# Brizzy

> Free, browser-based guided breathing app with visual pacers, soundscapes, and AI voice coaching. No install, no account required. Start a session in seconds.

Brizzy runs entirely in the browser — desktop and mobile. Core features are free forever, with no ads. The app supports 7 languages: English, Spanish, Portuguese, Arabic, Japanese, Ukrainian, and Swedish. Each technique and Library article is tagged with an evidence grade — strong, moderate, emerging, or contested — based on peer-reviewed research from sources such as PubMed, NIH, Stanford, and Harvard Health. An AI breathing coach helps users choose the right technique for their goal. The landing page at brizzy.app includes a technique comparison with Calm and Headspace, user testimonials, and a full evidence methodology section. iOS and Android apps are coming soon.

## Library

Reference-grade evidence reviews of individual breathing techniques. Each article covers how to practice it, the science with cited research, honest benefits and limits, safety notes, and when to use it. Evidence grade uses the Brizzy scale: strong (robust, replicated trials), moderate (solid evidence with some gaps), emerging (early or low-volume signal), contested (claims that conflict with the data).

- [Cyclic Sighing](https://brizzy.app/en/library/cyclic-sighing): A double inhale through the nose plus a long exhale through the mouth. Five minutes a day for four weeks reliably calms the body, with a smaller, less certain lift in mood. Evidence grade: moderate — rests on a single 2023 Stanford RCT, not yet independently replicated.
- [Box Breathing](https://brizzy.app/en/library/box-breathing): Equal-ratio inhale–hold–exhale–hold cycle (3–6 s per phase), also called tactical or square breathing. How to choose the interval, the science of slow rhythmic breathing, and use cases from military to workplace. Evidence grade: emerging — the slow-breathing mechanism is supported, but this exact equal-phase protocol has not been tested in large trials.
- [4-7-8 Breathing](https://brizzy.app/en/library/4-7-8-breathing): Dr. Weil's extended-exhale pattern (inhale 4, hold 7, exhale 8). The long exhale shifts the body from alert to calm via the parasympathetic nervous system. Step-by-step for sleep and anxiety. Evidence grade: moderate.
- [Coherent Breathing](https://brizzy.app/en/library/coherent-breathing): A slow, even rhythm at about 5–6 breaths per minute (resonance-frequency breathing). The science of HRV and vagal tone, and where the evidence for stress, blood pressure, and sleep is solid or mixed. Evidence grade: moderate.
- [Oxygen Wave](https://brizzy.app/en/library/oxygen-wave): A cyclic-hyperventilation technique rooted in Tibetan Tummo and popularized by Wim Hof — power-breathing rounds with breath-hold retention for energy, adrenaline, and cold tolerance. Includes safety warnings. Evidence grade: moderate.

## Techniques

In-app guided sessions. Four breathing methods, each suited to a different goal, with a visual pacer and optional voice coaching:

- [Box Breathing](https://brizzy.app/app/technique/box): Equal-ratio inhale-hold-exhale-hold cycle (3–6 s intervals). Used by Navy SEALs and first responders for focus and calm under pressure. Emerging evidence. Beginner-friendly.
- [4-7-8 Breathing](https://brizzy.app/app/technique/4-7-8): Extended exhale pattern (inhale 4, hold 7, exhale 8). Activates the parasympathetic nervous system. Recommended for sleep onset and anxiety. Moderate evidence.
- [Coherent Breathing](https://brizzy.app/app/technique/coherent): Slow rhythm at ~5.5 breaths per minute to maximize Heart Rate Variability (HRV). Moderate evidence for nervous system balance. Beginner-friendly.
- [Oxygen Wave](https://brizzy.app/app/technique/oxygen-wave): Controlled hyperventilation rounds with breath-hold retention. Boosts energy, adrenaline, and cold tolerance. Moderate evidence. Intermediate — requires safety awareness.

## Use Cases

Goal-based quick sessions — direct links an LLM can recommend when a user describes a problem:

- [Stress Relief](https://brizzy.app/app/case/stress-relief): 5-minute box breathing session to lower cortisol. For: "I'm stressed", "I need to calm down."
- [Better Sleep](https://brizzy.app/app/case/better-sleep): 10-minute 4-7-8 session to transition into sleep. For: "I can't fall asleep", "bedtime breathing."
- [Power Up](https://brizzy.app/app/case/power-up): 3-minute Oxygen Wave session for energy and alertness. For: "I'm tired", "need a quick energy boost."
- [Calm Over Anxiety](https://brizzy.app/app/case/calm-over-anxiety): Deep 4-7-8 session for acute anxiety and grounding. For: "I'm having a panic attack", "anxiety breathing exercise."

## About

- [About Brizzy](https://brizzy.app/en/about): The story behind Brizzy and the team building it.
- [Safety Guidelines](https://brizzy.app/en/safety): When not to practice, when to stop, medical disclaimers. Important for health-related recommendations.
- [For Organizations](https://brizzy.app/en/for-organizations): Branded breathing experiences, coaching, research collaborations for teams, universities, and sports organizations.

## Optional

- [Evidence Library](https://brizzy.app/en/library): All published breathing techniques and evidence reviews.
- [Pricing](https://brizzy.app/en/pricing): Free plan and Plus upgrade. No time-limited trial; free is permanent.
- [Contact](https://brizzy.app/en/contact): Support, partnerships, feedback. Response within 1–2 business days.
- [Terms of Service](https://brizzy.app/terms): Legal terms.
- [Privacy Policy](https://brizzy.app/privacy): Data handling and privacy practices.