This tool will compute a Chaos game Representacion (CGR) image as described by Jeffrey (1990). When size of CGR image is not specified (Auto), the following image sizes are used:

  256x256 images for sequences up to 100,000 bp,
  512x512 images for sequences up to 1,000,000 bp,
  1024x1024 images for sequences up to 5,000,000 bp.
  For longer sequence, contact us.

An open source PHP program to generate GCR images is available here

Jeffrey,H.J. (1990) Chaos Game Representation of gene structure. Nucleic Acids Research. 18:2163-2170. PubMed