About converting .sav to CSV
CSV is the universal exchange format for tabular data: every spreadsheet program, statistics package, and programming language reads it. Converting here keeps your rows and columns intact while dropping the proprietary wrapper, so the data opens anywhere.
SPSS stores more than raw numbers. A .sav file carries variable labels (the human-readable description of each column), value labels (the text behind codes like 1 = "Strongly agree"), declared missing values, and date formats. statfile.tools reads all of these. When you export, you decide whether coded categories should appear as their numeric codes or their labels, and whether dates should be written as readable ISO timestamps.
Because the parser is built from the ground up to run in the browser, there is no file-size cap imposed by an upload step and no queue. Open-source tools like ReadStat and pandas can do the same conversion offline, but they require installing software and writing code. This page gives you the same result with a single drag-and-drop, which is why it suits anyone who has been handed a .sav file but does not own SPSS.