What is a blob shape used for in UI design?

As a soft background element behind illustrations, an avatar or image mask, or decoration on empty states and onboarding screens. It breaks up layouts that would otherwise be entirely rectangular.

Should I use SVG or PNG for a blob?

SVG. It stays sharp at every pixel density with no export variants, and you can recolour it with a single fill attribute when you need a dark-mode version.

Are the generated blobs free to use commercially?

Yes. The path is generated from your settings — there is no licence, no watermark and no attribution required.

floow.design

Blob Generator

Generate organic blob shapes as SVG, for backgrounds, masks and decorative fills.

Generate freeSign up to copy or download the SVGNo usage limits

Points

Fewer points give smoother, calmer shapes.Irregularity

35%

Fill

Adjust the number of points and how irregular they are, and get a smooth closed SVG path. Randomise until a shape works.

Blobs soften interfaces that would otherwise be all rectangles — behind an illustration, as an avatar mask, or as a decorative shape on an empty state.

How the shape is built

Points are placed at regular angles around a circle, then each radius is jittered by a random amount. The path connects them with quadratic curves through the midpoints, which is what keeps the outline smooth rather than polygonal. Fewer points and less jitter give a calm, near-circular shape; more of either gives something spikier and more chaotic.

Keep them subtle

A blob is decoration, and decoration that draws attention is competing with your content. Low contrast against the background, placed behind the interface rather than beside it, is almost always the right treatment. Loud blobs date a design faster than almost any other trend.

SVG stays sharp everywhere

Because the output is a vector path it renders crisply at every pixel density with no export variants, and it can be recoloured with a single fill attribute — which matters when a dark-mode variant is needed later.

How to use the blob generator

Start with a low point count — six points reads as organic without becoming spiky.
Raise irregularity gradually; past about 50% the shape starts to look chaotic rather than natural.
Pick a fill close to your background colour so the blob sits behind the interface rather than competing.
Randomise to reshuffle until the silhouette works with your layout.
Copy the SVG markup to inline it, or download the file for your design tool.

Use it with

Mesh Gradient Generator — Generate soft multi-point mesh gradients and export them as an image.
SVG to PNG Converter — Rasterise any SVG at 1x, 2x and 3x, with a transparent or solid background.
Border Radius Generator — Shape each corner independently, including nested radii, and copy the CSS.

Frequently asked questions

What is a blob shape used for in UI design?: As a soft background element behind illustrations, an avatar or image mask, or decoration on empty states and onboarding screens. It breaks up layouts that would otherwise be entirely rectangular.
Should I use SVG or PNG for a blob?: SVG. It stays sharp at every pixel density with no export variants, and you can recolour it with a single fill attribute when you need a dark-mode version.
Are the generated blobs free to use commercially?: Yes. The path is generated from your settings — there is no licence, no watermark and no attribution required.