TFF is a seldom used filename extension associated with Unix program IDOLON. TFF extension is commonly used by font files and should not be confused with IDOLON files with that same suffix. IDOLON is a niche program for fractal image analysis.

TFF files were popular on Sun system platforms. TFF files store tagged images generated as a result of mathematical analysis of a source 2D image. The tool was developed by a German company and released in 1996.