O(note)

O(note) lets you take notes directly on LeetCode and Codeforces question pages - no more requirement of changing tabs to write notes or have a disconnected notes area from your questions Features: - Floating notes panel that appears automatically on question pages, with autosave - Markdown support with live preview (toggle with Alt+K) - Labels/tags for organizing notes and fully custom labels — create your own on the fly - A dedicated View page to search, filter, and sort all your saved notes — filter by site or label - Export notes as Markdown (readable) or JSON (for backup) - Import JSON backups to restore your notes - Fully customizable via a settings page — toggle individual features on or off - Works on LeetCode and Codeforces, with more site support planned All your notes are stored locally in your browser (IndexedDB) — nothing is sent to any server. Your data stays fully private. This means there's no automatic cross-device sync, but you can move your notes between devices anytime using the export/import feature. Toggle the panel with Alt+L, switch between edit and preview mode with Alt+K.