If you searched for LTspice online, you were almost certainly hoping for a web page that opens LTspice in a browser tab. There is no such thing, and there never has been.
⚡ Need to simulate a SPICE circuit right now in your browser?
While LTspice cannot run in a browser tab, you can open CircuPilot — an independent, free online simulator running real ngspice with zero software installation or signup.
This article explains plainly why LTspice remains desktop-only, what your actual web options are, and what you give up with each — including ours.
LTspice is a desktop program, and only a desktop program
LTspice is free, it is genuinely excellent, and it is distributed by Analog Devices as a download for Windows and macOS. There is no official web build, no cloud version, and no browser port. Analog Devices has never announced one.
The reason is not laziness. LTspice is a native application built around a fast solver and a waveform viewer that expect direct access to the local machine and CPU cores. Nothing about that architecture moves into a browser tab without being rewritten from scratch.
So when a third-party page promises "LTspice online", one of three things is true:
- It is a different simulator using LTspice in the page title for search engine traffic.
- It is a remote desktop streaming a Windows session that happens to have LTspice installed — which works, but is slow, usually paid, and requires an account.
- It is a download link, sometimes not from Analog Devices, which is worth being careful about.
Why people search for it anyway
The pattern behind the query is almost always one of these:
- A locked-down computer. A university lab machine, a work laptop, or a school Chromebook where you cannot install software.
- The wrong operating system. LTspice has no Linux build. Wine works for many people, but it is a project in itself.
- A phone or tablet. There is no mobile LTspice.
- You need an answer in five minutes. A 200 MB install, a schematic drawn from scratch and a
.trandirective is a lot of ceremony to check whether one resistor value is right.
If any of those is you, the honest answer is that you do not want LTspice specifically. You want real SPICE results, in a browser. Those are different requirements, and the second one is achievable.
What actually runs in a browser
| tool | engine | what it is good at | what it does not do |
|---|---|---|---|
| Falstad (Circuit Simulator Applet) | its own solver | instant, visual, superb for teaching current flow | not SPICE, no netlists, no real device models |
| CircuitLab | own engine | polished schematic capture | paid after a trial |
| EveryCircuit | own engine | animated, excellent on mobile | subscription, small library |
| CircuPilot | real ngspice | plain-English input, real netlists, photo of a schematic, Arduino firmware alongside the analog | no PCB layout, no instrument bench, smaller library than LTspice |
The distinction worth understanding is engine, not interface. Falstad and EveryCircuit are fast and pleasant, but they solve with their own approximations — a netlist you write for LTspice will not run in them, and neither will a manufacturer's SPICE model. If you need results you can defend in a report, that matters.
What you actually lose without LTspice
Being straight about this, because a page that claims parity is not worth reading:
- Analog Devices' own model library. LTspice ships with thousands of real parts, and for ADI parts in particular it is the reference implementation. Nothing in a browser matches that.
- Speed on large circuits. LTspice's solver is very fast on switching converters and long transient runs.
- The waveform viewer. Decades of refinement, and still better than anything on the web.
If you are designing a switch-mode power supply, install LTspice. That is what it is for.
What a browser gives you that LTspice does not
- Nothing to install, which is the whole point if your machine is locked down.
- Any operating system, including Linux, ChromeOS and a phone.
- Plain English as an input. In CircuPilot you can type "a 5 V source with a 1 k and 2 k voltage divider" and get an editable schematic — no symbol placement, no wiring.
- A photo of a schematic as an input. Point a camera at a whiteboard or a textbook page and get a circuit you can simulate.
- Firmware and analog in one run. An Arduino sketch compiled and executed against the same circuit SPICE is solving. LTspice does not do microcontrollers at all.
The practical answer
If you can install software and you are doing serious analog design, download LTspice — it is free and it is the right tool.
If you cannot install it, or you are on Linux or a phone, or you want an answer in the next two minutes, use a browser simulator and pick one with a real SPICE engine if the numbers have to be right.
CircuPilot runs actual ngspice in the browser with no signup to try it. Describe the circuit in words, or photograph one, and read the node voltages. It will not replace LTspice for power-supply design, and it does not try to.
Open the CircuPilot simulator →
For a fuller technical side-by-side comparison of solver benchmarks, component libraries, and workflows, see our dedicated guide: LTspice vs Online SPICE Simulators: Which Should You Choose?.
Frequently asked questions
Does LTspice have an official online or browser version?
No. Analog Devices has never released an official web or cloud version of LTspice. LTspice is strictly a native desktop application for Windows and macOS. Any site claiming to offer official LTspice online is either streaming a remote Windows VM, linking to the desktop installer, or offering an independent third-party alternative.
Can you run SPICE simulations in a web browser without installing software?
Yes. Modern web simulators like CircuPilot run actual ngspice directly on high-performance servers, returning real nodal voltages, currents, and waveforms to your browser without downloading or installing any desktop software.
Is CircuPilot an official web version of LTspice?
No. CircuPilot is an independent, browser-based circuit simulator powered by standard open-source ngspice and modern web technologies. It is not affiliated with or endorsed by Analog Devices, but serves as a zero-install alternative for quick SPICE verification, education, and embedded prototyping.
How can I run a SPICE simulation on a Chromebook, Mac, or Linux?
Because LTspice lacks a native Linux build and cannot run on ChromeOS without emulation layers like Wine, web-based simulators like CircuPilot are the simplest solution. They run in any standard web browser tab across ChromeOS, Linux, macOS, Windows, and tablets.
Can an online simulator run my LTspice netlist?
Standard SPICE netlists (.cir) containing basic RLC, diodes, BJTs, MOSFETs, and independent sources transfer easily to ngspice-based tools. However, proprietary encrypted Analog Devices subcircuits (.subckt) or LTspice-specific macro-models only run within native LTspice.