While there is no permanent free version, Nitro offers a way to test their (Nitro Pro 14) at no cost:
: Even if you have an old installer, Nitro has shut down the activation servers for version 9. This means you cannot activate it, even with a valid serial number. Nitro pro 9 gratis
: The trial typically does not require payment information upfront. While there is no permanent free version, Nitro
: A lightweight Windows tool that offers extensive features for free, though some advanced tools will add a watermark to the saved file. Nitro pro 9 gratis
: Using older, unsupported software like version 9 poses security risks, as it does not receive patches for modern vulnerabilities.