Circle Packing

Grow until collision, keep what fits.

images.circles · v1 · renderer canvas

26,000 darts · 3–95 px · Mixed fill and outline · 2.5 px gap · coloured by a noise field

Each candidate grows until it meets a circle already placed, the canvas having no say — the circles are allowed to run off the edge, so the picture reads as a crop of something larger rather than as a diagram fitted to its frame. Candidates that cannot reach the minimum radius are discarded, which is most of the later ones.

[data-canvas-stage] { display: none; }

Drawn in the browser

This generator does not send you an image. The server sends a short description of one — the parameters below, plus a 32-byte key — and the drawing is done here, from the same byte stream the server would have used. That needs JavaScript, so with it switched off there is nothing to show.

The description itself is still public: /api/v1/g/images.circles returns it, and the maths is in resources/js.

26,000 darts · 3–95 px · Mixed fill and outline · 2.5 px gap · coloured by a noise field

Controls · from schema()

Width

256 2048

Height

256 2048

Darts thrown

500 90000

Candidate points tried. Most of the late ones land inside a circle that already exists and are thrown away; the ones that survive are what fills the gaps.

Smallest circle

1 40

Candidates that cannot grow this large are discarded. Raise it and the gaps between the big circles stay open.

Largest circle

8 320

Gap

0 24

Clear space kept between circles. At zero they touch exactly, which is the true packing and reads as denser than it is.

Draw as

Stroke weight

0.03 0.5

As a fraction of each circle's own radius, so a large circle is drawn more boldly than a small one rather than the same.

Colour by

Ground

Colour

Palette size

2 12

Grain

0 0.08

Entropy source

Picking a source changes the story on the receipt, never the quality: anything below class A is mixed with the OS CSPRNG before it reaches you. This result actually came from NOAA Space Weather.

seed token PHPT5TKS4532SWXNZ9CEHJZ464

Re-render keeps this token. Generate replaces it. That is the whole idea.

Burned into the corner before the file is written, so the image keeps its provenance wherever it ends up:

entropy in

16 bytes

stream used

36 bytes

rejections

duration

140 µs

palette

background

#010103

attempts

26,000

radius range

3.0–95.0 px

hexagonal limit

90.69% (equal circles, densest possible)

Seed receipt

Class C · Observational

Planetary K-index 1.00 — the geomagnetic field was quiet when this was made.

Carries only tens of bits of genuine surprise. Always mixed with the OS CSPRNG.

source: NOAA Space Weather
observed: 2026-10-30T11:13:00+00:00
latency: 296ms
mixed with: csprng — always

https://www.swpc.noaa.gov/products/planetary-k-index ↗

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The token is the seed, so this link recomputes the result rather than looking it up. No database, and it works for as long as v1 does.

This page and /api/v1/g/images.circles run the same code. There is no private endpoint.

Circle Packing

Result

Measurements

Seed receipt

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