How to Use CPAP Clarity: A Complete Guide

From SD Card to Insights in 60 Seconds

Your CPAP machine collects incredibly detailed data every single night: pressure levels, leak rates, respiratory events, breathing patterns. The problem is getting to it. Your machine's screen shows a single AHI number. The myAir app gives you a simplified score. Neither one shows you the full picture. (If you've been using OSCAR, CPAP Clarity gives you a similar depth of data with a simpler interface.)

CPAP Clarity does. It reads your raw SD card data and turns it into clear, actionable insights, all in your browser, all for free, with your health data never leaving your device.

CPAP Clarity supports ResMed AirSense 10, AirSense 11, AirCurve 10 (AutoSet, CPAP, VAuto, ASV, ST), the AirCurve 11 ASV, the BMC E-20A AutoCPAP, the BMC G3 A20 AutoCPAP, and the React Health Luna G3. Here's how to get started.

What You Need

Three things to get started:

1. Your CPAP's SD card. Most machines come with one pre-installed and recording data every night, but not all. Some ResMed AirSense 11 units ship with a "dummy" training card that doesn't actually record, and refurbished or loaner machines may arrive without a card at all. If yours isn't recording, any standard SD card will work: see our SD card buyer's guide for recommendations and how to format a fresh one.
2. A way to connect the card to your computer. Most laptops have a built-in SD slot. If yours doesn't, a USB card reader (opens in new tab) is inexpensive.
3. A computer or Android phone with Chrome. CPAP Clarity runs entirely in your browser.

Don't have your SD card handy? You can try CPAP Clarity with sample data right now. The demo loads a realistic session so you can explore the dashboard, insights, and reports before importing your own data.

Step 1: Find Your SD Card

Your ResMed machine stores therapy data on a standard SD card. You'll need to remove it briefly to import your data.

ResMed AirSense 11: Look on the left side of the machine for a small hinged door. Open it and gently push the SD card inward. It'll click and spring out slightly. Pull it the rest of the way with your fingers.

AirSense 10: The SD card slot is on the right side behind a small flip-open door. Same push-to-eject mechanism.

AirCurve 10: The slot is on the back panel. Same push-to-eject mechanism.

Don't worry about removing the card. Your machine continues recording to its internal memory while the SD card is out. Just remember to put it back when you're done so the next night's data gets saved to the card. For a complete walkthrough of what files are on the card and how to handle it, see our CPAP SD card guide. For phone-based import, see How to Import CPAP Data on Your Phone.

Not sure which SD card or reader works with your machine? Our SD card buyer's guide covers card types, sizes, and reader recommendations. If your card isn't working, see our SD card troubleshooting guide.

Step 2: Import Your Data

Open cpapclarity.com in your browser. You'll see the import area front and center.

Option A: Drag and drop. Open your SD card in your file browser and drag the entire SD card folder onto the import area on the page. This gives CPAP Clarity both your therapy data (in the DATALOG folder) and your machine settings (model, mode, pressure, EPR), so you get the most complete analysis.

Option B: Browse. Click the "Browse" button and navigate to your SD card. Select the SD card's root folder and confirm.

CPAP Clarity will read your files and process the data. This usually takes just a few seconds, even for months of recorded sessions.

About your privacy: All processing happens entirely in your browser using JavaScript. Your CPAP data is never uploaded to any server. There's no account to create, no cloud sync, no data collection. Your health information stays on your device. Period. Learn more about our privacy approach in CPAP Data Privacy.

Step 3: Read Your Dashboard

Once your data loads, you'll see your most recent night's session on the dashboard. Here's what you're looking at:

The AHI Donut. This is your headline number, displayed prominently in the session card. It shows your Apnea-Hypopnea Index, the number of breathing disruptions per hour. The donut breaks down your events by type (obstructive, central, hypopnea) so you can see not just how many events you had, but what kind they were. The number is color-coded: green means excellent control, and warmer colors indicate higher levels that deserve attention.

Night Summary. Next to the AHI donut, you'll see a plain-English narrative describing your night. Something like: "You had an excellent night. Your machine recorded 2 breathing events, which is a very low number. Your mask seal was excellent overall." This summary interprets your data for you so you don't have to decode numbers.

Machine Settings. If you imported the whole SD card folder, you'll see a card showing your machine's configuration: device model, therapy mode, pressure range, EPR level, mask type, humidity settings. This is the same information your sleep physician sets up on your machine, and it's helpful context when reviewing your data.

Metric Gauges. Below the session card, three gauges show your key therapy metrics:

Metric	What It Tells You
Usage	How long you wore your mask (target: 4+ hours for insurance compliance, 7+ is excellent)
Leak Rate	How well your mask sealed (lower is better, under 24 L/min is good)
Pressure	The air pressure your machine delivered, in cmH2O

Each gauge shows your value with a color-coded rating (Excellent, Good, Moderate, etc.), a visual range indicator, and a comparison to your personal average. You don't need to memorize normal ranges; the gauges do the interpretation for you.

Event Breakdown. When events occurred, this section shows exactly how many of each type: obstructive apneas, central apneas, and hypopneas. Understanding the breakdown matters because different event types have different causes and solutions. See Central vs Obstructive Apnea for what the distinction means.

Charts. Scroll further to see time-series charts showing how your pressure, leak rate, and other signals changed throughout the night. The event timeline shows exactly when breathing events occurred, so you can correlate events with leak spikes, pressure changes, or body position shifts. If your machine detected Cheyne-Stokes respiration (a cyclic breathing pattern), those episodes appear as separate rows in steel blue.

Flow Limitation. Your machine records a flow limitation index every 2 seconds. This chart shows how restricted your airflow was throughout the night. Elevated flow limitation can fragment sleep even without scored apnea events, which is why some people feel exhausted despite a normal AHI. See Understanding Flow Limitation for more detail.

Step 4: Understand Your Insights

Scroll down to the insights section. This is where CPAP Clarity translates your numbers into plain English.

Instead of wondering what a leak rate of 28 L/min means, you'll see something like: "Mask seal could be tighter", telling you your leak rate is elevated and suggesting you check your mask fit. Visit our leak fix guide for practical solutions.

If your events are primarily central apneas rather than obstructive, you'll see: "Mostly central events", explaining that these are labeled as central (brain-signaling pauses, not airway collapse) and that the treatment approach may differ.

Each insight is prioritized by importance. The things that matter most appear first. Short sessions under 2 hours are recognized as naps and won't trigger false compliance warnings.

Step 5: Browse Your History

Click History in the navigation bar to see your therapy over time. This is where patterns emerge that single-night views can't reveal.

The centerpiece is your Therapy Score, a number from 0 to 100 that combines four dimensions of your therapy:

Component	Weight	What It Measures
AHI Control	40%	How well your therapy controls breathing events
Usage Hours	30%	Whether you're wearing your mask long enough
Mask Seal	20%	How consistently your mask maintains a good seal
Nightly Consistency	10%	How steady your therapy is from night to night

Track your score over weeks to see the trajectory. A rising score means your therapy is improving. A dipping score helps you catch problems early, before they become habits.

Trend Charts show your AHI, leak rate, and usage plotted over time. You can filter by 7 days, 30 days, 90 days, a year, or all time. Look for patterns: is your AHI creeping up? Did a mask change reduce your leak rate?

Comparison View. Mark a date (like when you changed masks or adjusted pressure) and see your before-and-after averages side by side. This makes it easy to measure the impact of changes to your therapy.

Step 6: Download Your Report

CPAP Clarity generates a comprehensive PDF report you can save, print, or share with your doctor. From either the dashboard or history page, click "Download Full Report".

The report includes your AHI breakdown by event type, key metrics with ratings, time-series charts, and a plain-English narrative summary. It's formatted for clinical review so your sleep physician can quickly scan and act on the data. Learn more about what to bring to your sleep doctor visit.

Step 7: Export for AI Analysis

Want deeper analysis? Click "Copy all nights for AI" on the dashboard or history page to copy your therapy data to the clipboard in a structured, plain-text format. Paste it into ChatGPT, Claude, or any AI assistant and ask questions like "what changed in my therapy after I got the new mask?" or "why has my AHI trended up over the last month?". The export includes nightly AHI, usage, leak, pressure, event counts, machine settings, and any manual nights you've marked, but it never leaves your device until you choose to paste it somewhere.

Size cap: the export is capped at the most recent 365 nights (roughly one year) to stay under typical clipboard and AI message limits. If you have more than a year of stored nights, the button label changes to "Copy last year for AI" and the oldest nights past the cap are left out of the paste. Your full history stays intact in the browser; only the copied snapshot is trimmed.

Step 8: Back Up and Manage Your Data

Click Data in the navigation bar to open the data hub. Everything that isn't part of your nightly review lives here.

Back up your data. Because CPAP Clarity keeps everything in your browser, clearing your browser storage, switching computers, or having iOS evict the site can all wipe your history. The Back up your data card lets you download a single .zip file containing every session, event, and machine setting. Save it to iCloud Drive, Google Drive, or an external hard drive. Restore it later on any computer or browser with one click. Nothing uploads to our servers.

Mark manual nights. Used a travel CPAP or forgot your SD card? Click Mark manual nights and pick the dates. Your consistency score stays accurate instead of breaking a streak on a night you actually slept on CPAP.

Storage usage. A small panel shows how much browser storage CPAP Clarity is using and whether any sessions are eligible for automatic cleanup. Sessions less than 90 days old are always protected.

Advanced data controls (collapsed by default): delete individual sessions, remove everything older than 90 days, or clear all data. Every destructive action asks for confirmation first, and your SD card is never touched.

Try It Now, No SD Card Needed

Not ready to import your own data? No problem. On the homepage, click "Try with sample data" to load a realistic demo session. You'll see exactly how the dashboard, insights, and reports work, so when you're ready to plug in your SD card, you'll know exactly what to expect.

Common Questions

What if I don't have an SD card reader? Most laptops have a built-in SD card slot on the side or front edge. If yours doesn't, a USB card reader (opens in new tab) is inexpensive and plugs into any USB port. See our SD card buyer's guide for specific recommendations.

Can I use CPAP Clarity on my phone? On Android, yes. Connect your SD card to your phone using a USB-C card reader, then open CPAP Clarity in Chrome and import normally. On iPhone and iPad with iOS 17 or later, Safari supports the same folder upload flow via a USB-C or Lightning SD card reader. See our phone import guide for step-by-step instructions.

Do I need to import every night? No. Your SD card accumulates data automatically. Import whenever you want to check your data: weekly, monthly, or before a doctor's appointment. CPAP Clarity reads the entire card each time, so you always get your full history.

What devices does CPAP Clarity support? ResMed AirSense 10, AirSense 11, AirCurve 10 (AutoSet, CPAP, VAuto, ASV, ST modes), the AirCurve 11 ASV (Adaptive Servo Ventilation), the BMC E-20A AutoCPAP, the BMC G3 A20 AutoCPAP, and the React Health Luna G3. More devices are on the roadmap. If you have a different machine, let us know so we can add support.

Your Data, Your Control

CPAP Clarity exists because your therapy data belongs to you, and understanding it shouldn't require a medical degree or complex desktop software. Whether you're preparing for a doctor's appointment, tracking your progress, or just curious about what happens while you sleep, your data is waiting on that little SD card.

Pull it out. Drop it in. See what your CPAP has been recording.

Start analyzing your CPAP data →

Some links in this article are Amazon Associates affiliate links. As an Amazon Associate I earn from qualifying purchases at no extra cost to you. See our full disclaimer.