Privacy, terms & notices

Privacy

Comprehendo is produced by Total Reality Engineering (“we”, “us”) and provides reading-comprehension practice at comprehendo.net. This page explains what data we handle and why. We keep it minimal: no ads, we don’t sell your data, and we don’t use your data to train AI models.

What we collect

• If you sign in with Google: your name, email address, profile picture, and Google account identifier. We use these only to create your account and sync your progress across your devices. We never see or store your Google password.
• Your learning data: your level, streaks, and saved vocabulary. If you are signed out, your progress and saved vocabulary stay on your device (in your browser). Words you ask to translate are sent to our server and Google Translate, and may be stored in a shared translation cache so the same lookup does not need another paid translation request. If you are signed in, we also store your saved vocabulary in your account so it syncs across devices.
• Anonymous usage analytics: we record simple events (such as opening the app or answering a question) against a random, anonymous device identifier - never tied to your name or email - to understand how the app is used. This contains no personal information.
• Technical data: your IP address and basic request information, used briefly to prevent abuse and keep the service secure.
• Review reminders you enable: your browser’s push-notification address and encryption keys, interface and learning languages, and the next time any saved word is due. We do not send or store the words or translations with the reminder subscription. You can turn reminders off from your saved words at any time.
• Feedback you choose to send: free-form feedback messages you submit through the in-app feedback button, including the email address or other information you decide to include, and any screenshot you choose to attach.

Who we share it with

We use a small number of trusted providers to run Comprehendo:

• Google - sign-in, and the AI services that generate exercises and translations.
• Cloudflare - hosting, our database, delivery of push notifications, and privacy-friendly usage analytics.
• Sentry - error monitoring and optional in-app feedback, which may record technical details when something goes wrong, plus the feedback messages and screenshots you choose to send.
• Ko-fi - only if you choose to donate, through their own website; we do not receive or store payment details.

We do not sell or rent your personal data to anyone.

Cookies & local storage

We use an essential cookie to keep you signed in, and your browser’s local storage to remember your settings and (when signed out) your progress. We do not use advertising or cross-site tracking cookies.

How long we keep it

We keep your account data for as long as your account exists. On-device data stays in your browser until you clear it. A review-reminder subscription is removed when you turn reminders off, when its push service reports that it has expired, or after 180 days without an app sync. Technical logs are kept only briefly. You can delete your account and associated data at any time - just contact us.

Your rights

You can access, correct, export, or delete your data, and you can sign out at any time. If you are in the UK or EEA, you have rights under the UK GDPR / GDPR, including the right to lodge a complaint with your data-protection authority. To exercise any of these, contact us at the address below.

Children

Comprehendo is not directed at children under 13, and we do not knowingly collect their personal data. If you believe a child has given us personal data, contact us and we will remove it.

Terms of use

By using Comprehendo you agree to these terms.

• The service. Comprehendo is a free language-learning tool, provided “as is”. We may change, suspend, or discontinue it at any time.
• Intellectual property. Comprehendo, including the app, source code, design, branding, and site content, is owned by Total Reality Engineering or our licensors. We grant you a limited, personal, non-exclusive, and non-transferable right to use the service for your own language-learning practice. You may not copy, reproduce, redistribute, sell, sublicense, or create competing services from Comprehendo except where the law expressly allows it or we give written permission.
• Acceptable use. Please do not attack, overload, scrape, reverse-engineer, or otherwise misuse the service, and do not use it for anything unlawful.
• Exercise content. Exercises are generated automatically for language practice. They may occasionally contain mistakes and are not a substitute for authoritative reference material. You may use generated exercises for personal practice, and we may store, cache, edit, reuse, or remove generated exercises to operate and improve the service.
• Feedback. If you send us feedback, bug reports, or suggestions, you allow us to use them to operate, improve, and promote Comprehendo without owing you compensation.
• Donations. Any donations (via Ko-fi) are voluntary, non-refundable, and do not entitle you to additional features.
• No warranty. Comprehendo is provided without warranties of any kind. To the fullest extent permitted by law, we are not liable for any loss arising from your use of the service.
• Changes. We may update these terms; we will change the date above when we do. Continued use means you accept the changes.

Third-party notices

Comprehendo is closed source, but it uses third-party software and services that remain governed by their own licenses and terms. Important components include:

• Application libraries: Next.js, React, Serwist, Zustand, Immer, i18next, Drizzle, Zod, Heroicons, Motion, NextAuth, DOMPurify, and related packages, primarily under permissive licenses such as MIT, Apache-2.0, BSD, and ISC. DOMPurify is available under MPL-2.0 or Apache-2.0.
• Build and infrastructure tooling: OpenNext for Cloudflare, Cloudflare Workers tooling, Sentry packages, Sharp and libvips image tooling, Tailwind CSS, TypeScript, ESLint, Prettier, Vitest, and Playwright. Some optional or development packages use additional licenses, including LGPL-3.0-or-later for libvips, MPL-2.0 for some tooling, FSL-1.1-MIT for Sentry CLI, and CC-BY-4.0 for browser-support data.
• External services: Google, Cloudflare, Sentry, and Ko-fi provide sign-in, AI, translation, hosting, monitoring, feedback, or donation services under their own terms.

Third-party notices are informational and do not change Comprehendo’s own proprietary license.