SYN is an old and obsolete image format also known as Synthetic Universe. It is similar in size and features with the SYNU format, and might be equally difficult to open via regular image viewers. In case you found or were sent such a file, it's probably best to convert it to a more accessible format before trying to open it.
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 SYN 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 SHP 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 AVIF QOI
Advanced users can convert SYN files via command-line interface in manual or automated mode. You are welcome to contact our technical support when you have any questions about reaConverter.