Privacy Policy — Hannari

Effective date: 2026-07-06

Last updated: 2026-07-06

Summary

Hannari is a browser extension that adds furigana (hiragana readings) above kanji on Japanese web pages. We designed Hannari with privacy as a core principle. This policy explains what data we handle and how.

Short version

• Hannari processes web pages entirely in your browser. No page content ever leaves your device.
• We do not track your browsing activity.
• We do not use analytics inside the extension.
• We do not sell, share, or rent any user data.
• Free users without an account: all data stays on your device.
• Accounts and cross-device sync are optional, and used only for Pro features.

What the extension does on your device

When Hannari is active on a page, it:

1. Reads the visible text content of the page to detect Japanese characters.
2. Tokenizes the Japanese text using a dictionary bundled inside the extension.
3. Inserts furigana annotations into the page’s DOM in your browser.

All of this happens locally on your device. No text, no URLs, no page content is transmitted to any server.

Data stored locally

The extension uses chrome.storage.local to remember:

• Your settings (appearance, JLPT level, layout, reading system, etc.)
• Which sites you’ve enabled or disabled
• Your learned kanji and study progress
• Your account session, if you are signed in

For free users without an account, all of this stays on your device and is never transmitted.

Accounts

Hannari offers optional accounts. When you create one, we collect:

• Your email address and name
• A securely hashed password

If you sign in with Google instead, we receive your Google account’s email and name. We never receive your Google password.

You can use Hannari’s free features without an account. An account is required only for Pro features and cross-device sync.

Hannari Pro & trial: data we sync

When you have Hannari Pro (or an active trial) and are signed in, the extension syncs the following to our servers so it follows you across your devices:

• Your extension settings (appearance, JLPT level, layout preferences)
• Your learned kanji and study progress (which kanji, their readings, and your review schedule)

This sync is tied to your account. Free users, without Pro or an active trial, do not sync — their settings and progress stay entirely on-device.

Device management (Pro)

So you can see and control where your Pro account is active, we store for each signed-in device:

• A randomly generated device identifier (this is not derived from your hardware)
• Your browser name and operating system (for example, “Chrome on Windows”)

You can view and remove your devices at any time from your dashboard.

Session validation

While you are signed in, the extension periodically contacts our server (about every six hours) to confirm your account and subscription status are current — for example, so a Pro upgrade or trial expiry is reflected without signing in again. This transmits only your session token. It does not send any browsing data or page content.

Payments

Payments are processed by Paddle, our merchant of record. Paddle collects:

• Your email address
• Billing details necessary for payment processing
• Country of residence (for tax compliance)

We receive from Paddle:

• Your email address
• Your purchase confirmation
• Your country (for tax records only)

We use this information only to:

1. Activate Pro on your account
2. Provide customer support if you contact us
3. Comply with legal and tax obligations

We retain purchase records as required by applicable tax laws. We do not use your email for marketing without explicit opt-in. We never see or store your card details.

Optional integrations

If you use the WaniKani import feature, the extension contacts WaniKani’s API using an access token you provide, to import your kanji. This happens only when you initiate an import. Your token is used for that request and is not stored beyond the kanji it imports.

Third parties

• Paddle processes payments. See their privacy policy at https://www.paddle.com/legal/privacy and their buyer terms at https://www.paddle.com/legal/checkout-buyer-terms
• Google — if you choose to sign in with Google, Google’s sign-in service authenticates you. See Google’s privacy policy at https://policies.google.com/privacy
• WaniKani — only if you use the optional WaniKani import (see above).
• We do not use any other third-party services that receive user data.

Your rights

You have the right to:

• Request a copy of the data we hold about you
• Delete your account and associated data at any time from your dashboard (subject to legal retention requirements for purchase records)
• Request deletion by contacting us, if you prefer
• Withdraw consent for processing at any time

Deleting your account permanently removes your account, settings, learned kanji, study progress, and device records from our servers.

To exercise these rights, email us at [email protected].

Changes to this policy

If we update this policy, we will change the “Last updated” date above. Material changes affecting how we handle data will be announced through the extension or via email to Pro users.

Contact

Questions about this policy? Email [email protected].

Hannari is operated by Hannari Studios.