Convert EyeLink EDF to ASC with Python: A Reliable Workflow When the Converter Won’t Open

If you work with EyeLink eye-tracking data, you’ve likely faced the moment when analysis depends on a simple step: converting EDF files into ASC. ASC is convenient because it is human-readable and easy to parse for messages, events, and sample streams. In many workflows, it is the first step before preprocessing, quality checks, synchronization, or importing into analysis scripts.

In my case, that step became the bottleneck. On my PC, the standard EyeLink conversion tool did not open or run reliably, which blocked everything downstream. Instead of spending more time on repeated troubleshooting, I built a small Python utility that calls the EyeLink converter from a script and performs the conversion in a reproducible way.

The idea is simple: point the script to a folder, and it converts each .edf file into a matching .asc file. It can also skip files that have already been converted, so you can safely rerun it as part of your pipeline. This is especially useful when you have multiple participant folders, repeated sessions, or large datasets that need consistent handling.

This tool is meant to be practical and easy to integrate. You can use it as a standalone helper when you just need ASC output quickly, or you can plug it into a larger preprocessing workflow so EDF-to-ASC conversion becomes a stable, automated step rather than a fragile manual task.

I’m sharing the full code, setup notes, and a minimal example in my GitHub repository. I will also mirror it in our lab’s GitHub repository

for collaboration and long-term access.

My GitHub profile: github.com/alparslanonder

My repository (EDF to ASC converter): github.com/alparslanonder/eyelink-edf-to-asc

Lab GitHub repository: github.com/kogneuro/eyelink-edf-to-asc