PDF Fixer is described as 'free PDF repair utility which fixes corrupt PDF files by restructuring the damaged PDF data, rebuilding XREF tables and then recovers those PDF documents back. It can repair PDFs which PDFTK & Ghostscript cannot repair'. There are more than 10 alternatives to PDF Fixer for Windows, Mac, Linux and BSD. The best alternative is QPDF, which is both free and Open Source. Other great apps like PDF Fixer are Stellar Repair for PDF (Paid), SysTools PDF Unlocker (Paid), PDF Password Remover Tool (Free) and A-PDF Restrictions Remover (Paid).
Kernel for PDF repair is highly advanced pdf file recovery software integrated with an extremely user-friendly Graphical user interface. The software provides instant and effortless recovery of data from the PDF file that seemed inaccessible or corrupt.
PDF User/Open password can prevent unauthorized persons from opening and viewing the password-protected PDF files. Sometimes you may forget the PDF User/Open password you set. In addition, some PDF documents you download may be password protected.