Fireflies

A beautiful interactive toy about how fireflies flash in sync.

Open in a new tab

Open-source project "Fireflies" by Nicky Case, used under the CC0 (public domain) license. Source code

Runs in your browser. Nothing you enter is sent or stored.

How to use Fireflies

  1. Watch the fireflies and read along.
  2. Click to add fireflies and tweak how they react to each other.
  3. See order emerge from simple rules.

Frequently asked questions

Who made it?

Nicky Case, released into the public domain (CC0).

Is there sound?

Yes, gentle night ambience. Use your device volume to adjust it.

Is Fireflies free?

Yes. Fireflies is free to use with no sign-up and no watermark.

Is my information saved or sent anywhere?

No. Everything is calculated in your browser. Nothing you enter is sent to a server or stored.

Does it work on my phone?

Yes. It works in any modern browser on Windows, Mac, Linux, Android and iPhone. Very large files may be slow on older phones.

More Fun tools

View all
Spin the WheelA random decision wheel. Random Name Picker & Team GeneratorDraw names or make random teams. Dice RollerRoll D6, D20 and more. Coin FlipHeads or tails, with stats. Random Number GeneratorRandom numbers in any range. Age Calculator & Birthday CountdownExact age and birthday countdown.