What CPAP Clarity does

Every modern CPAP machine writes a detailed log to its SD card every night. Manufacturers surface a fraction of that data through their summary apps. CPAP Clarity reads the raw card directly, parses it client-side in your browser, and shows you everything your machine recorded in plain English. Optionally layer in a Wellue pulse oximeter for overnight oxygen, or an Oura Ring or Apple Watch for sleep stages and heart-rate variability. Everything joins by date so a rough night with high ODI shows up against the same calendar as your AHI. No account, no upload, no subscription.

Every number your machine records, explained

• AHI (apnea-hypopnea index): events per hour. Under 5 is well-controlled; 5 to 15 is moderate residual; above 15 warrants a conversation with your sleep clinic. CPAP Clarity also splits AHI by event type (obstructive, central, hypopnea) so a rising AHI tells you which kind of event is driving it.
• Mask leak: how much air is escaping. ResMed flags 24 L/min as the threshold above which leak compensation can no longer keep delivered pressure on target. Persistent high-leak nights mean the machine thinks it is treating you, but the air is bypassing your airway.
• Pressure: average and 95th-percentile pressure delivered, in cmH₂O. Auto-titrating machines move pressure during the night; the P95 number is what your sleep clinic looks at. We also surface the implied exhale pressure when EPR is on.
• Usage: nightly therapy hours, plus a 70%/4-hour insurance compliance check on the compliance tracker page.
• Therapy score: a single 0 to 100 number that combines AHI, usage, leak, and consistency. It is plain English ("Solid night," "Worth a closer look"), not a clinical measurement.
• Flow limitation, snore, respiratory rate, tidal volume: the breathing-pattern signals OSCAR users care about. Surfaced where supported by the device. Available on ResMed, Luna G3, and Löwenstein Prisma; format-bounded on BMC and AirCurve 11 ASV (the machine itself does not log certain channels).
• Overnight oxygen (with a Wellue O2 Ring, OxySmart, O2Ring S, O2Ring 5103, or Checkme O2 Max): mean and minimum SpO2, ODI (3% and 4% drop rates on scoreable overnight recordings), time spent under 88%, and a per-night desaturation timeline. Joins by date to your CPAP nights so a rough AHI window can be cross-checked against actual blood-oxygen events instead of inferred from breathing pattern alone.
• Sleep stages and recovery signals (with an Oura Ring, Apple Watch, or Fitbit): deep / light / REM minutes, heart-rate variability, resting heart rate, body temperature deviation, and SpO2 on supported models. Drop the Oura account-export ZIP, the Apple Health export.zip, or your Fitbit Google Takeout folder straight into the same import zone; the wearable streams sit alongside the CPAP data on the dashboard.

How it compares to the alternatives

myAir(ResMed's app) gives you a 0 to 100 score and 30 days of summaries. It hides event type breakdowns, full leak time series, pressure curves, and respiratory-rate data. It is also ResMed-only.

OSCAR is the open-source desktop tool many advanced users run. It is more powerful than CPAP Clarity in some ways (per-second flow waveforms, custom layouts), but it is desktop-only, has a steep learning curve, and is not friendly to first-time data-curious users. CPAP Clarity is positioned for the user who finds myAir too thin and OSCAR too much.

SleepHQ is a paid cloud service ($15/month) that stores your CPAP data on its servers. CPAP Clarity does the analysis side for free in your browser; the trade-off is no cloud sync between devices, but also no recurring fee and no one else holding your medical data.

None of the above join your CPAP data with a pulse oximeter and a sleep wearable in one view without an account or a cloud upload. CPAP Clarity joins ResMed, BMC, Luna G3, and Löwenstein nights to Wellue overnight SpO2 and to Oura, Apple Watch, or Fitbit sleep stages by date, all in your browser, so you can see a high-AHI window against the same night's ODI and REM minutes without exporting to three different tools.

Privacy is the architecture, not a slogan

When you import an SD card, the parser runs as JavaScript inside the browser tab you are looking at. The parsed sessions land in your browser's IndexedDB. None of it leaves your computer. We cannot retrieve your data even if a court asked us to, because the data is not on our servers in the first place. The site has no user accounts, no backend database for therapy data, no cloud queue. Browser-only, private by design.

For the deeper architecture write-up, see how CPAP Clarity handles your data. For a walkthrough of the dashboard, history view, and PDF therapy report, see how to use CPAP Clarity.