Privacy Policy
Chunk Trainer (끊어읽기 암기장, the “Service”) is a study tool for memorizing English passages by breaking them into sense groups. This policy explains what information the Service receives, where it is kept, and how it is deleted.
Last updated: September 7, 2026
1. Using the Service without an account
You can enter passages, chunk them, listen along, and drill flashcards without signing in. In that case your passages and settings are never sent to our server; they are stored only in your browser (localStorage). Clearing your browsing data deletes them, and the Service has no way to read them.
Two features do require an account because they use our server: automatic translation and the word list.
2. Information received when you sign in
Sign-in is handled by Google. We request the scope
openid email profile and receive only the following:
| Item | Why we use it |
|---|---|
| Email address | Identifying your account, preventing duplicates, checking administrator status |
| Name | Displayed in the interface |
| Profile picture URL | Displayed in the interface |
We never receive or store your password. Google performs the authentication and we only receive the result.
3. Information you create
- Passages — title, the text you paste, the chunks and their Korean meanings, your progress, any YouTube URL and time range you attach, and playback settings
- Word list — the English words you save, their meanings, which passage they came from, and your progress
- Interface settings — whether hints are shown, which voice reads to you, and so on
- Email preference — whether you agreed to receive feature announcements, and when
This content is tied to your account and is not visible to other users.
4. Email notifications
When you first sign in we ask once whether we may email you about new features. We record your answer and the time you gave it. If you say yes, we send only short notes about newly released features to the address on your Google account — never advertising, and never to anyone else. Saying no changes nothing else about the Service, and you can change your mind at any time through the contact link below.
5. Cookies
We use a single cookie named session to keep you signed in. It is set with
HttpOnly, Secure and SameSite=Lax, so it cannot be read by JavaScript, and it expires
after 30 days. We do not use cookies for advertising or behavioral tracking.
6. Where data is stored and for how long
All data is stored in Cloudflare D1. Account and study data are kept until you delete your account. Session records stop being valid after 30 days.
When you delete a passage, a word or your whole account, the record is marked as deleted and immediately stops being shown or served to anyone, including you. The underlying row is kept for a short period so that an accidental deletion can be recovered on request, and is then erased. If you want your data erased right away, write to us at the link below.
7. Data shared with third parties
We do not sell your information or share it for advertising. The following data leaves our systems because the features depend on it:
| Recipient | What is sent | When |
|---|---|---|
| Google (Sign-In) | Authentication request | When you sign in |
| Google Translate | The English text or word being translated | When you use “fill Korean meanings”, save a word, or otherwise trigger auto-translation |
| YouTube | Video playback requests (IFrame API) | When you load a video in step 3 |
| Google Fonts | Font requests, including your IP address | On every page load |
| Cloudflare | Hosting and database | Always |
Automatic translation works by having our server call Google Translate’s public endpoint. This means the text you translate is transmitted to Google, and its handling from that point is governed by Google’s policies. Please do not use automatic translation for sensitive content — type the meaning in yourself instead. Because this is not an official API, the feature may also stop working without notice.
8. Your choices
- View — everything stored is visible under “My passages” and “My word list”.
- Export — “Save passages” downloads all of your passages as a JSON file.
- Delete — passages and words can be deleted from their screens. Once deleted they are no longer shown to you and cannot be restored from within the Service.
- Delete your account — write to us at the link below. Your account is closed, you are signed out, and your passages and words stop being served.
9. Children
The Service is not directed at children under 14, and we do not knowingly collect personal information from them.
10. Administrator access
Designated administrator accounts can see the list of registered users and the titles and progress of the passages they created. This access is used only for operating the Service and investigating problems.
11. Contact
For privacy questions or requests to access or delete your data, please write in the sheet below.
Open the feedback sheet
12. Changes to this policy
If this policy changes we will update the date at the top of this page. Significant changes will also be announced inside the Service.