FileOptimizer is a file compression tool used to reduce a variety of file types without changing the quality, also known as "lossless" compression. This is done via wide variety of optimization tools and recompression techniques combined into one program. Original files are sent to the recycle bin for restoration in the event the uncompressed version is preferred. Formats include audio/video (MP3, OGG, OGV), image (GIF, JPEG, PNG), office formats (DOCX, XLSX, ODT, PDF), and system files (DLL, EXE).

FileOptimizer is a lossless file size optimizer supporting BMP, DIB, DLL, BPL, DRV, LZL, SYS, CHM, CHS, CHW, DOC, DOT, FPX, MDB, MDT, MIX, MPD, MPP, MPT, MSI, MSP, MST, ONE, OST, PPS, PPT, PUB, PUZ STICKYNOTES, SNT THUMBS, DB, VSD, VST, VSS, XL, XLC, XLM, XLS, XLW, XSF, XSN, EXE, SCR, GIF, GZ, TGZ, SVGZ, JNG, JPG, JPEG, MNG, MP3, OBJ, O, LIB, A, OGG, OGV, EPDF, PDF, APNG, ICO, PNG, SWF, FAX, TIF, TIFF, PTIF, PTIFF, WEBP, AIR, APK, APPX, CBZ, DOCM, DOCX, DOTX, DOTM, DWFX, EPUB, IPA, JAR, MPP, ODT, OXPS, PPAM, POTM, POTX, PPSM, PPSX, PPTM, PPTX, PUB, SLDM, SLDX, VDX, VTX, VSX, XAP, XLAM, XLSM, XLSX, XLTM, XLTX, XPS, ZIP, AAI, AVS, DCX, PCC, PCX, FITS, JP2, JPC, HDR, HRZ, MIF, MIFF, MTV, OTB, P7, PALM, PDB, PBM, PCD, PCDS, PFM, PGM, PICON, PIC, PICT, PNM, PPM, PSB, PSD, SUN, VICAR, VIFF, WBMP, XBM, XPM, and XWD file formats among others