To read OST file for free, you can avail the freeware demo version of the Recover OST file software which is the best way analyzing the Repair OST file software. OST Recovery application is absolutely dependable for repairing offline folder data. But even then, if you want to know the reliability level and functionalities of the software prior to purchase, getting the trial version is apt.
The trial will demonstrate the Convert OST file to PST software working entirely but will restrict you while saving the repaired data as PST. Hence, you can read OST file, and ensure the software working confidently.