EDFbrowser is a free, open-source desktop application for macOS (and other platforms) that lets you open, annotate, and analyze biomedical time-series recordings stored in the EDF, EDF+, and BDF+ file formats — the data formats used by EEG, ECG, EMG, and polysomnography equipment worldwide.
What is EDFbrowser?
EDFbrowser is a specialized signal viewer built specifically for the EDF (European Data Format) family of biomedical recording files. If you work with overnight sleep studies, epilepsy monitoring, or cardiac telemetry, you already know the file format — and you already know how few good tools exist for exploring it on a Mac without spinning up a Linux VM or wrestling with MATLAB.
The application was written by Teunis van Beelen and has been actively maintained for well over a decade. It handles both EDF+ (the extended variant that supports annotations, discontinuous recordings, and reserved fields) and BDF+ (the 24-bit variant used by BioSemi ActiveTwo and similar high-density EEG systems). That coverage matters in practice: a single clinical research lab can generate all three sub-formats depending on which acquisition device they're running that week.
What does EDFbrowser do best?
EDFbrowser shines at raw signal inspection with low overhead — you can open a 24-hour polysomnogram on a mid-range MacBook and scrub through it at full resolution without converting or sub-sampling the file first. The waveform renderer is fast, the amplitude and time-scale controls are granular, and the annotation overlay (EDF+ TAL blocks) displays inline rather than in a separate panel.
- Multi-signal overlay: stack EEG, EOG, EMG, respiratory, and SpO2 channels side by side in a single scrolling view with independent gain per channel.
- Annotation editing: add, edit, and delete EDF+ annotations directly, then save back to the same file — invaluable for manual sleep staging or event marking.
- Signal processing pipeline: built-in filters (high-pass, low-pass, notch, band-pass), FFT power spectrum, and a signal average tool cover most pre-processing needs without leaving the app.
- Format conversion: export to ASCII/CSV, cut recordings into segments, or convert between EDF variants. The batch converter handles entire directories, which saves hours when harmonizing a mixed dataset.
- Header inspector: the patient info, recording metadata, and per-signal calibration values are a right-click away — critical when auditing files for regulatory submission.
I've used it to cross-check automated sleep-staging outputs against ground-truth PSG recordings, and the ability to jump straight to an annotation timestamp and expand the surrounding epoch is something I'd miss deeply if I switched tools.
Is EDFbrowser free?
Yes — EDFbrowser is completely free to download and use, with no registration, no trial period, and no feature paywalls. It is distributed under the open-source BSD-style license, and the source code is available on the author's site. On macOS you can install it via Homebrew Cask (brew install --cask edfbrowser) or download the native .dmg directly from teuniz.net.
Who should use EDFbrowser?
EDFbrowser is for clinical researchers, neurophysiologists, biomedical engineers, and data scientists who work with physiological time-series data — not casual users. If your day involves EEG montages, polysomnography scoring, or any workflow where a colleague hands you a .edf file and asks you to "just take a look," this is the tool you want installed.
It is emphatically not a general-purpose waveform editor or audio tool — don't reach for it to trim a podcast. But within its lane it has no real competition on macOS. Alternatives like Polyman or SleepTrip require MATLAB licenses that cost thousands of dollars annually. Browser-based viewers like BrainBrowser are convenient for sharing but lack the processing pipeline depth. EDFbrowser gives you the full toolbox for free, natively.
What are the best EDFbrowser alternatives?
The honest answer is that native-Mac alternatives are thin. Polyman (MATLAB-based) remains the gold standard in polysomnography scoring labs but is expensive and Windows-first. EEGLAB (also MATLAB) has richer source-analysis features for high-density EEG but demands significant setup time. For quick signal review only, the MNE-Python library offers a scriptable viewer, though it requires a Python environment and is not a point-and-click tool. If you simply need to share a recording with a clinician who doesn't have any software, the web-based EDFbrowser Online viewer (a separate project) works in a browser but cannot write annotations back. For anyone who needs a full offline toolbox at zero cost, nothing on macOS currently beats the desktop EDFbrowser.
Does EDFbrowser run natively on Apple Silicon?
The Homebrew Cask build runs under Rosetta 2 on Apple Silicon Macs, which means launch is slightly slower than a native ARM binary but day-to-day performance — including scrubbing through large recordings — remains responsive for most clinical file sizes. The author has published updated builds periodically; check teuniz.net for any ARM-native release that may have landed after your initial install.
