Circuit Diagram Maker
Describe a circuit in plain English, or upload a photo of a sketch, and AI draws a clean schematic with standard symbols, a checked netlist and a parts list, ready to export as an image or a KiCad project.
- Standard IEEE and IEC symbols
- Checked netlist, not an AI picture
- SVG, PNG, PDF, KiCad and SPICE
- Free to start
Quality
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AI drafts can be wrong. Check values, ratings and safety before you build.
The capacitor shorts high frequencies to ground while low frequencies pass. Above the cutoff the output falls by 20 dB per decade.
Circuit diagram examples
Twelve hand-checked circuits drawn by the same engine. Open one in the maker to change it, restyle it or export it for free, or read how it works, with its formulas and parts list.
Inverting op-amp amplifier
A gain of −10 from a 1 kΩ input and a 10 kΩ feedback resistor.
- op-amp
- amplifier
- analog
NPN relay driver
A GPIO pin switches a 5 V relay through a 470 Ω resistor and a 2N2222, with a flyback diode.
- transistor
- relay
- arduino
NPN common-emitter amplifier
A 2N3904 with divider bias, an emitter bypass and coupling capacitors.
- transistor
- amplifier
- analog
Bridge rectifier 5 V power supply
12 V AC to a regulated 5 V with a DB107 bridge, a filter capacitor and a 7805.
- power supply
- rectifier
- regulator
Sallen-Key low-pass filter
A second-order, unity-gain active filter with a cutoff near 1.07 kHz.
- filter
- op-amp
- analog
Arduino potentiometer LED dimmer
An Arduino Uno reads a pot on A0 and dims an LED with PWM on D9.
- arduino
- microcontroller
- led
Last updated
How do I make a circuit diagram online?
Type what the circuit is and which parts it uses into the maker above, for example “a 9 V battery, a switch, a 330 Ω resistor and a red LED in series”, and press Generate. The AI writes the circuit as a list of parts and connections, and ProtoFlow’s layout engine draws it with standard symbols. Check the drawing and the netlist, change any value for free, then download SVG, PNG or PDF, or a KiCad project to keep designing. Without an account you can make 2 standard diagrams a day per network, and a free account gets 3 credits a day.
How the circuit diagram maker works
- 01Describe the circuit. Write it the way you would explain it to a colleague: the supply, the parts, their values and how they connect. Or switch to From photo and upload a picture of a sketch, a textbook figure or a screenshot.
- 02The AI writes a drawing plan, and the engine draws it. The model never draws pixels. It writes a short list of steps: a battery going up, a resistor going right, an op-amp with its − input here. ProtoFlow’s layout engine turns those steps into exact geometry, draws each part with its standard symbol, adds junction dots where three or more wires meet and rebuilds the netlist from the drawing. Then it checks for unconnected pins, shorted parts, overlaps and labels on top of wires, and sends any problem back to the model for one repair pass.
- 03Check it, change it, export it. Read the How it works, Calculations, Parts and Netlist tabs. Ask for a change in words, edit a value directly, switch between ANSI and IEC symbols or between paper, blueprint, dark and print themes, then download the format you need or open the circuit in ProtoFlow to turn it into a board.
Because the drawing comes from a parts-and-connections plan, the same diagram can become an SVG for a report, a SPICE netlist for a simulator and a KiCad schematic, and all three agree with each other.
How to describe a circuit so it draws well
The model fills in whatever you leave out, and every guess is a chance to draw something you did not mean. A good description reads like a short parts list with the connections spelled out.
- Name the parts and their values: “330 Ω”, “10 µF electrolytic”, “2N3904”, “LM358”.
- Give the supply: a 9 V battery, a 5 V rail, ±12 V, or 230 V mains through a transformer.
- Say how the parts connect: in series, in parallel, from the output to the − input, between VCC and the base.
- Name the inputs and outputs you want labelled, such as Vin, Vout, SDA or GPIO4.
- For a chip or a board, list the pins you use. The maker draws an IC as a box with only those pins, which keeps the drawing readable.
- Keep one diagram to one function. A power supply, an amplifier and a microcontroller each read better as their own diagram than as one sprawling sheet.
| Vague | Draws well | Why |
|---|---|---|
| “LED circuit” | “A 5 V supply, a 220 Ω resistor and a green LED in series, with an on/off switch.” | Names every part and the supply, so nothing is guessed. |
| “amplifier” | “An inverting op-amp amplifier with a gain of −10 using an LM358, 1 kΩ in and 10 kΩ feedback, + input to ground.” | Gives the topology, the gain and the part that sets it. |
| “555 blinker” | “A 555 astable on 9 V blinking an LED at about 1 Hz: 10 kΩ, 68 kΩ and 10 µF, 10 nF on CTRL, reset tied high.” | Fixes the timing parts, so the drawing and the maths agree. |
| “Arduino with a sensor” | “An Arduino Uno reading a 10 kΩ NTC thermistor on A0 through a 10 kΩ divider from 5V, and driving a buzzer on D8.” | Names the board pins, so the box shows only the pins in use. |
A real schematic, not an AI picture
There are two ways to get a circuit diagram out of AI. An image model paints something that looks like a schematic. A language model can instead describe the circuit as data, which a program then draws. The difference shows up the moment you read the result closely.
An image model has no idea which wire connects to which pin. Its diagrams often have resistors with the wrong number of terminals, labels that are almost words and lines that stop short of anything. They can look convincing in a thumbnail and still fall apart when you try to build from them, and you cannot change a value without generating a whole new picture.
This maker takes the second route. The model writes the circuit as parts and connections, and a deterministic engine does the drawing, so symbols are always the standard ones, text is always crisp and every line is a connection the netlist knows about. That is also why a diagram can be exported to KiCad or SPICE: there is a real circuit underneath it.
| Drawn from a netlist (this tool) | Generated as an image | |
|---|---|---|
| Symbols | Standard ANSI or IEC symbols, drawn the same way every time | Approximations that vary between images |
| Connections | Every wire is a net; junction dots are computed | Lines may stop short, cross or end nowhere |
| Labels and values | Real text, readable and searchable | Often garbled |
| Changing one value | Edit it; the drawing updates for free | Generate a new image and hope |
| Exports | SVG, PNG, PDF, KiCad, SPICE, BOM, circuitikz | A raster image |
| Checks | Unconnected pins, shorted parts and overlaps flagged | None |
What the checks cannot do is judge the design. The model can still choose a value that is wrong for your application or a circuit that does not do what you meant. Treat the result as a first draft from a quick colleague: read the netlist and the calculations before you build it.
What you get with every diagram
Each diagram comes with a short explanation of how the circuit works, the calculations behind its values, a parts list and the netlist. Exports are free; only asking the AI to draw or change a circuit uses credits.
| Export | File | Good for |
|---|---|---|
| SVG | .svg | Sharp at any size: reports, slides, web pages, Figma or Inkscape edits. |
| PNG | .png | Docs, chat, slides and anything that wants a plain image. |
.pdf | Printing, lab write-ups and attaching to a report. | |
| KiCad project | .zip | A schematic you can open in KiCad and carry on to a PCB. |
| SPICE netlist | .cir | Simulation in ngspice, LTspice or ProtoFlow. |
| Bill of materials | .csv | References, values and part numbers for ordering or a spreadsheet. |
| circuitikz | .tex | LaTeX papers and theses that typeset the circuit with the text. |
| Circuit JSON | .json | The drawing plan itself, to keep, edit or paste back in later. |
| Share link | URL | A read-only page anyone can open, copy and remix in the maker. |
| Open in ProtoFlow | desktop app | Turns the diagram into an editable schematic in the free ProtoFlow app. |
Circuit diagram symbols
Two symbol families cover almost every diagram you will meet. ANSI/IEEE symbols (IEEE 315) are standard in North America; IEC 60617 symbols are standard in Europe and much of the rest of the world. Most symbols are the same in both; the resistor is the one everyone notices. The maker draws ANSI by default. Switching the Style menu to IEC draws resistors, potentiometers, thermistors and LDRs as rectangles, a fuse as a box with a line through it, logic gates as rectangles marked &, ≥1 or =1, and the − plate of an electrolytic capacitor filled in. Inductors keep their row of humps and op-amps their triangle in both styles, and every other symbol is the same.
| Component | ANSI / IEEE | IEC |
|---|---|---|
| Resistor | Zigzag line | Plain rectangle |
| Potentiometer | Zigzag with an arrow (the wiper) pointing at it | Rectangle with an arrow pointing at it |
| Capacitor | Two parallel plates; polarised types curve the − plate and mark the + one | Two parallel plates; polarised types mark the + plate and often fill in the − plate |
| Inductor | A row of humps or loops | A row of humps (drawings from before 1996 may use a filled rectangle) |
| Diode | Triangle pointing at a bar; current flows toward the bar | Same |
| LED | Diode symbol with two arrows pointing away | Same |
| Battery | Long and short plates; the long plate is + | Same |
| Ground | Three shrinking horizontal lines; chassis ground adds slanted strokes | Same |
| Switch | A gap bridged by a hinged lever | Same |
| Transistor (BJT) | Base bar, collector and emitter, arrow on the emitter, usually in a circle | Same, often without the circle |
| Op-amp | Triangle with − and + inputs on the flat side | Rectangle marked ▷ ∞ in IEC 60617, though the triangle is widely used in IEC drawings too |
| Logic gates | Distinctive shapes: D-shaped AND, curved OR, bubble for NOT | Rectangles labelled & (AND), ≥1 (OR), =1 (XOR), with a small circle or triangle for inversion |
Two conventions matter as much as the symbols. A dot where wires meet means they are connected; wires that cross without a dot are not. And supply and ground symbols with the same name are connected even when no wire is drawn between them.
Circuit diagram vs schematic vs wiring diagram vs block diagram
In everyday use “circuit diagram” and “schematic” mean the same thing: a drawing of how parts connect electrically, made with symbols. The other diagram types answer different questions.
| Diagram | What it shows | Used for |
|---|---|---|
| Circuit diagram | Components as standard symbols and their electrical connections, arranged to be easy to follow. | Explaining how a circuit works: textbooks, homework, lab reports, datasheets. |
| Schematic (in EDA tools) | The same, plus reference designators, part numbers and footprints for every symbol. | The source a PCB layout and bill of materials are generated from. |
| Wiring diagram | Physical wires between real terminals, often with wire colours, gauges and connector pin positions. | Building or servicing a harness, a panel or household wiring. |
| Block diagram | Functional blocks (power, MCU, sensor, radio) and the signals between them, without components. | Planning a system before any circuit is drawn. |
| Breadboard or pictorial diagram | A drawing of the actual parts and jumper wires as they sit on a breadboard. | Beginner build guides and kits. |
Series and parallel circuits
Parts in series sit on one path, so the same current flows through each of them and their voltages add up to the supply. Resistances in series add: R = R1 + R2. The LED series circuit and the voltage divider are series circuits.
Parts in parallel connect across the same two nodes, so they share the same voltage and their currents add up. Two resistors in parallel give R = R1 × R2 / (R1 + R2), always less than the smaller of the two. Most real circuits mix both: the Wheatstone bridge is two series pairs in parallel across one battery.
To draw either, say it in the description: “three 1 kΩ resistors in parallel across a 5 V supply” draws differently from “three 1 kΩ resistors in series”.
From circuit diagram to PCB
A circuit diagram is where a board starts. When you want to build one, Open in ProtoFlow sends the diagram to the free ProtoFlow desktop app for Windows, macOS and Linux, where it becomes an editable schematic. From there the same project goes all the way to manufacturing:
- pick real parts from LCSC, DigiKey and Mouser, and run ERC on the schematic;
- lay out the PCB, route it with the auto-router and run DRC;
- simulate with SPICE (ngspice) before committing to a part;
- export Gerber X2, drill files and a JLCPCB-ready BOM and placement file;
- import and export KiCad, Altium and EAGLE projects.
The desktop app also drafts whole schematics from a written brief, and its AI agent can place and route the board while running the checks as it goes. As with this maker, the AI’s work is a draft for you to review. If a part has no symbol or footprint yet, the AI part generator builds both from a part number or datasheet, and the documentation walks through the full flow.
Who uses a circuit diagram maker
- Students draw circuits for homework and lab reports, and use the calculations tab to check their own working.
- Teachers make clean figures for worksheets and slides, and change one value to make the next version of a problem.
- Makers sketch a project before wiring it, and keep the diagram with the build notes so they can fix it later.
- Engineers rough out a sub-circuit for a design review or an email, then take it into KiCad or ProtoFlow when it becomes real.
- Technical writers produce consistent SVG figures for documentation and application notes, or circuitikz for LaTeX.
Credits and free use
Opening examples, editing, restyling and exporting are free. Asking the AI to draw or change a circuit costs usage credits, the same credits your ProtoFlow account uses for other AI tools on this site. Signed out you get a small daily allowance per network; a free account gets a larger one each day, and paid plans get a monthly allowance. Your wallet is only used after that.
| Who | Included |
|---|---|
| No account | 2 standard diagrams a day, shared by everyone on your network |
| Free account | 3 credits a day (3 standard diagrams, or 1 at Pro quality) |
| Pro plan | 60 credits a month |
| Max plan | 200 credits a month |
| Ultra plan | 600 credits a month |
| Action | Cost |
|---|---|
| Generate or change a diagram, standard quality | 1 credit |
| Generate or change a diagram, Pro quality (free account needed) | 3 credits |
| Start from a photo or sketch (free account needed) | +1 credit |
| Open an example, edit values, change style, undo | Free |
| Every export and share link | Free |
After the allowance, generations use credits from your wallet; credits you buy cost $0.10 each. If a generation fails, it does not count against you: the credits or the free try come back, for up to 3 failed generations a day. Daily allowances reset at midnight UTC and monthly ones on the first of the month. To keep the tool fair, an account can run up to 6 generations a minute and 150 a day, and signed-out use has a site-wide daily limit; when that is reached, signing in still works. Plans and credit packs are on the pricing page.
Tips for clean diagrams
- Signal flow left to right: ask for the input on the left and the output on the right.
- Supply at the top, ground at the bottom. Supply and ground symbols beat long rails across the page.
- Use net labels such as VCC, SDA or OUT instead of long wires between distant parts.
- Draw ICs and boards with only the pins in use, and list them in the order they should appear on each side.
- Give every part a value. A diagram with “R1” and no value is half a diagram.
- Split a large circuit into blocks and make a diagram for each.
- Check the Netlist tab: every net should have the pins you expect, and none should have just one.
- Use the print theme for black-and-white documents and SVG for anything that will be scaled.
Frequently asked questions
Is the circuit diagram maker free?
Yes, to start. Without an account you can make 2 standard diagrams a day, counted per network, so people on a shared connection such as a school or office network share them. Signing in with a free ProtoFlow account replaces that with 3 credits a day (3 standard diagrams, or 1 at Pro quality) and unlocks Pro quality and From photo. Opening the examples, editing values, changing the style and every export are always free. Beyond the daily allowance, generations use usage credits from your ProtoFlow wallet.
How many credits does a circuit diagram cost?
A standard generation, or a change you ask for in words, costs 1 credit. Pro quality, for bigger circuits, costs 3 credits, and a photo or sketch adds 1 credit. If a generation fails, it does not count against you: the credits or the free try come back, for up to 3 failed generations a day. Credits you buy cost $0.10 each.
How do I make a circuit diagram online?
Describe the circuit in the box at the top of this page, with the parts, values and supply voltage, and press Generate. Check the drawing and the netlist, fix any value for free in the Parts tab, then download SVG, PNG or PDF, or a KiCad project.
Is the circuit diagram electrically correct?
The drawing is checked; the design is not guaranteed. Every line is a real connection, and the maker flags unconnected pins, shorted parts and overlaps before you see the result. It cannot know whether the circuit does what you meant, so check the netlist, the values and the calculations the way you would check a colleague's first draft.
Can I export to KiCad, EasyEDA or Altium?
You can download a KiCad project directly. For Altium, EAGLE or PADS, open the diagram in the free ProtoFlow desktop app, which exports to those formats. EasyEDA can import KiCad projects.
Can I edit the diagram after it is generated?
Yes. Ask for a change in plain English, such as "use a 5 V supply" or "add a decoupling capacitor" (1 credit at standard quality), or edit a part's value for free in the Parts tab. Style changes and undo are free too.
Does it use ANSI or IEC symbols?
Both. Diagrams use ANSI/IEEE symbols by default. Switch to IEC in the Style menu to draw resistors as rectangles, fuses as boxes and logic gates as rectangles marked &, ≥1 and =1, the European convention. Op-amps keep their triangle and inductors their row of humps in both styles.
What is the difference between a schematic and a wiring diagram?
A schematic shows how parts connect electrically, using symbols, with no attention to where the parts physically sit. A wiring diagram shows the physical wires between real terminals, often with colours and connector pins, so someone can build or repair the wiring.
Can it draw Arduino and ESP32 circuits?
Yes. A development board is drawn as a box with only the pins your circuit uses, labelled with their names, such as 5V, A0 or GPIO4. Name the pins in your description for the cleanest result.
Can it draw logic gate circuits?
Yes: AND, OR, NAND, NOR, XOR, XNOR, NOT and buffers, with two to four inputs. The half adder example shows an XOR and an AND gate sharing two inputs.
Can I simulate the circuit?
Download the SPICE netlist and run it in ngspice or LTspice, or open the diagram in ProtoFlow, which runs ngspice simulations from the schematic. Results depend on the component models; chips drawn as boxes need a model added before they simulate.
Can I turn the circuit diagram into a PCB?
Yes. Open in ProtoFlow sends the diagram to the free desktop app, where you pick real parts, lay out and route the board, run DRC and export Gerbers. You can also download the KiCad project and continue in KiCad.
Can ChatGPT make a circuit diagram?
A chat assistant can describe a circuit well and can write code for drawing libraries such as schemdraw or circuitikz, which you then run yourself. Image generators tend to produce pictures that look like schematics, with garbled labels and wires that go nowhere. This tool uses a model to write a structured drawing plan, then draws and checks it with a deterministic engine.
Can I use the diagrams in reports or commercial work?
Yes. ProtoFlow's terms say you own your designs, so you can use the diagrams in coursework, papers, documentation and products. Check the circuit before you rely on it.
Do I need an account?
Not for your first 2 standard diagrams each day (counted per network), and never for opening examples, editing or exporting. Signing in with a free account (verify your email first) swaps the signed-out allowance for a bigger one, 3 credits a day, and unlocks Pro quality and From photo.
Can I turn a photo or hand-drawn sketch into a schematic?
Yes, with a free account. Choose From photo and upload a photo, scan or screenshot of the circuit; it costs 1 credit on top of the generation. A clear, well-lit sketch with the values written on it works best, and you should compare the result with the original.
Related tools
- Voltage divider calculatorOutput voltage, or the E24/E96 resistor pair for a target.
- Resistor color code calculator4, 5 and 6-band codes, plus SMD markings.
- PCB trace width calculatorIPC-2221 width for a current and temperature rise.
- Online Gerber viewerCheck a board’s Gerber files before you order.
- AI part generatorA schematic symbol and PCB footprint from a part number or datasheet.
- Circuit diagram generators comparedDrawing tools and engineering schematic tools, side by side.
Start from an example: Series LED circuit, Voltage divider, 555 timer astable LED flasher, RC low-pass filter.
Turn the diagram into a board
ProtoFlow is free AI PCB design software for Windows, macOS and Linux: schematic with real parts, PCB layout with an auto-router, SPICE simulation and Gerber files, with KiCad, Altium and EAGLE import and export.
Free to start. No card required.

