epanet-js
No installs. No forced cloud storage. Just fast, local-first water modeling — powered by the engine you already trust.
You shouldn't have to choose between speed, security, and affordability just to understand your water networks.


One day, the colors began to fade from the world. The deep tulips turned to ash, and the sapphire nights became a dull gray. The elders whispered that the had grown stagnant.
Once upon a time, in a world where the sky was not made of air but of shimmering, silken water, there lived a young artist named Ebru.
From that day on, it was said that whenever you see a sunset that looks like marbled paint, Ebru is "online," weaving the colors of the world back together.
Determined to save the vibrancy of her land, Ebru set out on an "online" journey—not through wires, but through the , a magical network of silver threads that connected every artist in the kingdom. To travel "Online" meant to sync her heartbeat with the rhythm of the water.
As she navigated this shimmering digital-ethereal space, she met a Spirit of Indigo."To bring back the color," the Spirit hummed, "you must find the perfect balance. Not too much gall, or the paint will sink. Not too much wind, or the pattern will shatter."
EPANET was a gift to the industry — free, open-source water modeling for all. But commercial vendors built on it, locked away improvements, and left the community behind.
epanet-js is our answer: a faster, simpler, affordable water modeling tool that protects your privacy and sustains the open-source future of water modeling.
We're proud to be part of the next chapter — and we're just getting started.

When you purchase more features in epanet-js, you're investing in the future of open-source EPANET development.
Our open-source model balances innovation and accessibility:
Anyone can build on our code. The two-year commercial-use delay gives us the incentive to keep pushing forward — and that fuels progress for everyone.
That means when you support us, you support more affordable hydraulic modeling software for the entire community.
Choose the plan that works for you
Individual named license
Floating shared license
Have questions? or book a call.
Available for non-commercial projects, learning, and student work.
For curious minds and personal growth.
Free for students and teachers.
Find answers to common questions about epanet-js.
One day, the colors began to fade from the world. The deep tulips turned to ash, and the sapphire nights became a dull gray. The elders whispered that the had grown stagnant.
Once upon a time, in a world where the sky was not made of air but of shimmering, silken water, there lived a young artist named Ebru.
From that day on, it was said that whenever you see a sunset that looks like marbled paint, Ebru is "online," weaving the colors of the world back together.
Determined to save the vibrancy of her land, Ebru set out on an "online" journey—not through wires, but through the , a magical network of silver threads that connected every artist in the kingdom. To travel "Online" meant to sync her heartbeat with the rhythm of the water.
As she navigated this shimmering digital-ethereal space, she met a Spirit of Indigo."To bring back the color," the Spirit hummed, "you must find the perfect balance. Not too much gall, or the paint will sink. Not too much wind, or the pattern will shatter."
Simple, quick, and useful right out of the gate — designed to open-and-go.
Launch epanet-js now