Browser SPICE Guide

LTspice Online: How to Run SPICE in Your Browser (2026)

Updated May 2026 · By the CircuitSim team · 9 min read

LTspice is Analog Devices' free SPICE circuit simulator — fast, accurate, and famously dated. Originally built at Linear Technology in the 1990s to drive adoption of Linear's switching regulator ICs, it has been one of the most widely-used free SPICE tools in the industry for decades. It also still runs only on Windows. The macOS build is materially smaller and less capable; there is no Linux release, no ChromeOS, no iPad, and no official browser version.

That constraint matters more than it used to. Educators setting up an electronics class need a tool that runs on every student's machine without an IT install ticket. Hobbyists want to try a circuit on whatever device is at hand. Professionals want to verify a design in a browser tab rather than chase down a Windows machine. And anyone on a Chromebook, iPad, or managed laptop has no choice at all — LTspice will not run for them.

The closest browser-based alternative is CircuitSim, which we built. The rest of this guide covers what it matches in LTspice, where LTspice still wins, and how to migrate a circuit if you switch.

TL;DR — Quick answer

If you need SPICE in a browser right now: CircuitSim. Free, browser-based, real SPICE engine, schematic editor and netlist editor. Open beta — full launch July/August 2026.
If you can install software and you work on switching regulators or AD/LT-specific ICs: stay with LTspice. Free, deep AD/LT model library, hard to beat for SMPS work.
If you are on a Chromebook or managed device: CircuitSim or another browser-based simulator is the only realistic option. LTspice will not run.

A note on bias

This guide is published on CircuitSim's website, so we have a horse in this race. CircuitSim is the closest browser-based equivalent to LTspice we know of, and yes, we built it. We have done our best to be straightforward about where LTspice is still the better tool, where CircuitSim genuinely matches it, and where neither of them is what you need. We would rather earn your trust than oversell the swap.

Why there is no LTspice in a browser

LTspice has always been a desktop tool. The Windows binary has been hand-tuned over decades by its original author, the simulation kernel is closed source, and porting it to a browser would mean rewriting the engine from scratch. Analog Devices has not done that, and has not announced any plan to.

The articles and forum posts that promise LTspice online are usually one of three things. A remote-desktop service streaming LTspice from a cloud Windows machine — a workaround, not a product, and one that costs the price of a cloud Windows VM each month. A Wine-based Linux trick that runs LTspice inside a Linux container, which works for some circuits, breaks on others, and is blocked on most managed devices. Or a browser-based SPICE simulator that is not LTspice but does many of the same things. Of the three, only the last is a real product category, and it is what most people searching for an online LTspice are actually after.

The closest browser-based alternative to LTspice

CircuitSim Our pick

Yes, this is our tool. Yes, we put it first. With reason: CircuitSim is built specifically to put real SPICE simulation in a browser, with the same analysis types LTspice users already know. It runs in any modern browser. No install, no licence, no Windows required.

What works the same as LTspice:

Industry-standard SPICE engine. The simulation kernel is compiled to WebAssembly and runs locally in your browser. DC operating point, AC small-signal, and transient analysis are the same class of simulation LTspice runs.
SPICE netlist editor. If you write LTspice circuits by hand or paste netlists from a textbook, the same approach works in CircuitSim. Analysis directives (.tran, .ac, .dc) translate directly.
Schematic editor. Drag-and-drop schematic capture sits alongside the netlist editor. Use whichever fits the circuit.
Custom components, including fully dynamic ones. Paste any standard SPICE .model statement, define a .subckt, or build a fully dynamic custom component — behavioural sources, parameterised macromodels, components whose internal state changes during simulation. The same patterns LTspice users already know, with a built-in custom component creator handling the authoring step. If the part you need is not in the prebuilt library, you can build it.
Free. No credit card, no install, no time limit during open beta.

Where CircuitSim is still catching up:

Prebuilt component library is smaller than LTspice's. CircuitSim ships standard SPICE models for common passives, transistors, op-amps, diodes, and basic logic. LTspice ships with the entire Analog Devices and Linear Technology IC catalogue built in — including specific switching regulator parts that LT designed the simulator around. If your simulation depends on a specific AD or LT part, check our library first; if the part is not yet in it, the custom component creator above handles the .model statement when you have it. LTspice handles it with one drag-and-drop.
Some advanced analysis types are not yet shipped. Monte Carlo, noise analysis, and multi-parameter sweep are not in CircuitSim today. If those are core to your workflow, LTspice remains the better tool until that changes.
Open beta. The simulation engine and editor are stable. We are heads-down toward a full launch in July or August 2026.

Best for

Anyone who cannot install LTspice — school laptops, Chromebooks, managed work machines, iPads. Students learning SPICE who want shareable circuits. Educators who want one URL to send a class. Hobbyists and pros doing standard analog and digital work who want fast, friction-free simulation without leaving the browser.

Get started free at circuitsim.com →

Where LTspice is still the right tool

We are not trying to talk you out of LTspice. It is an excellent piece of software with a four-decade pedigree. There are real categories of work where LTspice is the answer and switching to a browser tool would be a step sideways or backwards.

Switching regulator and DC-DC converter simulation

This is the category Linear Technology built LTspice for, and where Analog Devices continues to invest. The LTspice library includes detailed, validated models for hundreds of switching regulator ICs — buck, boost, buck-boost, LDO, and isolated topologies — with parasitics and control-loop behaviour baked in. If you are simulating a power supply that uses an LT8640, an ADA4625, or any other specific AD/LT part, you almost certainly want LTspice.

Long offline simulation runs on large circuits

LTspice is a native binary, and on a fast desktop it can simulate hours of circuit time on a complex schematic without breaking a sweat. Browser-based SPICE runs in the browser tab, which means it competes with your other tabs for memory and shares a single thread by default. For routine work, the difference does not matter. For overnight simulations on a multi-IC design, the desktop wins.

Behavioural sources and advanced .step sweeps

LTspice's behavioural source syntax (BV, BI) and its .step parameter sweeping are mature in ways no browser tool has matched yet. If your workflow leans on these features, you will find the browser tools less expressive today.

Where a browser-based SPICE tool wins

You cannot install software

Locked-down school laptops, Chromebooks, managed work machines, and iPads cannot run LTspice. There is no workaround for most of these. A browser-based simulator is not "second best" here — it is the only option.

You want to share a circuit with one URL

LTspice circuits are .asc files. Sharing one means sending the file, hoping the recipient has LTspice installed on the right OS, and walking them through opening it. A browser-based simulator can produce a link. The recipient clicks; the simulation runs in their browser. For teaching, code review, and forum help, this is a different category of useful.

You are teaching, learning, or both

If you are setting up a Fall 2026 electronics course on a fleet of student-issued laptops, "everyone install LTspice" is a different conversation than "open this URL." Browser tools collapse the setup step. Students who never get past install friction get to the actual circuits.

You are on a Mac

The macOS LTspice build exists but is materially behind the Windows version in features and stability. Many tutorials assume the Windows UI, and Mac users running into edge cases often find their searches do not return matching answers. For Mac users who do not depend on AD-proprietary parts, a browser-based SPICE tool is often a more consistent day-to-day experience.

Comparison: LTspice vs browser SPICE

Capability	LTspice (desktop)	CircuitSim (browser)
Runs in a browser	No	Yes
Windows	Full version	Yes
macOS	Limited	Yes
Linux	Wine only	Yes
ChromeOS / iPad	No	Yes
DC, AC, transient analysis	Yes	Yes
Analog Devices / LT proprietary IC models	Built in, thousands	Custom .model import
Monte Carlo, noise analysis, multi-step sweeps	Yes	In development
Share a circuit by URL	No (file only)	Yes
Install required	Yes	No
Price	Free	Free (open beta)

Migrate an LTspice circuit to CircuitSim in 3 steps

Export the netlist. In LTspice, open the schematic, then go to View → SPICE Netlist. Copy the text.
Paste into the CircuitSim netlist editor. Create a new circuit, switch to the netlist view, and paste. Standard SPICE syntax — voltage sources, R/L/C, MOSFETs, BJTs, .tran, .ac, .dc — works as-is.
Swap proprietary parts. If the netlist references an LT or AD-specific part, replace it with a generic SPICE model or paste the .model statement directly. For now, this is the one manual step.

Frequently asked questions

Is there an online version of LTspice?

No. LTspice is a desktop application from Analog Devices. It runs on Windows (full version) and macOS (limited version). There is no official browser version, no LTspice web app, and no Linux build. If you need SPICE simulation in a browser, you need a different tool — CircuitSim is the closest browser-based equivalent.

Can I run LTspice on a Chromebook?

Not natively. LTspice does not support ChromeOS, and most managed Chromebooks block Linux containers, which rules out workarounds like running LTspice under Wine. The realistic options on a Chromebook are browser-based SPICE simulators such as CircuitSim, or accessing LTspice on a remote Windows machine through a service like Shadow or AWS WorkSpaces.

How accurate is browser-based SPICE compared to LTspice?

For standard analysis types — DC operating point, AC small-signal, transient — a well-built browser SPICE simulator produces results equivalent in accuracy to LTspice. CircuitSim runs the same class of SPICE engine. Where the gap appears is component coverage: LTspice ships with thousands of Analog Devices and Linear Technology proprietary models, particularly for switching regulators and op-amps. If your simulation depends on a specific AD or LT part, LTspice is still the safer choice.

Can I import LTspice .asc or .net files into CircuitSim?

Direct .asc import is on the CircuitSim roadmap but not shipped yet. The current migration path is to copy your SPICE netlist text from LTspice (View → SPICE Netlist) and paste it into CircuitSim's netlist editor. Analysis directives (.tran, .ac, .dc) translate directly. Custom .model statements work as-is, provided the underlying physics is standard SPICE.

Is CircuitSim free like LTspice?

Yes. CircuitSim is free during open beta — no credit card, no install, no time limit. We plan a full launch in July or August 2026 with paid tiers for organisations and educators. A free individual tier will continue after launch.

Does LTspice work on a Mac?

Analog Devices ships a macOS build of LTspice, but it is materially behind the Windows version in features and performance. Several common LTspice tutorials assume the Windows UI. For Mac users who do not need AD-proprietary models, a browser-based SPICE tool often produces a more consistent experience.

When should I keep using LTspice instead of switching?

Keep LTspice if your work depends on Analog Devices or Linear Technology proprietary models, especially switching-regulator IC simulation; if you need long offline simulation runs on large circuits; or if you rely on LTspice-specific features like behavioural sources and parametric .step sweeps in ways no browser tool has matched yet. For most coursework, intermediate analog, and circuits you want to share or embed, a browser SPICE simulator is the better day-to-day tool.

Is browser-based SPICE stable enough for serious work?

The CircuitSim core simulation engine — DC, AC, and transient analysis — works reliably today and is what users build on. Some advanced LTspice features (Monte Carlo, noise analysis, multi-parameter sweep, S-parameter export) are not yet in the browser version. For introductory through intermediate work and for any circuit you want to share with a teammate or student in one click, the browser tool wins. For specialty validation work, run it in LTspice.

Start simulating free at circuitsim.com →

LTspice is a trademark of Analog Devices, Inc. Linear Technology is a trademark of Analog Devices, Inc. CircuitSim is not affiliated with Analog Devices. All other marks belong to their respective owners.