Freedive Breathing Trainer

Train your breath-hold for freediving — right from Chrome's side panel. Freedive Breathing Trainer is a free, privacy-first Chrome extension designed for freedivers and breath-hold enthusiasts. Run structured training sessions without leaving your browser. 🏊 Apnea Training: • CO₂ Table — Build CO₂ tolerance with PB-based hold, decreasing rest • O₂ Table — Deplete O₂ with PB-based increasing hold, constant rest • Hold Test — Test your static breath-hold with optional goal and relaxation breathing 🌱 Beginner: • Beginner CO₂ — Fixed safe table, no PB needed • Beginner O₂ — Fixed safe table, no PB needed 🧘 Breathing Patterns: • Relax — Gentle 4-2-8-4 pranayama breathing • Box Breathing — 4-4-4-4 equal-ratio calming breath • 4-7-8 Breathing — Deep relaxation and sleep aid • Breathe-Up — 2-0-8-2 pre-dive preparation 🔧 Advanced: • Custom Table — Build your own apnea or pranayama table, save, share & import ⚙️ Features: • PB-based training — tables adapt to your Personal Best automatically • Onboarding — set your PB on first launch for personalized tables • Clean side panel UI — train while browsing • Configurable rounds for all modes • Optional Breathe-Up warmup before apnea sessions • Table preview before starting CO₂/O₂ sessions • Contraction marking during hold phases • New PB detection — auto-prompts to update after Hold Test • Session history with stats (time, rounds, avg/max hold, contractions) • Voice coaching with independent voice language setting • Sound effects, vibration, and optional relaxation reminders during holds • Data export/import for backup and transfer • Auto-pause when you switch tabs • Keyboard shortcuts: Space (pause/resume), Esc/Q (stop) • Safety disclaimer and anti-hyperventilation reminders 🌍 6 Languages: English, Tiếng Việt, Español, Português, 日本語, 한국어 🔒 Privacy: All data stored locally on your device. No accounts, no tracking, no server calls. ⚠️ Safety: This app is for DRY (land-based) breath-hold training only. Never practice near water without a trained safety buddy.