Last updated: July 2026
This notice describes how Rokusho (“we”, “us”, “our”) processes information when you use kotobay.com (the “Service”).
Information you provide. When you paste a YouTube URL, our servers receive that URL (including the video ID) so we can fetch captions on your behalf.
Information from YouTube. We receive whatever public caption metadata and text YouTube returns for that video — typically title, author/channel name, language, and transcript segments.
Information collected automatically. Like most websites, our hosting provider processes technical data needed to deliver the Service, such as IP address, request time, browser type, and referring URL. We use IP addresses for abuse prevention (rate limiting). We do not use this data to build advertising profiles.
What we do not collect on the web Service. We do not require sign-in, do not process payment card data, and do not intentionally collect sensitive personal information.
We process information to:
We do not sell your personal information.
If you are in the European Economic Area, the United Kingdom, or Switzerland, we rely on:
Cached transcripts (video ID, title, author, language, and caption text) are stored in Upstash Redis for up to 90 days, after which they expire automatically.
Rate-limit counters keyed by IP address are kept for up to one hour.
Hosting logs retained by Vercel follow Vercel’s own retention practices. We do not maintain a history of videos you transcribe beyond the cache described above.
We share information only as needed to run the Service:
We may also disclose information if required by law or to protect rights, safety, and security.
Kotobay is not affiliated with YouTube or Google. See our Terms of Use.
Our infrastructure providers may process data in the United States and other countries. Where required, we rely on appropriate safeguards (such as standard contractual clauses offered by our vendors) for cross-border transfers.
We use reasonable technical and organizational measures to protect information we process. No method of transmission or storage is completely secure; use the Service at your own risk.
Depending on where you live, you may have rights to access, correct, delete, or restrict processing of personal information we hold about you, or to object to certain processing.
Because we do not operate user accounts on the web Service, we may need additional details (such as the video URLs you submitted and an approximate time) to locate related cache entries. To exercise your rights or ask questions, open an issue on our GitHub repository.
If you are in the EEA or UK and believe we are processing your information unlawfully, you may lodge a complaint with your local data protection authority.
Residents of California and certain other U.S. states may have additional rights (access, deletion, opt-out of “sale” or “sharing”). We do not sell personal information or use it for cross-context behavioral advertising.
The Service is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe we have, please contact us and we will take steps to delete it.
We may update this notice from time to time. The “Last updated” date above will change when we do. Continued use of the Service after changes are posted means you accept the revised notice.
The Kotobay Chrome extension (available separately in the Chrome Web Store) adds a transcript panel to YouTube watch pages. It is designed to be local and private:
localhost:8787) on your computer, you may choose to use the Save feature to file transcripts into local Projects. This communicates only with software on your machine; it is not required for the extension to work. The extension requests localhost access only when you click Save.The extension is not affiliated with YouTube or Google. See our Terms of Use.
Questions about privacy: open an issue on our GitHub repository or visit rokusho.com.