Alternative
The Best LTspice Alternative
LTspice is a fast, free, industry-trusted SPICE circuit simulator — unbeatable for analog circuit design on the desktop. But it's Windows/desktop-first and covers only electronics. PolySim runs in any browser and spans circuits plus physics, math, controls, DSP, and more.
Why teams switch from LTspice
- Desktop-only
- Electronics-only
- No browser/sharing
What you get with PolySim OS
| Feature | PolySim OS | LTspice |
|---|---|---|
| Price | Free locally | Free |
| Runs in browser | Yes | No — desktop app |
| Scope | Circuits + physics/math/DSP/controls | Analog/mixed circuits only |
| Shareable links & embeds | Yes | No |
| Interactive sliders | Yes | Parameter sweeps |
See PolySim in action
Choose LTspice for serious analog circuit design; choose PolySim for browser-based, multi-domain simulation and teaching that includes circuits.
Ready to leave LTspice?
Chemistry Reaction Kit — $19
Reaction kinetics, equilibrium, and transport simulations.