Privacy

Without an account. Your searches are processed to show results; we don't link them to you. If you play as a guest, your browser holds a random guest ID for the session so you keep your place in a game.

With an account. We keep your email address and username (through our sign-in provider, Clerk), and what you do in the app: games played and won, scores, your Elo rating, prompts you answered or missed, words you used, favorite words, saved searches, friends, and people you block. We also keep when the account was created and last used, and whether you've seen the welcome tour.

Premium. Stripe handles payment. We keep your Stripe customer and subscription IDs and your subscription status and renewal date, so we know Premium is active. Card details go to Stripe directly.

Feedback. When you send feedback from the app, we keep your message, the page you sent it from and the app's version, with your account if you're signed in. As a guest you can add an email address so we can reply; it's optional and used only for that.

Technical data. Our servers see your IP address with each request. We use it to limit how often searches can be made and to protect the service, and we keep the last IP address used by an account to stop abuse, such as enforcing a ban.

Chat. Messages in a game room go to the players in that room. They're checked against a list of slurs and abusive terms; repeated violations can lead to a suspension. Messages live only in the room's temporary state, which expires about two hours after the room goes quiet. We don't keep a chat history.

Usage analytics. We use PostHog to understand how features are used so we can improve them: which pages are visited, page speed, errors, and actions like starting a search or a game. It's set up without cookies and stores its identifier in your browser's local storage. What you type (searches, words) and usernames are removed before anything is sent, and we don't record clicks or sessions. When you're signed in, events are linked to your account ID, not your name or email.

Before some actions, such as creating a game room, an invisible check confirms the request comes from a person's browser and not an automated script. Usually you won't see it; occasionally it may ask you to tick a box.

As a condition of enabling invisible mode, this site uses Cloudflare Turnstile. Please review Cloudflare's Turnstile Privacy Addendum for details on data collection and privacy practices.

Some things never leave your browser: your theme, whether game sounds are muted, your recent searches, and whether you've seen the welcome tour. Clearing your browser's site data removes them. Signing in uses cookies set by Clerk, which are needed to keep you signed in.

• To run search, games, leaderboards, friends and your profile.
• To provide Premium features and manage your subscription.
• To keep the service safe: rate limits, moderation, suspensions and bans.
• To fix problems and decide what to build next, using aggregate usage.
• To reply when you contact us.

We don't sell personal data, and we don't use it for advertising.

Your username, and your results in games you play, are visible to other players in those games. Your username and rankings appear on leaderboards. If your profile is public, other people can see your stats and recent games on it; you can make it private. Friends can see when you're online.

These providers process data for us, only to provide their part of the service:

• Clerk: sign-in and account management.
• Stripe: payments and subscriptions.
• PostHog: product analytics.
• Sentry: error reports from our servers, so we can find and fix bugs.
• Cloudflare: network security, including blocking abusive IP addresses, and Turnstile bot checks.
• Google Cloud: hosting for our servers.
• Vercel: hosting for the website.
• Our database and cache hosting providers, which store the data described above.

We may also share information if the law requires it, or to protect the rights and safety of our users or the service.

We keep account data for as long as your account exists. Game rooms, including their chat, expire about two hours after they go quiet. When an account is deleted, we delete its data, except where we must keep something to meet legal or payment obligations.

• Make your profile private from your profile settings.
• Remove favorites, saved searches and friends at any time.
• Ask us for a copy of your data, to correct it, or to delete your account.

Depending on where you live (for example in the EU, UK or California), you may have further rights, including to object to or restrict some processing. Email admin@substring.app and we'll respond within 30 days.

Accounts are for people 13 and older. We don't knowingly collect personal data from children under 13.

By creating an account you confirm you're 13 or older, as our Terms of Use require. If we learn an account belongs to someone under 13, we delete it and everything it holds.

Anyone can search, play the Daily and join games without an account. Playing as a guest uses a random ID kept in the browser and a display name the player chooses, and doesn't ask for personal information.

Parents and guardians. If you believe your child under 13 has an account or has given us personal information, email admin@substring.app with the username or email address involved. We'll confirm the request with you, then delete the account and everything linked to it, and tell you when it's done. You don't need an account to ask.

Connections to substring.app are encrypted, access to our systems is limited, and passwords are handled by our sign-in provider rather than by us. No service can promise perfect security, so please use a strong, unique password.

If we change this policy, we'll update the date at the top. For significant changes we'll let you know in the app.

Questions about privacy: admin@substring.app.