Pick a scene
Choose the dusk murmuration, the fish school, neon streaks, pastel kites or fireflies.
Flocking Simulator
Starlings at dusk, a school of fish, glowing fireflies: watch simple rules turn into mesmerising swirls. Touch to scare or lead them, draw walls, and save a picture or a calming video clip.
Open Flocking Simulator →How to use the flocking simulator
Play with the flock
Touch to scare the boids like a hawk, switch to the lure to lead them, or draw walls for them to flow around.
Tune and save
Adjust separation, alignment, cohesion, speed and wind, then save a PNG or make a video clip.
Tips for mesmerising flocks
More alignment, tighter streams
Raise alignment for long ribbons that turn together; lower it for a buzzing swarm.
Let the hawk work
With the predator on, the murmuration splits, folds and joins again like real starlings.
Lead with the lure
Switch to the lure and move your finger slowly: the fish follow and circle around it.
Draw a reef
Draw walls across the middle and watch the school part and flow around them.
Calm screen
Choose the calm pace, turn on trails and go full screen for a relaxing ambient screen.
Same seed, same flight
The video is replayed from the seed, so a shared link gives the same clip on any device.
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Flocking simulator FAQ
What are boids?
Boids are simulated birds that follow three simple rules: keep some distance from neighbours (separation), fly the way they fly (alignment) and stay close to the group (cohesion). Together these rules create realistic flocks, schools and swarms. The model was introduced by Craig Reynolds in 1987.
Is this flocking simulator free?
Yes. It is free with no sign-up and no watermark, and it runs right in your browser.
How many birds can it show?
Up to 3,000 boids at once. A fast spatial grid finds each boid’s neighbours, so even big murmurations stay smooth.
How do I interact with the flock?
With the hawk tool, touch or move the mouse to scare them away. With the lure, they follow your finger. With the pen, draw walls they avoid, and erase walls with the eraser.
What do the sliders do?
Separation sets personal space, alignment how strongly boids copy their neighbours’ heading, cohesion how strongly they gather, vision how far they look, speed how fast they fly and fear how strongly they flee. Wind pushes the whole flock.
Can I make a video?
Yes. Choose 9:16, 1:1 or 16:9, a length and frame rate, and the simulator replays your scene from its seed, with your walls and settings, into an MP4 (or WebM).
Can I use it as a screensaver?
Yes. Press full screen, choose the calm pace and the controls fade away. The screen stays awake while it plays.
Does it work on phones?
Yes. It is made for touch: tap to scare, drag to lead, pinch-free big buttons, and the settings slide up from the bottom.
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