What it does

XDF viewer and reader

Open .xdf files from LabRecorder and other LSL recorders, with one tab per stream. Big files are indexed once and stay fast to scroll and zoom. In the browser the file is read locally and never uploaded.

Live LSL stream viewer

Find the LSL streams on your network and view them live, with filters, re-referencing, power spectra, signal quality and trigger decoding.

Record and replay

Record LSL streams to XDF (as LabRecorder does), and replay an XDF recording as LSL streams in real time to test your pipeline without the hardware.

LSL over the internet

Share streams over a WebSocket bridge, view them in a browser, publish from a browser, or relay between browsers. Set up a bridge or relay.

Devices

OpenBCI Cyton (+ Daisy) and serial devices that print numbers (e.g. an Arduino): on desktop, on Android over USB, and in Chrome or Edge with WebSerial.

Command line

The lsl tool lists, records, shares, bridges, relays, replays and generates streams. It comes with each desktop release.

Get it

Web: open LSL Viewer in your browser. No install; XDF files, serial devices, and LSL through a bridge.
Windows, macOS, Linux, Android: from the releases page (lsl_viewer releases). The desktop archives also contain the lsl command line tool, which is also available on its own as lsl-cli-….
From source: flutter run in apps/lsl_viewer.

For developers

xdf

Read and write XDF files in pure Dart, on every platform including the web. It uses pyxdf's clock synchronisation, dejittering and defaults, and is tested against pyxdf.

liblsl

Dart and Flutter bindings for Lab Streaming Layer, with full parity with the C library (JOSS paper).

lsl_tools

Record to XDF, the WebSocket bridge and relay, test outlets, and the lsl command line tool.

Questions

How do I open an XDF file?

Go to the web app and choose Open recording…, or drop the .xdf file onto the window. On the desktop you can also pass the file on the command line.

Can I view LSL streams in a browser?

Browsers can't use LSL directly. Run lsl share (or Share or relay streams… in the desktop app) on the lab computer and connect to it from the web app. See the bridge and relay guide.

Is it free?

Yes. It is MIT licensed, with source on GitHub.