Yomikata does not collect, transmit, or sell any user data. All processing (Japanese text tokenization, furigana generation) happens entirely within your browser using a bundled dictionary — no network requests are made with your browsing content. Settings, known-word lists, and saved words are stored locally in your browser's extension storage (and synced via Firefox Sync only if you have that enabled, subject to Mozilla's own sync terms) and are never sent to any server operated by Kazu Labs or any third party.