EDF & BDF Viewer

Open EDF and BDF recordings on iPad and Mac. Browse every channel, tap to read exact values, and inspect the full file header.

EDF & BDF Viewer opens biosignal recordings stored in the European Data Format (EDF, EDF+) and the BioSemi Data Format (BDF) — the file formats used across sleep, EEG, ECG and electrophysiology research.

One app for iPad and Mac. No installer, no Java, no Python environment, no account. Open a file and look at your data.

VIEW YOUR RECORDING • All-Channels montage — every channel stacked in one scrollable view. • Channel browser showing sample rate and physical unit at a glance. • Min/max envelope rendering, so a spike is never lost to naive decimation the way simple downsampling loses it. • On iPad, pinch to zoom and swipe horizontally with two fingers to move through time. On Mac, swipe with two fingers on a trackpad, drag, or use ⌘+, ⌘- and the arrow keys. • Tap anywhere to place a measurement cursor and read the exact time and amplitude at that point. • Fixed amplitude scales as well as auto-fit, so a quiet stretch and a loud one can actually be compared instead of both filling the pane. • Time and amplitude grid with labelled axes.

KNOW WHAT IS IN THE FILE • A full header inspector: format and version, start date and time, record layout, and every signal's sample rate, physical unit, physical range and digital range. • Correct digital-to-physical calibration for both 16-bit EDF and 24-bit BDF.

OPEN FILES FROM ANYWHERE • Open in place from the Files app on iPad, or double-click in the Finder on Mac. • Drag a recording onto the window. • Recent files reopen without hunting for the folder again. • A synthetic demo recording is built in, so there is something to look at before you have a file of your own.

PRIVACY No accounts, no analytics, no network features of any kind. Files you open never leave your device, and the developer cannot see them.

IMPORTANT EDF & BDF Viewer is a file-viewing utility for research, educational, and engineering use. It is not a medical device and is not intended for diagnosis, treatment, or any clinical decision-making.