link of the waiting list, you land on a form hosted by Tally. If you leave your email address there, it goes to Tally and is only used to tell you when a version that syncs between devices exists. Filling in nothing sends nothing.

Erasing your data

In “My projects”, delete a project to remove it from the device. To erase everything at once, clear the site’s data in your browser settings. Since nothing is kept anywhere else, there is nothing else to ask for. My projects

Contact

A question about your data? Write to us on the project’s Discord. Open Discord

What comes next

If a paid option to sync between devices ever exists, this page will be updated before it goes live.