FXS is a rare format associated with files sent or received through Winfax, a program that allowed computers using the Windows platform to communicate with fax machines through a modem. An FXS file most likely contains the image of a document that was sent or received by fax, using this software. Winfax was discontinued in mid 2000s and FXS files are currently uncommon and obsolete.
The quick and simple way to handle your files is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch conversions. As you will soon realize, reaConverter will help you avoid spending countless hours trying to figure out how to convert multiple FXS files as once.
JPEG JPG PNG GIF TIFF TIF BMP ICO EMF WMF AI PDF EPS PS EPI WEBP WEBPLL JP2 PCX TGA DWG DWF DXF DGN WMZ CGM DRW GBR PCT MIF PLT PCL SVG WPG CIN DCX DIS HRU MTV PRC RAD PIC RLA QRT SGI XBM XPM SWF CAL FAX FITS PSD PGM JXR BPG APNG DDS SVGZ CG4 FLIF