Every design here is shared under CC BY-SA 4.0 — open one, build on it, and share yours back.
Volta is a live analog and digital circuit simulator that runs entirely in your browser. Draw a schematic, press Run, and the circuit comes alive: current flows as moving dots along the wires, wires take colour from their node voltage, capacitors show which way they are charged, LEDs light, motors spin up against their own back-EMF, and a built-in oscilloscope traces any node you point at.
It is not a picture of a circuit. Underneath is a real solver — modified nodal analysis with Newton–Raphson for the non-linear parts — the same method the industry-standard tools use. You can open the Math panel and read the equations it built, the matrix it assembled, and how the iteration converged.
Around fifty parts: sources, passives, diodes and transistors, op-amps, relays and motors, logic gates, latches and flip-flops, a counter, a 7-segment display, a 555 timer, converters, and voltmeters, ammeters, ohmmeters and wattmeters that read live on the schematic.
Transient simulation, AC sweeps with Bode plots, an oscilloscope, and a math view that shows the solver's own working so the result is something you can check rather than something you must trust.
Write an Arduino-style sketch and run it against the live schematic in simulated time — pinMode, digitalWrite, digitalRead, delay — and watch the hardware respond.
Describe a circuit and have it built for you, or ask why the one on screen is not behaving. The assistant reads the schematic you are looking at.
An installable web app that runs entirely in the browser. It works on a laptop, a phone, or a school machine with a slow connection, and it keeps working when the connection goes away entirely, so a lesson does not depend on the network holding up.
Members publish designs under CC BY-SA 4.0 so anyone can open them, change them and share them back — with credit following the work automatically.
public/about-photo.webp
Developed by
Software / ML Engineer
I have spent the last six years building software. Somewhere in the middle of a computer engineering course at university I met the other side of it — the side where the abstractions stop and something physical is actually happening — and I have been quietly fascinated by electronics design ever since. Volta is what happens when those two interests stop taking turns.
The tools I learned on would tell you the answer without ever showing you the circuit thinking. I wanted one that does the opposite: current you can watch moving, wires that take their colour from their voltage, and a Math panel that will show you the matrix it just solved if you ask it to. It runs in the browser on whatever device a student already owns, and keeps working when the connection does not.
The commons is the other half of the idea. Circuits are far easier to learn from when you can open somebody else's, take it apart, and put it back together differently — which is roughly how I learned to write software, and there is no reason electronics should be lonelier than that.
Publish your designs, and build on everyone else's. The editor works fully without an account.
Volta is a circuit simulator that runs in your browser. The editor needs no account, sends nothing anywhere, and keeps working offline. Everything in these terms concerns the commons — the optional part where members publish designs for others to open and build on.
You must be at least 15 years old to create an account. If the law where you live sets a higher age at which you can agree to this yourself, that age applies to you instead. Under 15, the editor remains free to use in full; only the commons is closed to you.
Keep your password to yourself. Tell us if you think someone else has it. You are responsible for what is published from your account.
You keep the copyright in your designs. By publishing one to the commons you licence it to everyone under Creative Commons Attribution-ShareAlike 4.0: anyone may use it, change it and republish it, provided they credit you and share their version on the same terms.
That licence cannot be withdrawn. You may delete a design, and it will leave the commons — but copies others have already made, and work they have already built on it, remain theirs to keep and to share. This is what makes a commons a commons, and it is why the licence is shown and agreed to at the moment of publishing rather than buried here.
Anything unlawful; anything that harasses, bullies or endangers another person; anyone else's work presented as your own; personal information about someone who has not agreed to it; or anything that exists to interfere with the service or with other members.
Signed-in members can ask the assistant to build or explain a circuit. It is answered by a language model, which means its output is not checked by anyone — it can produce a circuit that looks right and is not. Treat what it gives you as a draft to simulate and inspect, on the same terms as clause 8: it is not a substitute for your judgement.
Because each request costs us money, the assistant is rationed to a fixed number of requests per member per day, and we may change that number, or withdraw the assistant, without notice. Use it for circuits. Using it as a general-purpose language model, or trying to get round the limit, is grounds for losing access to it.
Every published design carries a Report button. A moderator can remove a design from the commons. We may suspend or remove an account that repeatedly breaks these terms.
You can delete your account at any time from the account panel. That removes your login, your profile and every design you have published. It is immediate and cannot be undone.
Volta is a teaching and design tool, not a certified engineering instrument. Its results are as good as its models and its author can make them, and they are not a substitute for your own judgement. Do not rely on it for anything where a wrong answer is dangerous or expensive. It is provided as it is, without warranty of any kind.
If these terms change materially, the version number changes and you will be asked to accept the new ones before publishing again.
The editor collects nothing. If you join the commons, we hold the least we can get away with: an email address so you can sign in, a display name and a handle so your work can be credited, and optionally a country and a school. Nothing is sold, and nothing is shared with advertisers, because there are none.
Nothing leaves your device. Your circuits, your preferences and your Anthropic API key if you set one are stored in your own browser and are never sent to us. There is no analytics and there are no tracking cookies. The one exception is the circuit assistant, which has to send your question somewhere to answer it — see below.
Asking the assistant a question sends your question and the circuit currently on the canvas away to be answered. Nothing else goes with it: not your email, not your handle, not your other designs. It happens only when you press Ask, never in the background.
There are two routes, and which one you are on decides who sees it:
| Route | Where your question goes | What we keep |
|---|---|---|
| Signed in — the assistant works with no key of your own | To our server, and on to Anthropic, whose model writes the answer. We do not store the question or the circuit. | A count of how many times you asked, per day, so one member cannot exhaust the service for everyone. A number and a date, not your words. |
| Your own API key — offline, self-hosted, or signed out | Straight from your browser to Anthropic. It never touches our server, and we never see it. | Nothing. We are not part of it. |
Anthropic processes the request in order to answer it, under their own terms. If you would rather nothing left your machine at all, do not use the assistant — every other part of the editor works without it.
| What | Why | Shown publicly |
|---|---|---|
| Email address | To sign you in and let you reset a password | No |
| Handle and display name | To credit your published designs | Yes |
| Country | Optional. To show the commons is worldwide | Yes, if given |
| School | Optional, and off by default | Only if you switch it on |
| That you confirmed your age and accepted these terms | To show we asked | No |
| Designs you publish | They are the point of the commons | Yes |
| How many times you used the assistant today | To stop one member exhausting it for everyone. A count, never the questions | No |
Asked once, when you create an account, to work out whether you are old enough. It is used and thrown away. We do not store it, because storing it would mean holding a stronger identifier than anything else here in order to answer a question we already have the answer to.
Off unless you switch it on, and the rule is applied by the database rather than by the page — a design cannot show a school its author did not choose to show, whatever any part of the app asks for. Your name next to your school and your town is the combination that says where to find you, which is why this one is opt-in.
Until you delete your account, which you can do yourself at any time from the account panel. That removes your login, your profile and every design you have published, immediately. Designs others have already copied or built on remain theirs, under the licence you published them with.
You can see everything we hold about you in the account panel and in My designs. You can correct it there, and you can delete all of it there. If you would rather ask a person, or you want a copy of your data in a portable form, get in touch.
Accounts and published designs are stored with Supabase, our database provider, in the region chosen when the project was set up. Email for sign-up confirmation and password resets is sent through our email provider. Questions you put to the circuit assistant are answered by Anthropic. None of the three uses your data for anything but providing that service to us.
The commons is for members of 15 and over. If you believe a younger member has an account, tell us and we will remove it.
[Contact address to be filled in before publishing. A privacy notice without a way to reach a human is not one.]
Sign in to share your designs with the commons and build on other members' work. Everything in the editor keeps working without an account.
Choose a new password for .
Signed in as . This is how you appear on anything you share.
Leave this off if you'd rather not say where you are. Your name and school together identify where to find you, so it stays hidden unless you turn it on.
Leaving deletes your account, your profile and every design you have shared. It cannot be undone, and anything others have already built on stays theirs — that is what the licence means.
Runs against the live circuit in simulated time. Place MCU pin parts on the schematic and address them by number. Supported: setup loop pinMode digitalWrite digitalRead delay millis, plus int/float, if, while and for.
Your circuit's connectivity, in the format Pcbnew imports. It is not a board: Volta knows what is joined to what, not what package anything comes in. Read what it could not carry across before laying anything out.
Sign in to use the assistant — approved members get it with no key and nothing to set up. Close this and use Sign in in the toolbar.
Running Volta offline or self-hosted, with no account? Paste your own Anthropic API key instead. It is stored in this browser's local storage and sent only to api.anthropic.com — which means any script running on this page could read it. Use a key you're comfortable with that, and revoke it if you share this device.