A Free Ultra Fractal Alternative in Your Browser

Ultra Fractal has been the reference program for fractal art for a long time. It runs on Windows and macOS, it is sold as a paid license, and its current major version is Ultra Fractal 6. Its central idea is that a fractal image has independent parts: a formula, transformations applied to the plane, a coloring algorithm, and a gradient, with layers stacked and blended on top.

Fractal Zoom Studio, the free tool behind these guides, was built on that same separation. It runs in a browser tab, needs no install or license, and aims at a narrower job: geometric patterns and tilings, seamless loop video, and output for print, CNC, and laser work. This page covers what carries over from Ultra Fractal, what doesn't, and when each one fits.

◆ Open in StudioOpen Ray Vortex, a two-layer transform stackAngular rays, then ripples, then a {7,3} hyperbolic fold. Toggle each layer under Operators to see what it adds.

The shared model: formula, transforms, coloring, gradient

Anyone coming from Ultra Fractal will recognize the structure of the Effects panel:

• Source (the formula). Mandelbrot, Julia, and several geometric fields: linear bands, rings, angular rays, polygon distance, a quasicrystal wave field, and a de Bruijn multigrid.
• Operators (transformations). Up to eight layers applied to the plane in order before the formula runs: Kaleidoscope, Spiral Warp, Twist, Mirror, Inverse, Ripples, Rotate/Scale, Hyperbolic Tiling, Log Spiral Tiling, and Penrose Substitution. Each layer can be toggled and reordered.
• Coloring. Smooth bands, a distance-estimation field, and ring and cross orbit traps.
• Gradient. Draggable color stops, density, rotation, and a separate interior color. Changing the gradient never recalculates the fractal, so recoloring is instant.

The main difference is what "layer" means. In Ultra Fractal a layer is a full fractal image with its own formula and coloring, blended with the others through merge modes and masks. Here there is one source per scene, and the layers are transforms stacked on its coordinates. That covers a lot of Ultra Fractal-style composition, such as a twisted, kaleidoscoped Julia set with trap coloring, but it cannot blend two different fractals into one image.

◆ Open in StudioOpen the orbit-trap Julia compositionSwitch Coloring between Smooth bands, Distance field, the orbit traps, Stripe average and Triangle inequality. The shape stays put while the rendering changes.

Side-by-side comparison

	Ultra Fractal 6	Fractal Zoom Studio
Price	Paid license (watermarked evaluation copy)	Free
Platform	Windows and macOS desktop app	Any browser with WebGL2, no install
Formulas	Many built in, plus thousands in the online formula database	18 built-in sources (fractals, curves, tilings, patterns)
Custom formulas	Yes, in its own formula language	No
Image layers	Yes, with masks, groups, and merge modes	No, one source per scene
Plane transformations	Yes, from built-ins and the formula database	16 types incl. 17 wallpaper groups, up to 8 stacked
Coloring algorithms	Many, plus user-written ones	Smooth, distance field, 2 orbit traps, stripe average, triangle inequality, tile edges
Gradient editing	Yes, very detailed	Stops, density, rotation, interior color
Deep zoom	Effectively unlimited, with perturbation speed-ups	Limited to about 10^4 to 10^5x (single precision)
Animation	Any parameter, any length and frame rate	Loop tracks that always close seamlessly
Tilings (Penrose, hyperbolic, spiral)	Possible through community formulas	Built in
Still export	Yes, very large renders	PNG up to 8K and 300 DPI print sizes
CNC / laser output	No built-in heightmap or vector export	16-bit heightmap, STL, SVG contours
Sharing a scene	Parameter files	The URL holds the full state

Where Ultra Fractal is still the better tool

Be clear about this before switching. Ultra Fractal is the stronger program for several kinds of work:

• Deep zooms. It uses arbitrary precision, and version 6 added perturbation calculations that bring renders which used to take hours down to minutes. The browser tool calculates on the GPU in single precision. Escape-time fractals start to break into blocks at roughly 10,000x to 100,000x magnification, well short of the zooms people post from desktop software.
• Formula variety. Ultra Fractal ships with a large formula set and connects to an online database of thousands of formulas and coloring algorithms from its users. You can also write your own. The browser tool has a fixed list.
• Layered compositing. Masks, merge modes, and many stacked fractals are how a lot of Ultra Fractal art is made. There is no equivalent here.
• Free-form animation. Ultra Fractal animates any parameter along any path for any length. The loop engine here is intentionally narrower (see below).

The distance-field demo shows the zoom limit directly. It opens on Seahorse Valley with distance-estimation coloring, which stays crisp across a wide range of zoom. Keep scrolling in and the filaments eventually turn into blocks. That is the single-precision floor.

◆ Open in StudioOpen Seahorse Valley with distance-field coloringDistance estimation keeps thin filaments sharp. Scroll in to find where precision runs out.

For more on why distance estimation produces those sharp filaments, see The Mandelbrot Set, Explained Visually.

Where the browser tool fits better

No install, no license, any device. A link opens the exact scene, including source, transforms, colors, and animation. That makes it easy to send a design to someone else, or to use on a Linux machine or Chromebook where Ultra Fractal doesn't run.

Patterns and tilings are built in. Penrose substitution, hyperbolic {p,q} tilings, log spiral (Droste-style) tilings, quasicrystal interference, and multigrid webs are one click each. In Ultra Fractal these are possible, but they depend on finding and learning the right community formulas. See the Penrose tiling guide and the cool fractals gallery for examples.

Loops that close by construction. Each animation track runs a whole number of cycles per loop: rotations make full turns, gradients flow one full period, and scalar values swing out and back on a sine curve. The last frame therefore matches the first without keyframe tweaking, and the MP4 export repeats cleanly on social feeds and screens.

◆ Open in StudioOpen a seamless Julia morph loopThe seed traces a figure-eight and returns to its start. Export it from the Motion section as an MP4.

Output for making things. Along with MP4 loops, the export options cover:

• Still PNG up to 8K, plus 300 DPI print sizes for wall art. The image is rendered again at full size rather than enlarged from the screen.
• Heightmaps as 16-bit grayscale PNG, and STL meshes, for CNC relief carving, 3D laser engraving, and 3D printing. The height comes from the fractal's own value at each pixel, not from the brightness of the colors.
• SVG contours that trace the color bands as vector paths for laser scoring or a pen plotter.

Finish effects. Ordered dithering, palette reduction, pixelation, grain, and RGB split run as a final pass. They're covered in the guides to ordered dithering and pixel-art filters.

Which one should you use?

Use Ultra Fractal if you want deep zooms, write or collect formulas, or build images from many blended layers. It remains the more capable program, and the evaluation version lets you try all of it before paying.

Use the browser tool if you want geometric fractal patterns, kaleidoscopes, and tilings, a seamless loop for video, or a print, heightmap, or cut file, and you would rather not install anything. Plenty of people will use both: Ultra Fractal for deep exploration, and the browser for pattern design and output.

A good first step is the fractal kaleidoscope guide, which walks through one transform in detail, or the Julia set guide for the escape-time side.