Choosing a Fractal Generating Program

The purpose of this write-up is to help people choose a fractal generating program so that they can make wonderful fractals. Of the two hundred or so programs that are available on the Net, I have used about 20 different ones, with varying degrees of success. This page contains my recommendations and free program downloads both in the body and at the end.


One may assume that all fractal generating programs give the user one or more algorithms, the capability to zoom in and to save images to disk. So what distinguishes an excellent program from an average one?

I propose the following criteria, roughly in order of importance:

1) The richness and complexity of the images one can produce with the program. This applies to two major aspects of the images: a) form and b) colour.

         a) Richness of form. The program should enable you to produce complex patterns with rich detail. Above all, it should let you create images that have complex and interesting structure, as opposed to random-looking blotches. (Hands up all those bored with the familiar Mandelbrot split circle.)

         b) Richness of colour. It should use 24-bit colour (also called 'true colour') rather than 256 colours. 24-bit colour allows one to generate up to 16 million different colours. No single image is likely to be that chromatically rich, but one of my Tierazon images has more than 400,000 colours.

The program should create images whose colour varies continuously rather than discretely. It should produce a variety of colours and textures, as opposed to solid blocks of colour, dotty images, or silhouettes.

2) It should offer a variety of algorithms giving different types of fractals. The program should come with a fair number of built-in algorithms, or else allow you to specify your own. If y = z*z is the only available equation, even though this gives the incredibly rich Mandelbrot set, we are likely to lose interest before long.

3) The scope it gives for manipulating the images produced. This includes colour alteration, the use of filters to produce different effects (perhaps completely changing how the fractal looks) and other ways of manipulating the image.

4) Utility. It should be easy to use, intuitive and fast. 'Easy to use' is hard to define since whatever we are used to appears easy and natural. When we change to another program with a different user interface then this new program may initially appear 'difficult' to us. Thus a program that seems intuitive and easy to use to me may seem difficult to you, and vice versa. Also: is useful help available?

5) Cost. Unless the program is streets ahead of the free fractal generators available, there seems little point in forking out money for it, though you may be willing to put up with being nagged to register. There are many high-quality freeware programs.


Here are my views on some of the programs I have tried. All programs except fractint produce 24-bit images. Eight of the programs have been written by the amazing Stephen Ferguson. Thanks a million, Stephen!

Fractint v19.6
Produces chunky or pontillist-looking ('dotty') images in at most 256 colours. The images look crude compared to 24-bit ones. It is not easy to use and DOS-based. Colour manipulation is very awkward. It has many algorithms and you can generate your own, up to a point. It has good zooming-in controls (eg you can rotate the zoom window). It was a great program in its time but is now something of a museum piece.

Download the latest version for free: fractint, which I have not tried.

Tierazon v2.7 (or 2.8) ***
Produces a tremendous variety of rich images, with often spectacular colour. It has 117 built-in algorithms and you can easily specify your own. It has a rich array of filters that can completely change the look of the image. It has good colour altering controls. It has no help, but is easy to use (see my instructions). Tierazon has few bugs and runs fast. It is my second-favourite program, but this may be because I am most familiar with it, having made 9,979 fractals using it. The fact that I still have not exhausted it tells you a lot. Most of the fractals on this site were made using Tierazon 2.7. Tierazon is more subtle than ktaza or Sterling. It also allows you to make fractal movies by specifying the start and end of a zoom sequence - impressive stuff.

Ktaza v0.1 **
No program I know produces novel and interesting images as easily as ktaza. Colours tend to be brilliant and it has 48 built-in algorithms. Unfortunately, ktaza has quite a few bugs. Despite this, I recommend it strongly.

Sterling v1.7 ***
It has 50 algorithms and is overall a superb program and currently my favourite, together with Sterling2. It produces rich colour and interesting textures. Its only drawback is that it is not free, but see below...

Sterling2 v1.7 ***
It has 50 algorithms and is overall a superb program. It is the best free fractal generator in my opinion. It produces rich colour and interesting textures, giving rich effects. Sterling2 is identical to Sterling except that all its formulae are different. The zip file includes simple instructions. Room 20, Room 21, Room 22 and Room 23 showcase what can be done with the program. Sterling2 is free to download and use:

Download Sterling2 v1.7 Size = 436 Kbytes, free and highly recommended.

Visions of Chaos ***
This program allows you to make amazing three-dimensional fractals. It also allows you to make fly-overs into and through the objects it draws. These fractals are three-dimensional because, although they are two-dimensional pictures on the screen, they depict three-dimensional virtual objects that exist somewhere in mathematical space, in the same way as a perfect cube exists as a mathematical object. Making three-dimensional fractals is like photographing a sculpture, whereas making two-dimensional fractals is like photographing a painting. All the 3D fractals on my site were made using the Visions of Chaos program, which is available at Softology. The program is now free and I highly recommend it. I have written simple instructions for using the program.

You can download Visions of Chaos from Softology.

Vchira v0.05 **
This is another program that is well-worth trying.

Flarium v8.9 *
Is similar to tierazon in look, feel and capabilities. However, in my experience, it does not produce images that are as rich or as varied as Tierazon's. It is good at producing organic-looking shapes. It has 143 built-in algorithms and you can specify your own. It tends to produce yucky colour combinations.

Inkblot v2.7 **
As for Flarium, compared to which it is perhaps a little less versatile, though the colours are much more esthetic. It is less feature-rich than Flarium but produces more interesting images. It has 18 built-in algorithms and allows you to specify your own. Filters are limited.

Grafzvizion v4.2
Has 36 formulas but has not been debugged properly yet. I have not been able to make many interesting images with it. Somewhat slow. It has potential.

Iftp (or FTP) v0.4**
This program is intended primarily for physically and/or mentally disabled persons, and for children. Hence the user interface is a simple button lay-out on the 4 sides of the screen, with virtually no pop-up dialogues. The actual fractal generator is the same as for ktaza, only the GUI is different. Iftp works well with hands-free operation, ie voice-only control.

Note: If you become familiar with one of Stephen Ferguson's programs then you will find it easy to use the others. His works include Tierazon, Sterling, Ktaza, Inkblot, Flarium, GrafZVizion, Iftp, Vchira and Iterations. I am sure he holds the world record for the production of quality fractal generators. Most of the images on this site were made with one of his programs.

Ultrafractal v2.01
Has fairly good help and an interesting layering feature but only a small number of algorithms. Apparently you need to get plug-ins to get real value out of the program. There is a formula editor but I couldn't work out how to use it. Though Ultrafractal has a dedicated following the program is very complex and difficult to use. After considerable effort I have been unable to produce any good fractals using UF. It can also be maddeningly slow to draw an image. Being shareware, it politely asks you to register after 30 days. Despite, or perhaps because of all these drawbacks, UF is one of the most popular fractal generators. As for me, I've sworn never to use it again.

Download the latest version of the Ultrafractal shareware program. Size = 5 MB approx.

Dofozon v1.07
Seems to have good potential but nearly all the fractals I have made using it end up looking like coloured sausages. It's also rather slow.

Download the Dofozon 1.07 program for free. Size = 1.4 MBytes.

"Fractal Orbits" and "Brazil" are weaker than any of the above and are not recommended.

Postscript & Downloads

If the above confused you, then just download Sterling2 and start making amazing fractals within minutes. In order of preference, my favourites are: Sterling and Sterling2, Tierazon, Ktaza, Inkblot. Unfortunately, except for Sterling2, these programs are no longer freeware. You can purchase all of Stephen Ferguson's fractal programs by paying $35 US at: Stephen's site.

I know that some fractal makers violently disagree with parts of what I have written. I hope this little piece will open up a debate. If you want to let the world know about the virtues of your favourite program, please feel invited to do so.

If you want to see an exhausting listing of fractal programs click on Paul Lee's write-up. If that's too bewildering, have a look at a shorter software list.

Another good place to start is: Program Downloads

Of course there is nothing to stop you from looking for other free programs on the Net. Good luck! You can try doing a search for 'fractal' at a freeware listing or just google "fractal programs".

This page was created in 1999 and last updated on 29 November 2016.