Explaining a circuit in words is slow. "The LED goes to pin 9 through a 220 Ω resistor and the other side to ground" takes a paragraph and still leaves room for a wrong guess. A link that opens the working circuit — press Run and see it — settles the question in one click, whether you are asking a forum for help, handing in homework, or showing a classmate why their 555 does not oscillate.
⚡ Try one now
These two links open real circuits. Press Run:
• Arduino Uno blinking an LED — schematic and sketch together
• 555 timer flashing an LED at 1 Hz — with an oscilloscope on the output
No sign-up, nothing to install.
What a good share link needs
A shared simulation is only useful if the other person can do something with it immediately. That comes down to four things:
1. It opens without an account. Every sign-up screen loses people — especially on a phone, and especially a teacher marking thirty submissions.
2. It runs, not just displays. A picture of a schematic is not a simulation. The point is to press Run and see the LED, the meter or the waveform.
3. The code travels with it. For an Arduino circuit, the sketch is half the circuit. A link that drops it shares the wiring and loses the behaviour.
4. The recipient can edit without breaking yours. They should be able to try a fix and send back their own version.
How the common simulators share
This is the state of things at the time of writing (September 2026); check each tool's own help if it matters to you.
| Tool | How you share | Account needed | Arduino code included |
|---|---|---|---|
| Falstad circuit simulator | Export the circuit as a link; the whole circuit is encoded in a long URL | No | No — no microcontroller support |
| Tinkercad Circuits | Invite people or make the design public from your Autodesk account | Yes to create; usually to copy or edit | Yes |
| Wokwi | Save the project and share its URL | Yes to save | Yes — microcontroller-focused, not SPICE analog |
| LTspice / desktop SPICE | Send the .asc file | Recipient installs the program | No |
| CircuPilot | Press Share, copy the link | No, on either side | Yes |
Falstad is excellent for quick analog intuition and needs nothing at all, but it has no Arduino and its links get very long. Tinkercad and Wokwi handle microcontrollers well and tie projects to an account. Desktop SPICE is the most precise and the least shareable: the other person has to install it first. If you are weighing desktop against browser tools more generally, LTspice vs online SPICE simulation goes through the trade-off.
Sharing a circuit on CircuPilot, step by step
1. Get the circuit on the canvas. Type it ("an Arduino reading a potentiometer on A0 and dimming an LED"), photograph it from a book, sketch it by hand, or place parts from the sidebar.
2. Press Share in the top bar. A link like app.circupilot.com/c/wrqb--yX appears.
3. Copy it, or send it straight to WhatsApp, Telegram or X. On a phone, the Share… button opens your phone's own share sheet.
4. The other person opens it and presses Run. They see the same schematic, the same Arduino code, and the same result you did.
5. Find your links again later under Your shared circuits in the same window, with how many times each was opened. Delete any you no longer want public.
Pressing Share twice on an unchanged circuit gives the same link rather than a new copy, so you can press it freely.
When a link beats a screenshot
- Asking for help. "My LED doesn't light" plus a link lets the person answering press Run and see the problem instead of guessing from a photo. If you are the one answering, build the fix and reply with its link.
- Homework and lab reports. A link to the working circuit next to the calculation shows it actually behaves as claimed. For the usual first circuit, what resistor do I need for an LED walks through the numbers.
- Teaching. Put a link on a slide; students open it on their phones and change a value themselves. The 555 timer calculator and the other free calculators open their result as a circuit you can share the same way.
- Before you build. Send the circuit to a friend to check the wiring before anything goes on a breadboard.
A note on privacy
A share link is unlisted, not secret: anyone who has the link can open the circuit, and nobody can find it without the link. Do not put anything in a circuit title you would not want a stranger to read, and delete links you no longer need.
Frequently asked questions
Does the other person need an account to open a shared circuit?
Not on CircuPilot — the link opens the circuit in the browser and it runs straight away. On some other tools the recipient can view without an account but has to sign in to copy or edit the design.
Is the Arduino code included in the link?
Yes. The link carries the schematic and the sketch together, so whoever opens it sees your code in the editor and the same blink, PWM or LCD output you saw.
Can I change a circuit someone shared with me?
Yes. Edit it freely — your changes do not touch the original link. Press Share again to get a link to your version.
How do I delete a link I shared?
Open Share and find it under Your shared circuits, then press the ✕ next to it. Anyone who opens that link afterwards gets a not-found message.
Can I share a circuit as a file instead?
Yes — Save downloads a JSON file with the circuit and its Arduino code, and Load opens it again. A link is simpler when the other person is on a phone or does not want to download anything.