When you click "Download Dat file," check the browser preview. If the first line is just numbers (e.g., 1.000000 0.000000 ), it’s Selig format — the most universal.
| Format | Header | Example Software | | :--- | :--- | :--- | | | No header, starts with coordinates | XFLR5, Xfoil, QBlade | | Lednicer | Has a title line and chord info | DesignFOIL, some CAD plugins | | TXT (Space-separated) | May have comments ( # ) | MATLAB, Python (Pandas), SolidWorks | download dat file from airfoil tools