Privacy

The short version: there are no accounts, no cookies, no ads, and nothing is sold. We count page views and page speed with Cloudflare Web Analytics, which sets no cookies and does not identify you. What the site remembers stays on your device, and you can delete it whenever you like.

What stays on your device

These are kept in your browser's storage (local storage, one session-storage item that lasts only while the tab is open, and one browser database) on this device only. We never receive them.

• sw.questions.v1 — Questions I’m keeping: the questions you wrote on Your learning, each with your guess and, later, how you found out. To remove: Use "Forget my questions" on Your learning, or clear this site's data in your browser.
• sw.handicap.v1 — The Handicap Ledger, only if you turn it on: the date, the game and the head start you gave each time. To remove: Use "Delete the whole note" or untick "Keep a note" on the Handicap Ledger page, or clear this site's data in your browser.
• sw:theme — Your page-colour choice (Reading room or Study), if you picked one. To remove: Choose "Follow my device" in the footer, or clear this site's data in your browser.
• sw.chess.games.v1 — The chess games you finished here, so you can replay and review them. To remove: Use "Delete all my games" on My games, or clear this site's data in your browser.
• sw.chess.rating.v1 — Your chess rating against the bot, so it can pick opponents near your level. To remove: Clear this site's data in your browser.
• sw.told.v1 — The Told Book: the answers you typed for the book and its title, so you can print it later. Recordings and paper answers are never here. To remove: Use "Remove all answers from this device" on the Told Book page, or clear this site's data in your browser.
• sw.guess.v1 — Today's Guess: the low and high you gave for each question and whether the range held, so the page can show how your ranges are doing. To remove: Use "Remove my guesses from this device" on Today's Guess, or clear this site's data in your browser.
• sw.songbook.v1 — The Family Songbook: the titles and words of the songs you added. Recordings you attach are kept separately, in this browser's own database (sw-songbook), never uploaded. To remove: Use "Remove the songbook and recordings from this device" on the Family Songbook page, or clear this site's data in your browser.
• sw:board — Your board view on chess and Go boards (large board and pieces, high contrast), if you turned either on. To remove: Turn both switches off above any board, or clear this site's data in your browser.
• sw:aloud — Whether moves are read aloud by your browser's own voice (the Slow Table switch). Only the on/off setting is kept; nothing is recorded. To remove: Turn the Slow Table off, or clear this site's data in your browser.
• sw:door — Which door you asked the home page to put first, if you chose one. It only changes the order. To remove: Choose "No preference" on the home page, or clear this site's data in your browser.
• sw:table:v1 — Your answers to "who is at the table" and "how long have you got" on the home page, if you chose any. It only changes the order. To remove: Set both back to "Any" on the home page, or clear this site's data in your browser.
• sw.hiddenranks.setups.v1 — Hidden Ranks setups you chose to save (as short codes), so the setup clinic can tell you whether you have a habit. Only if you pressed "Save this setup". To remove: Clear this site's data in your browser.
• sw.hiddenranks.childroom.v1 — While you play Hidden Ranks with your child, the sealed code of your own setup, kept in this tab only so a reload can carry on the same game. It is never sent; your child's screen only ever gets the seal, and the setup itself at the end of the game. To remove: Close the tab: it is session storage and is gone when the tab closes.
• sw.gamenight.v1 — If you host a Hidden Ranks game night: the names you typed for the players, the pairings and the results, so the evening survives a reload. Only on this device; never sent. To remove: Press "Start a new night" on the Game Night page, or clear this site's data in your browser.
• sw.patience.v1 — Your game in progress on the Daily Table, the Patience Club or the Silver Deck — the moves you have made on the current deal, so you can come back to it. Replaced when the next deal arrives. To remove: Press "Start this deal again", or clear this site's data in your browser.
• sa.tableReceipts.v1 — The last few table receipts from deals you cleared here (the kind of each move, the move count and a check code; never the cards). They stay on this device, newest first, at most twelve. To remove: Clear this site's data in your browser.
• sw.room.v1 — While you play chess, Flags, Four in a row or Go online: the room code, so a reload can offer to rejoin the game. Kept only in this browser tab (session storage) and gone when you close it; never sent. To remove: Press "No thanks" on the rejoin offer, finish or leave the game, or close the tab.
• sw.learn.v1 — The lessons you have started or kept, whether each answer was solved or shown, and what you wrote in your own words. To remove: Use "Forget this lesson" on a lesson, or "Forget all my lessons" on Your learning.
• sw.lexicon.v1 — The words you named from their meaning in Wordplay and Word Tide, and the ones you asked to be shown. Not part of the monthly tally. To remove: Use "Forget my words" on Your learning, or clear this site's data in your browser.
• sw.tally.v1 — Whether you turned on the anonymous monthly tally, and the last month this device sent its three counts. To remove: Turn the tally off on Your learning, or clear this site's data in your browser.
• maia-models — A browser database (IndexedDB) caching the human-like chess model (about 55 MB), only if you turned that opponent on, so it isn't downloaded again. To remove: Clear this site's data in your browser.
• whetstone-go-models — A browser database (IndexedDB) caching the "plays like a person" Go model (about 28 MB), only if you chose that opponent, so it isn't downloaded again. To remove: Clear this site's data in your browser.

When the site talks to the internet

• Cloudflare (our host, sparkwhetstone.org). When: Every page you open. What: The ordinary request your browser makes for a web page. We set no cookies.
• Cloudflare Web Analytics (static.cloudflareinsights.com, cloudflareinsights.com). When: Every page you open, in every country. What: A short report that a page was viewed and how fast it loaded: the address of the page, the page it came from, and your browser type. It sets no cookies, stores nothing on your device, and does not identify you or follow you to other sites. We see only totals.
• Our chess and Go model files (cdn.spark-and-anvil.com). When: Only if you choose a human-like opponent (chess) or a "plays like a person" opponent (Go). What: A one-time download of the model, cached on your device. The model then runs on your device; your moves are never sent anywhere.
• The Spark & Anvil room service (sparkanvil.org). When: Only when you open or join a room on Play together or on The Caller's Table across distance. What: The room code, the nickname you type, your moves and the pre-set reactions (on The Caller's Table: the game, the table code, each call, and each "looked" or "line" — never a card). There is no chat. The room is deleted shortly after everyone leaves.
• Our anonymous tally (sparkwhetstone.org/api/tally). When: Only if you turn it on, on Your learning — at most once a month. What: Three counts (lessons kept, courses begun, games finished) and the month. No identifier. We keep only the monthly totals and do not store your IP address.
• Your browser's built-in AI model (only in browsers that have one ready). When: Only when you ask a question on a lesson. What: Nothing leaves your device: the model runs inside your browser, and we do not receive or keep your question.

Links to other sites

Some pages link to Project Gutenberg (www.gutenberg.org), Etymonline (www.etymonline.com), Spark & Anvil (sparkanvil.org), Fold Commons (foldcommons.org). Following a link takes you to their site, where their own privacy policies apply.

Children

This site is for grown-ups. If you play in a room with a child, the room follows Spark & Anvil's children's rules: nickname only, pre-set reactions only, no chat.

Changes

If what we keep ever changes, this page changes first. The list above is generated from the same code that does the storing, so it can't quietly fall out of date.