Privacy Policy
Established: July 24, 2026 / Last updated: August 7, 2026
⚖️ This English text is a translation provided for reference only. The original Japanese version is the official, legally binding text. In case of any discrepancy, the Japanese version prevails.
All conversion and diagnosis in EPUB FACTORY happens 100% inside your browser. The images, PDFs, text manuscripts and EPUB files you load, and the EPUB files generated, are never sent to or stored on the Operator's servers.
technocyan ("the Operator") establishes this Privacy Policy ("the Policy") regarding the handling of user information on the service "EPUB FACTORY" ("the Service").
1. Basic Policy
The Service converts images, PDFs and text manuscripts specified by the user into EPUBs inside the browser, and reads EPUB files specified by the user inside the browser to point out issues. Data used for this processing stays only on the user's device; the Operator does not collect, transmit or store it. The Operator handles only the minimum information genuinely necessary to provide the Service.
2. Information We Never Collect
The Operator never collects any of the following:
- Images, PDFs and text manuscripts (pasted text, .txt, .docx) to be converted, and their contents
- EPUB files loaded into the Diagnosis Feature and their contents (including title, author, body text and images)
- Generated EPUB files
- Folder names and file names
- Book metadata you enter, such as book title, publisher/circle names or author names
- Personally identifying information such as name, address, phone number or email address (except when you contact us)
All of the above are processed inside your browser, and after conversion are saved to your device only through your own action (downloading). An EPUB file loaded into the Diagnosis Feature is discarded from browser memory once the diagnosis finishes, and is stored nowhere.
3. Information We Collect
To improve the Service and understand demand, the Operator collects only the following anonymous usage statistics. No individual can be identified from this information.
| Item | Source | Details |
|---|---|---|
| Site usage | GA4 | Page views, visits, session duration, traffic sources |
| Device / browser type | GA4 | Rough type such as Chrome / Safari, screen size, etc. (standard GA4 metrics) |
| Page view records (the Operator's own analytics) | Supabase | The path of the page viewed (query strings excluded), the host name of the referring site when you arrive from outside, a two-letter country code, and browser type. No cookies or persistent identifiers are used, and IP addresses and detailed browser information are not stored. Individual users cannot be tracked |
| Conversion mode | Supabase | Book type used (page-layout manga / webtoon / art book / picture book / magazine / text book) |
| Episode & image counts | Supabase | Number of episodes (chapters) and images per conversion |
| Success / failure counts | Supabase | Number of files converted successfully or unsuccessfully |
| Diagnosis statistics | Supabase | The book type diagnosed (fixed-layout / text), writing direction (vertical / horizontal), the identifiers and counts of the issues reported, the number of checks run, and browser type. Title, author, file name and body text are not included |
These statistics never include the contents of images, manuscripts or EPUBs, nor file names or book metadata.
4. Technical Information Associated with Access
As a web service, delivering the pages and files needed for the Service to work involves hosting providers and content-delivery networks (CDNs) temporarily receiving the IP address and browser information of the connecting party. This is how the web ordinarily works; the Operator does not use this information to identify or track individuals. Google's servers likewise receive similar technical information through Google Analytics 4 measurement, and the Operator does not use it to identify or track individuals.
5. Cookies
The Operator uses Google Analytics 4 (GA4) to understand how the Service is used. GA4 uses cookies to measure anonymous usage (page views, pages visited, session duration, use of conversion features, etc.). This information contains no personally identifying data such as names or email addresses.
Information collected by GA4 is managed by Google in accordance with Google's Privacy Policy. If you prefer not to allow cookies, disable them in your browser settings or use the Google Analytics Opt-out Add-on.
Note that the "page view records (the Operator's own analytics)" in Section 3 use neither cookies nor any persistent identifier. Each time a page is displayed, only the path, referring host, country code and browser type at that moment are recorded; by design, multiple visits by the same person cannot be linked together.
5-2. Advertising (Google AdSense)
To cover the cost of operating the Service, the Operator uses Google AdSense, a third-party advertising service provided by Google. Google and other third-party vendors use cookies (advertising cookies) to serve ads based on your prior visits to the Service or other websites (personalized ads). This mechanism does not give the Operator access to any personally identifying information about you.
If you prefer not to receive personalized ads, you can opt out in Google's Ads Settings. You can also visit www.aboutads.info to opt out of other third-party vendors' cookies used for personalized advertising. For details on how Google uses data in advertising, see Google's Advertising — Policies & Terms.
6. Third-Party Services
The Service uses the following third-party services. Technical information may be sent to these providers as described in Section 4. Please refer to each provider's privacy policy for how they handle information.
| Service | Purpose |
|---|---|
| Hosting (Vercel) | Serving and hosting the Service |
| CDNs (jsDelivr, etc.) | Delivering the in-browser conversion engine |
| Google Analytics 4 | Measuring usage, traffic and conversion rates |
| Google AdSense | Serving ads (see Section 5-2) |
| Google reCAPTCHA v3 | Preventing spam and abusive automated submissions on the contact form |
| Database (Supabase) | Storing the anonymous statistics in Section 3 (including the Operator's own page-view analytics) and contact-form submissions |
6-2. Contact Form
Content submitted through the contact form (inquiry type, message, and — only if you wish to receive a reply — an optional email address) is used solely to respond to your inquiry and is stored in the database (Supabase) above. It is never used for any other purpose or disclosed to third parties except as required by law.
The contact form also uses Google reCAPTCHA v3 to prevent spam and automated abuse. reCAPTCHA collects certain device and interaction information and sends it to Google to determine whether a submission is human. Use of reCAPTCHA is subject to the Google Privacy Policy and Terms of Service.
7. Purposes of Use
The anonymous statistics collected are used only to:
- Understand usage and improve the Service
- Analyze demand
8. Disclosure to Third Parties
The Operator does not provide or disclose collected information to third parties except as required by law. As noted above, the Operator holds no personally identifiable information.
9. Changes to this Policy
The Operator may revise this Policy as necessary. The revised Policy takes effect when posted on the Service.
10. Contact
For inquiries about this Policy, please contact:
Operator: technocyan
Contact: Contact form
Email: kamura.indiedev@gmail.com (if the form is unavailable)
End of document