How to Generate a Random SVG Blob Shape
Published September 15, 2026 · 2 min read
Those smooth, organic blob shapes behind hero sections and illustrations aren't drawn by hand — they're generated from randomized points connected with a smooth curve. This tool builds one from a seed value, so the same seed always reproduces the same shape.
Try SVG Blob GeneratorSteps
- 1
Open the SVG Blob Generator
Go to the blob generator.
- 2
Set the anchor points and randomness
More points create more complex shapes; higher randomness creates more irregular, organic outlines.
- 3
Pick a seed and color
The seed determines the exact shape — change it for a new blob, or keep it to reproduce the same one later.
- 4
Copy the SVG
Use the generated markup directly in your HTML or design tool.
Frequently asked questions
Yes — the generator is fully deterministic, so a given seed and point count always reproduces the exact same blob, useful if you want to recreate a shape you liked later.
The randomized points are connected using a Catmull-Rom spline converted to smooth cubic Bezier curves, which is what gives the blob its organic, rounded outline rather than sharp angles.
Yes — that's a common use case; copy the SVG and position it behind your content with CSS, adjusting the fill color to match your design.
Because the shape is real, editable SVG markup — not an image — it scales perfectly to any size without any loss of quality.