Source: https://mokxi.com/learn/free-circuit-simulator-for-high-school Updated: 2026-09-28 Learn # A free circuit simulator for high school physics, engineering and CTE Written by the Mokxi team, updated September 28, 2026 Try it now, no account Sign up free or see every lesson - 192 parts on the bench - 25 boards running now - 1.00x real time, on every board Click to open it in the editor Three resistors from 5 V to ground with a multimeter on the taps. Open it to move the probes. Mokxi is a free circuit simulator for high school classes that runs in the browser, Chromebooks included, with breadboards, meters and a scope. A high school circuits unit needs three things a textbook cannot give: a circuit students can change, a meter they can read, and enough of both for every student at once. The circuit above is the first one most physics classes measure: three resistors in a line from 5 volts to ground, with a multimeter on the taps. It is running in this browser tab, and every reading on it comes out of a real circuit solver. Mokxi is free to use, runs in a browser on the Chromebooks most US schools already have, and opens without a student account. This page is for the teacher deciding whether it fits a physics, engineering, or career and technical education (CTE) course, and it tries to be straight about where it does not. ## Where it fits in the courses you teach Physics. The DC circuits content of a high school physics course, and of AP Physics 2 and AP Physics C: Electricity and Magnetism, is Ohm’s law, series and parallel resistors, Kirchhoff’s laws, power, and capacitors charging and discharging through a resistor. Every one of those can be built, measured and changed here: a bench supply, resistors, capacitors, a multimeter that reads volts, amps and ohms, and a two-channel oscilloscope that draws an RC curve you can read the time constant off. Engineering and CTE. Digital electronics courses move from logic gates to flip-flops, counters and the 555 timer, and Mokxi has the 74HC chips as real 14-pin packages on a breadboard, with supply pins that have to be wired. Courses that reach microcontrollers can go on to an Arduino Uno, an ESP32 or a Raspberry Pi Pico in the same editor, with real C++ compiled in the browser. Middle school and intro courses. The same breadboard and the same parts work for a first circuit: an LED, a resistor and a button, with the answer to why an LED needs a resistor one meter reading away. ## Standards, honestly Mokxi has not been reviewed or certified against any standard, and this page will not claim an alignment it does not have. What can be said is where the activities naturally sit. NGSS engineering practices ask students to design, test and refine a solution, and HS-PS3-3 asks them to design, build and refine a device that converts one form of energy into another; a simulator is a good place to design and test before building, not a replacement for the build. For computer science, CSTA standard 2-CS-02 asks middle school students to design projects that combine hardware and software to collect and exchange data. An Arduino project with a sensor and a display is that, whether it runs on a desk or in the simulator. If your state or district uses its own framework, the curriculum page maps week-by-week activities you can check against it yourself. ## Running a class with it Students need nothing but a browser. The simulation runs on each student’s own machine, so thirty students at once is thirty Chromebooks working and nothing queued on a server. A student can open the editor and run a circuit without an account; saving work and joining a class need one, with Google, GitHub or an email address. Classes add what a teacher needs to run a unit: a roster, starter projects handed out to everyone, checks that grade a circuit automatically (a node voltage in range, an LED lit), submissions you can open and run yourself, and a class wall. Every board and part is on the free plan. The class tools come with Pro and the Teacher plan, and the free 30-day trial, started from the class page, covers one class of up to forty students with every tool, once per teacher account, with no card, which is enough to try a unit with a real class first. School IT usually asks two things, and both have a page: the domains to allow through a web filter, and how student data is handled. ## Where another tool is the better choice For younger students who need block coding, Tinkercad Circuits is the better first tool; Mokxi is text C++ only. For a college-level course built around SPICE analysis, Mokxi runs SPICE decks on an engine checked against ngspice, and LTspice or ngspice still go further, with manufacturers’ model libraries, distortion and Monte Carlo analysis. The comparison pages spell both out, with where the other tool leads listed first. And no simulator replaces a real bench. Students should still hold a resistor, read its bands and burn out one LED. The case for a simulator is that they arrive at the bench knowing what the circuit should do. ## Three labs to start with Ohm’s law and the divider. Open the circuit above, predict each tap voltage with V = IR, then check with the meter. Change one resistor and predict again. The RC time constant. A square wave into 10 k and 100 nF, on the scope. Students measure the time to reach 63 percent and compare it with R times C, which is 1 millisecond. Series and parallel LEDs. Three circuits side by side show why two LEDs in parallel should not share one resistor, with a current reading that explains it. ## Questions Is there a free circuit simulator for high school students? Yes. Mokxi is free to use in a browser, with every board and every part on the free plan, and students can open and run circuits without an account. Does it work on Chromebooks? Yes. It runs in Chrome with nothing to install, and the simulation runs on the Chromebook itself. Is Mokxi aligned to NGSS or AP Physics? It has not been reviewed or certified against either. Its circuits cover the DC circuit and RC content those courses teach, and this page says where its activities fit so you can judge for yourself. Is it a good Tinkercad Circuits alternative for schools? For classes that want real C++, an ESP32 or a Pico, real 74HC chips, or bench instruments, yes. For younger students who need block coding, Tinkercad is still the better start. Related ## Keep going Ohm's Law, in a Circuit You Can Run Series vs Parallel Circuits, Seen With LEDs The RC Time Constant, on an Oscilloscope How to Use a Multimeter: Practice on a Virtual One Mokxi for teachers The week-by-week curriculum Mokxi and Tinkercad Circuits for schools, compared School IT setup The project page, with the full sketch Sources ## Where the facts on this page come from - College Board: AP Physics 2 course page (checked 2026-09-27) - NGSS: HS-PS3-3 Energy - CSTA K-12 Computer Science Standards ## Build this for real Open the editor, change a value and watch the number move with it. Nothing to install, and no account needed. Start building Open the editor