Privacy Policy

Deduce is built to be played with as little personal data as possible. You can play fully anonymously; signing in is optional and only exists to save your streak across devices.

Last updated: 31 August 2026.

What we collect

• Anonymous play. When you first open Deduce we set an anonymous session cookie so we can track your streak and which puzzles you've solved. This is not tied to your name or email.
• Gameplay data. Your attempts, solve times, scores and streaks — needed to run the game, the leaderboard and your streak.
• Optional sign-in (Google or email). If you choose "Save your streak", we store a stable account identifier and your display name and email — only to link your progress to a durable account (and, for the eBook, to deliver your PDF). With Google sign-in we receive a verified token, never your Google password; with email sign-in we use one-time codes, no password at all.
• Android app only — advertising ID. If you use the Deduce app from the Google Play Store, Google's Firebase Analytics collects your device's advertising ID and records when you open the app and when you start or finish a puzzle. We use this for one purpose: to find out which of our app adverts brought people who actually play, so we stop paying for installs that never open the app. It is shared with Google Ads for that measurement. You can reset or delete this identifier at any time in Android Settings → Privacy → Ads. This does not apply to the website or to an app installed from your browser.
• Payments (if you buy). Pro and eBook payments are processed by Razorpay under its own privacy policy — we never see or store your card or UPI credentials. We keep your subscription status and transaction identifiers so we can grant what you paid for, handle refunds, and meet tax rules.

How we use it

• To generate and validate the daily puzzle, score it fairly, and rank the leaderboard.
• To keep your streak and history, and to merge your anonymous progress into your account if you sign in.
• To understand—in aggregate—how the game is used so we can improve it.

What we don't do

• We don't sell your personal data.
• We don't show you any advertising, and we don't let anyone advertise to you inside Deduce. We do advertise Deduce itself elsewhere — and in the Play Store app we measure whether those adverts worked, as described under "What we collect".
• We use product analytics (PostHog) to understand how the game is used — events like "puzzle started" tied to a random visitor identifier stored in your browser, and session replays of in-app interactions to find usability problems. Analytics data contains no puzzle solutions and is never sold.

The in-app assistant (Asha and Saarathi)

Deduce has a chat assistant: Asha answers questions about the app and the plans, and Saarathi (part of Pro) coaches you on the puzzle you are playing. Using it is entirely optional — nothing in the game requires it.

• What is stored. Your message, the assistant's reply, the puzzle in context (its type, its difficulty, and whether the round had finished), your account or anonymous session identifier, and the time.
• Where it is processed. Your message is sent to Cloudflare Workers AI, which runs an open Llama 3.2 model on Cloudflare's own network. It is not sent to any other AI provider, and under Cloudflare's terms these inputs are not used to train the model.
• Why we keep it. The assistant is an AI and it can be wrong. We read these conversations for one purpose: to find wrong or unhelpful answers and fix them. They are never sold and never used for advertising.
• What not to type. Please don't put personal details — phone number, address, exam roll number, payment information — into the chat. The assistant never needs them, and a chat you send is stored.

Google & YouTube API Services

Deduce uses Google API services in two limited ways:

• Google sign-in (optional, described above) — used only to save your streak to a durable account.
• YouTube uploads (our own channel). Deduce's internal publishing tool uses YouTube API Services to upload our videos to our own YouTube channel (@deducepuzzles). It acts only for the account that explicitly authorizes it (scope: manage your YouTube videos) and touches no other user's YouTube or Google data.

Deduce's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Use of YouTube API Services is also governed by the YouTube Terms of Service and the Google Privacy Policy. You can revoke Deduce's access to your Google account at any time via your Google security settings.

Data retention & your choices

You can play without an account and clear the cookie any time via your browser. To request deletion of an account (Google or email sign-in), contact us (see below) and we'll remove the associated account and gameplay records; transaction records we're legally required to keep (tax/accounting) are retained for the statutory period only. Chat conversations with the assistant are stored against your account or session and are deleted along with it.

Contact

Questions or data requests: get in touch.