Freedive Breathing Trainer

About

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.