Trusted by teams across the water industry
epanet-js
From GIS data to a running model in minutes — then calibrate, plan, and operate your water network with confidence. Powered by the EPANET engine you trust, modernised for the way you work today.
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Trusted by teams across the water industry
Hydraulic modeling is typically fragmented across separate tools: desktop GIS for asset cleanup, spreadsheets for demand balancing, and legacy desktop software for simulation runs. Every handoff between them burns engineering hours and risks data drift.
epanet-js consolidates the pipeline into a single environment. Build your network geometry, allocate customer meters, target field loggers, calibrate against observed data, evaluate operational shutdowns, and sequence multi-year capital plans—all on a single, continuous model without file conversions or spreadsheet workarounds.
Import Shapefile, GeoJSON, CAD, or legacy .inp files directly without manual file prep. Automated snapping, multi-source terrain elevation sampling, and the pre-simulation Network Review resolve topological errors upfront—turning weeks of cleanup into a same-day deliverable.
epanet-js breaks the network into zones, searches many parameter combinations, and proposes the most likely fit, then documents every option so you can accept, adjust, or reject it.
Calibration assistant
Suggestion 2 of 7
Zone B · 14 pipes
Run available, needed, and designed fire flow across every hydrant, or generate instant pressure-flow curves for any junction. Thousands of simulations in your browser turn multi-day development capacity reviews into immediate answers.
Fire flow analysis
| Junction | Available (l/s) | Status |
|---|---|---|
| J107 | 47.2 | Pass |
| J67 | 30.9 | Fail |
| J288 | 27.3 | Pass |
Model main isolations, PRV set point changes, and rezoning schemes against a verified baseline. Observe system-wide dynamic pressure responses, evaluate customer outage footprints with pressure-dependent demands, and maintain a reproducible record of every decision.
Explore the tools that support your network from layout to daily operations.
Go from GIS layers and field measurements to a calibrated baseline model.
Bring in an existing model or continue from the one you built, and run the analyses that planning and operations depend on.
Bring in an existing model from any platform
Plan your network and investment years ahead
See how your network responds before you make a change
Track water age, source, and chlorine across the network
Find available flow and capacity across your network
Find the valves that isolate each part of the network
Launch epanet-js free in your browser, or book a demo to see how it fits your workflow.
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An intuitive, modern interface that gets you to answers quickly — local-first and secure, all on top of the trusted EPANET engine.
epanet-js operates local-first. Your networks, customer data, and simulation results process and save directly on your machine. No model data or GIS layers are uploaded to external servers, allowing you to work completely offline with full control over proprietary network information.
Cloud workspaces are strictly opt-in for team collaboration.
epanet-js replaces the rigid constraints of legacy desktop modeling with an intuitive, spatial workspace:
Utilities
Eliminate single-seat bottlenecks. Give operators and planners direct access to test shutdowns, evaluate connections, and check pressures without waiting on a specialized license.
Consulting engineers
Scale modeling capacity without expensive software subscriptions. Iterate faster on master plans and calibrations, then deliver working models in any format.
Educators & students
Teach distribution hydraulics without license servers or legacy software quirks. Students can build networks and observe dynamic system behavior in minutes on any laptop.
Whether you manage complex transmission and distribution networks, deliver master plans as a consultant, teach hydraulic engineering, or design community supplies in remote settings, epanet-js adapts to your workflow.
Used across the water industry, from utilities to universities
Open an existing model on our free tier with zero installation, or schedule a technical walk-through tailored to your team's workflow.
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Hydraulic models contain sensitive spatial geometry, asset vulnerabilities, and operational controls. epanet-js is engineered local-first: your network files are parsed, simulated, and saved entirely within your browser on your local device.
Nothing touches external servers by default. For organizations requiring shared team collaboration, we offer strict regional data residency and fully air-gapped, on-premises deployments.
Models run and save directly on your machine. Nothing is uploaded unless you choose to.
Data-residency options and a self-hosted, on-premise deployment for teams that need complete ownership.
All traffic is served over HTTPS/TLS, so anything that does move is encrypted end to end.
Source is public from day one, becoming fully open after two years, so our security can be reviewed.
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.
Launch it free and import your data right now, or book a demo to walk through it with us.
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Start free, no account needed. Upgrade when your work needs more.
Try Pro free for 14 days. No card needed, just a work email. The trial starts in the app, the first time you use a Pro feature.
Includes
Everything in Free, and:
Everything in Pro, and:
Advanced workflows:
Everything in Ultimate, and:
Have questions? Send us an email or book a call.
Everything that's included in each plan.
| Feature | ||||
|---|---|---|---|---|
| Platform | ||||
| Local-first — data stays on your machine | ||||
| No limits on model size | ||||
| Simulation engine | ||||
| EPANET Toolkit 2.3.5 engine | ||||
| Network editing | ||||
| Zone polygons – import and visualize | ||||
| Element properties | ||||
| Demand management | ||||
| Data libraries | ||||
| Assign roughness by material and age | ||||
| Data exchange | ||||
| Third-party model import and export | 1 model | Unlimited | Unlimited | |
| Model building | ||||
| GIS model import — Pro builder | ||||
| Results & visualization | ||||
| Map & layers | ||||
| Custom vector file layers (GeoJSON, Shapefile) | ||||
| Network review | ||||
| Missing or invalid attribute checks | ||||
| Advanced analysis & operations | ||||
| Scenario management | ||||
| Create and switch scenarios | ||||
| Compare simulation results between scenarios | ||||
| Reporting & exports | ||||
| Advanced workflows | ||||
| Cloud & collaboration | ||||
| Multiple team members | ||||
| AI | ||||
| AI-assisted modeling | ||||
| Support & licensing | ||||
| Priority support | ||||
| Pay by invoice | On request | |||
| Seats | 1 | 3 | Custom | |
| Self-service seat management | ||||
| Security & deployment | ||||
| Single sign-on (SSO) | ||||
| On-premises deployment | ||||
Find answers to common questions about epanet-js.
You may not know this, but for decades, the U.S. EPA has given the water industry an extraordinary gift: the free and open-source hydraulic modeling software EPANET. Odds are, if you've used any commercial hydraulic modeling software today, it was built on the EPANET engine.
The problem is, instead of giving back to their open-source roots like other industries do, big-name software vendors took EPANET's open code, built private tools on top of the engine, and then locked those improvements behind patents and proprietary licenses.
Some vendors even pressured the EPA to focus only on the engine — discouraging any effort to improve the interface or user experience for everyone else.
Those vendors now charge you exorbitant prices to use their software while EPANET lags behind — and utilities, engineers, and educators with smaller budgets suffer.
We think this is backwards — and we're on a mission to change it. We're focused on creating a better experience for the entire hydraulic modeling community.
That's why we built epanet-js under an FSL license — because we want to give you an affordable, easy-to-use water modeling option that creates a sustainable future for open-source EPANET development.
Support EPANET by using software that supports it back.
Simple, quick, and useful right out of the gate — designed to open-and-go.
Launch epanet-js now
