Circuit Diagram Generators in 2026: Drawing Tools vs Engineering Schematics
"Circuit diagram generator" covers two different needs. One is a picture of a circuit for a report, a slide or a lab write-up. The other is an engineering schematic, where every symbol is a real part and every line is a net that carries into PCB layout. We compared 12 tools across both needs and list them alphabetically, not by preference. Each one gets the same facts: what it makes, what is free, where it runs, what it exports, who it suits and where it falls short. The only hands-on results here are ProtoFlow's.
An example of one of the engineering schematic tools below: ProtoFlow drafting an editable circuit with real parts from a written description.
Quick answer
It depends on what the diagram is for. For a figure in a report, slide or lab write-up, a drawing tool fits. ProtoFlow's own AI circuit diagram maker (protoflow.ai/tools/circuit-diagram-maker) draws one in the browser from a plain-English description, with standard symbols and a netlist checked for unconnected pins and shorts, and exports SVG, PNG, PDF or a KiCad project. It is free to start: 2 standard diagrams a day per network without an account, or 3 credits a day with a free account. ChatDiagram also draws circuit diagrams from text (10 free AI credits a month), Circuit Diagram (circuit-diagram.org) is free with no account needed, and Lucidchart has electrical symbol libraries. For a circuit you will build, you need an engineering schematic, where every symbol is a part and every line is a net: EasyEDA and KiCad 10 are free editors without built-in AI, Flux sells an AI engineer in the browser after a trial, and PCBEditor and Trace generate schematics from a description. The ProtoFlow desktop app does that too, for free, and carries the same design through layout, autorouting, SPICE simulation and Gerbers.
Circuit diagram generators, listed alphabetically (vendor pages read October 25 and 26, 2026)
Tool
What you get
Generates from text
Simulation
Path to a PCB
What is free
Runs on
ChatDiagram
Drawing: circuit, single-line, ladder logic, breadboard and other diagram images
Yes, from plain English
Not listed
None listed; exports SVG, PNG, PDF
10 AI credits a month, no card; Pro $15.9/month
Browser
Circuit Diagram (circuit-diagram.org)
Drawing: circuit diagrams you draw by hand
No, manual editor
Built-in simulator (beta)
Netlist export; no PCB layout listed
Free; account only to save online
Browser, plus a download for offline use
CircuitLab
Simulation: schematics you draw and simulate
No, manual editor
Analog, digital and frequency-domain
No PCB layout listed; exports PDF, PNG, EPS, SVG
Paid from $24/year (10 items per schematic); Student Edition free where the school has a site license
Browser
DigiKey Scheme-It
Documentation: schematics and block diagrams with DigiKey part numbers and a BOM
Full editor; 5 Basic + 10 Pro AI messages a day; no card, no expiry
Windows, macOS, Linux desktop
ProtoFlow AI circuit diagram maker
Drawing backed by a checked netlist: circuit diagrams with standard ANSI or IEC symbols
Yes, from plain English, or from a photo of a sketch with a free account
SPICE netlist export for ngspice or LTspice
KiCad project export, or open in the ProtoFlow desktop app; also SVG, PNG, PDF, BOM, circuitikz
2 standard diagrams a day per network without an account, or 3 credits a day with a free account; then usage credits
Browser
Trace
Engineering: AI agent and schematic and PCB editor
Yes, multi-sheet schematics from text
Not listed
Places and routes; Gerber, BOM, pick-and-place (Pro)
Editor free. AI: 7-day trial with $30 credit, card required
Desktop (Windows, macOS, Linux); Altium and KiCad plugin; CLI
Prices and Plan Limits, Checked Against Vendor Pages
Each row links to the vendor page it came from and shows the date we last read that page. Vendors change pricing often, so check the link before you buy.
Micro $24/year or $2/month, limited to 10 items per schematic; Student Edition free to students and staff at schools with a $2,400/year site license (.edu email required)
2 standard diagrams a day per network without an account; 3 credits a day with a free account; a standard diagram costs 1 credit, Pro quality 3; exports free
The tools are listed alphabetically and each gets the same six fields: what it makes, what is free, where it runs, what it exports, who it suits and where it falls short.
Every price and limit comes from the vendor's own pricing, product, help or documentation page, read on October 25 or 26, 2026. The price table above links each one to its page. Plans change often, so check the linked page before you commit.
The hands-on results on this page are ProtoFlow's only, from runs we published and checked in KiCad. We have not run the other tools on the same circuit, so this page makes no claim that one tool's output is better than another's.
Drawing or engineering schematic: decide this first
A drawing tool places symbols on a canvas and gives you a picture. If the picture is the deliverable, for homework, documentation, a slide or a forum post, a drawing tool is the right tool, and it is usually faster: ChatDiagram, Circuit Diagram, Lucidchart and ProtoFlow's AI circuit diagram maker fit here, and CircuitLab and DigiKey Scheme-It add simulation and part numbers.
An engineering tool builds a real schematic underneath: every symbol is a part with a footprint, every line is a net, and the design can move into PCB layout and manufacturing files. If the circuit will become a board, start here. EasyEDA and KiCad 10 are free editors where you draw the schematic yourself; Flux, PCBEditor, ProtoFlow and Trace add AI that drafts or edits it.
Three drawing tools offer a partial bridge. Circuit Diagram exports a netlist, DigiKey Scheme-It exports a KiCad schematic in beta, and ProtoFlow's AI circuit diagram maker exports a KiCad project or sends the diagram to the ProtoFlow desktop app. Each gives an EDA tool a starting point, not a board.
Where circuit diagram generators fall short
A drawing does not know whether the circuit works. Apart from ProtoFlow's AI circuit diagram maker, which flags unconnected pins and shorted parts in the drawing, none of the drawing tools here lists an electrical rules check, and an AI-drawn diagram can look right and still be wired wrong. No drawing check can tell whether the values suit your design, so check every connection and value yourself before the figure goes into a report.
Pictures do not become boards. Image and PDF exports have to be redrawn in an EDA tool before you can lay out a PCB.
AI schematics are drafts. PCBEditor's own review of six AI-generated boards found one right on the first run and four after a fix, and Flux says its AI Auto-Layout is not designed to fully autoroute every class of board. Review parts, pin maps, power and footprints, and run ERC in the tool you will build from.
Free AI is usually small or temporary. ChatDiagram's free plan is 10 AI credits a month, ProtoFlow's AI circuit diagram maker gives 2 standard diagrams a day per network signed out (3 credits a day with a free account), PCBEditor is free while it is in beta, and the ProtoFlow desktop app's free plan allows 15 AI messages a day. Flux and Trace end free AI after a trial.
ChatDiagram
What it makes: diagram images from a plain-English description. It lists 52 diagram types, among them circuit, single-line, ladder logic, logic gate and breadboard diagrams, and says circuit requests go to a dedicated circuit engine.
Free tier: 10 AI credits a month at $0, with no card. Pro is $15.9 a month with 500 AI credits a month.
Platform: browser.
Exports: SVG, PNG and PDF.
Best for: a quick circuit figure from a text description.
Where it falls short: it draws pictures. No netlist, parts or PCB output is listed, so a circuit that will become a board has to be redrawn in an EDA tool. The free plan is 10 AI credits a month.
Circuit Diagram (circuit-diagram.org)
What it makes: circuit diagrams you draw by hand in a free editor, with a built-in circuit simulator marked beta.
Free tier: free. You sign in only to save circuits to an account; otherwise you download them to keep offline.
Platform: browser, plus a download for offline use.
Exports: vector images and a selection of other formats, including a netlist.
Best for: a clean, free circuit figure drawn by hand.
Where it falls short: no AI, so you place every symbol yourself, and no PCB layout is listed. The simulator is marked beta, and the netlist export gives an EDA tool a starting point, not a board.
CircuitLab
What it makes: schematics you draw in the browser and simulate, with analog, digital and frequency-domain (small-signal) analysis and SPICE-like models.
Free tier: every plan we found is paid. Micro is $24 a year and limited to 10 items per schematic, Hacker Lite is $79 a year, and Pro is $399 a year for commercial use. Students and staff at a school with a CircuitLab site license ($2,400 a year for the school) get the Student Edition with an .edu email.
Platform: browser, no install.
Exports: vector PDF, PNG, EPS and SVG.
Best for: simulating a coursework circuit and putting the schematic in a report.
Where it falls short: no AI, and no PCB layout or netlist export is listed. The Micro plan caps a schematic at 10 items, and the free student route depends on your school paying for a site license.
DigiKey Scheme-It
What it makes: schematics and block diagrams tied to DigiKey's catalog. You can assign orderable part numbers, and a built-in BOM manager tracks the parts in a design.
Free tier: free to use as much as you like. You register only to save and share designs.
Platform: browser.
Exports: PDF and PNG, plus a KiCad export in beta that bundles library, project and schematic files in a ZIP.
Best for: documentation schematics and block diagrams with real part numbers and a parts list.
Where it falls short: no AI, and no simulation or PCB layout is listed. The KiCad export is in beta and leaves out diagram symbols, system blocks and system icons.
EasyEDA
What it makes: engineering schematics and PCBs in a full editor with no built-in AI. EasyEDA Pro has had built-in simulation since version 3.2, with Simulide and ngspice engines.
Free tier: a "Free Forever" plan for individuals, with commercial use allowed and 0.5 GB of cloud storage. Ads show in the free editor. Premium is $19.9 a month, billed yearly.
Platform: browser and desktop app.
Exports: Gerber, BOM, pick-and-place and Altium-format files. It imports KiCad, Altium, EAGLE, PADS and Allegro/OrCAD designs.
Best for: a complete free editor when you are happy to draw the circuit yourself.
Where it falls short: no built-in AI. The free editor shows ads and keeps libraries public, and EasyEDA's docs say Pro and Std files are not interoperable.
Flux
What it makes: engineering schematics and PCBs in a browser editor with what Flux calls an "AI hardware engineer for end to end design". AI use is metered in Agent Compute Units (ACUs).
Free tier: none. New individual plans start with a 7- or 14-day trial, depending on the offer, with limited AI. After the trial Flux says a paid plan is needed to edit private projects, export them and use AI. Explore is $50 a month, or $40 a month billed yearly, with 40 ACUs a month.
Platform: browser.
Exports: Gerber, BOM, pick-and-place, IPC-2581C, ODB++, GenCAD, EDIF netlist, IPC-D-356, STEP, STL and its own .flx file. Its export list has no KiCad or Altium project format.
Best for: teams who want one shared browser workspace and are ready to pay after the trial.
Where it falls short: not free after the trial, and AI is capped by the ACUs on your plan. Flux says its AI Auto-Layout is not designed to fully autoroute every class of board.
KiCad 10
What it makes: engineering schematics and PCBs in the standard free, open-source editor. It runs ngspice simulation from the schematic. It has no built-in AI; community MCP servers, such as the MIT-licensed KiCAD-MCP-Server, let assistants such as Claude read and edit a KiCad project.
Free tier: fully free and open source under GPL version 3 or later; the libraries are CC-BY-SA 4.0. The current stable release is 10.0.7, from October 7, 2026.
Platform: Windows, macOS and Linux.
Exports: Gerber, drill files, IPC-2581, ODB++, position (pick-and-place) files, BOM, IPC-D-356 netlists and STEP.
Best for: a complete free editor when you want to draw the circuit yourself, or wire up AI help yourself.
Where it falls short: no built-in AI, and no full-board autorouter: KiCad's router finishes the connections you select, and routing a whole board needs an add-on such as Freerouting. AI help comes from community MCP servers you install and connect yourself.
Lucidchart
What it makes: general diagrams. Its circuit page offers electrical shape libraries (power sources, transistors, relays, logic gates and other standard symbols) and circuit templates, and Lucid offers a text-to-diagram AI generator.
Free tier: Lucid lists free and premium plans; check its pricing page for the current free-plan limits.
Platform: browser.
Exports: image files and presentations. Paid Individual, Team and Enterprise accounts can export to Visio.
Best for: teams that already use Lucidchart and want a circuit figure next to their other diagrams.
Where it falls short: it is a general diagram tool. Its circuit page lists symbols and templates but no netlist, simulation or PCB output, and Visio export needs a paid plan.
PCBEditor
What it makes: engineering schematics and PCBs in an online editor in beta. It generates a schematic and PCB from a plain-language description, says it picks real parts with verified pin maps, and offers AI routing, placement and footprint generation from datasheets.
Free tier: free during the beta, with no card. The editor and viewer work without an account; AI generation needs a sign-in. No usage limits are published.
Platform: browser.
Exports: Gerber and KiCad.
Best for: a quick, free look at prompt-to-schematic in the browser.
Where it falls short: it is a beta with no published limits. Its own review of six AI-generated boards (October 2026) found one right on the first run and four after a fix, and its privacy policy does not say whether designs are used to train AI.
ProtoFlow (desktop app)
What it makes: engineering schematics and PCBs in a desktop app with AI built in. You describe a circuit and it drafts an editable schematic with real LCSC, DigiKey and Mouser parts. ERC checks it, and the same project goes through PCB layout with an auto-router, SPICE simulation, DRC and manufacturing files. Its AI agent, ProtoFlow Studio, can also place and route a board.
Free tier: the full editor with no card and no expiry, 5 Basic and 10 Pro AI messages a day, and 10 AI part-generator units a month. Pro models, live collaboration and file uploads in the AI chat are paid. Pro is $19.99 a month with a 7-day trial.
Platform: Windows, macOS and Linux. Project files stay on your computer; the AI features send requests to hosted models.
Exports: Gerber X2 with a job file, Excellon drill files, and BOM and placement files for JLCPCB assembly. It opens KiCad, Altium and EAGLE projects and exports KiCad, Altium, EAGLE, PADS and EDIF.
Best for: a circuit you plan to build, when you want to start from a written description and carry on to a board in the same app.
Where it falls short: it needs a desktop install; for a figure in a report, ProtoFlow's browser circuit diagram maker below is the lighter option. The free AI allowance is small, it does no signal-integrity analysis, and every AI draft needs an engineer's review. Our terms let us change or end the free tier, and AI training on prompts and designs is on by default unless you opt out (EU and UK users are opted out). There are few independent reviews of ProtoFlow yet.
What we ran: our published results used ProtoFlow Studio with Claude Opus 5.5, a paid setup, not the free plan's daily messages. On LG AI Research's public PCBWorld-Bench (October 13, 2026, one attempt per board, every attempt counted), 98 of 99 small boards came back clean under KiCad's design-rule check; the one miss was a ProtoFlow file-save bug, and that board was clean once it was fixed. All 30 medium-board attempts were clean. On IO Rodeo's open-source Rodeostat (October 16, 2026), it made all 372 connections with zero KiCad errors and no part moved. That is evidence for those boards only.
ProtoFlow AI circuit diagram maker
What it makes: circuit diagrams in the browser from a plain-English description or a photo of a sketch. A model writes the circuit as parts and connections, and a deterministic engine draws it with standard ANSI or IEC symbols, rebuilds the netlist from the drawing and flags unconnected pins, shorted parts and overlaps. Each diagram comes with an explanation, its calculations and a parts list.
Free tier: 2 standard diagrams a day without an account, counted per network, so people on a shared connection share them. A free ProtoFlow account gets 3 credits a day instead and unlocks Pro quality and photo input; a standard diagram costs 1 credit and Pro quality 3. Paid ProtoFlow plans include a monthly allowance, and after that generations use usage credits. Opening examples, editing values and exporting are free.
Platform: browser, no install.
Exports: SVG, PNG, PDF, a KiCad project, a SPICE netlist, a BOM CSV, circuitikz and share links. Open in ProtoFlow sends the diagram to the desktop app.
Best for: a clean figure for a report, slide or lab write-up, drawn from a description, that you may later want to simulate or turn into a board.
Where it falls short: one diagram at a time, not a multi-sheet design, and the free allowance is a few diagrams a day. Its checks catch wiring mistakes in the drawing, not design mistakes, so values still need checking. Parts carry values but no footprints, so a board needs the desktop app or KiCad. It is new, with no independent reviews yet.
Trace
What it makes: engineering schematics and boards through an AI agent that generates hierarchical multi-sheet schematics from natural language, places and routes multi-layer boards, and exports Gerbers.
Free tier: the schematic and PCB editor stay free. AI is a 7-day trial with $30 of AI credit and a card on file. After that, Pro is $29.99 a month (about 75 agent requests) or pay-as-you-go from $20.
Platform: a desktop app for Windows, macOS and Linux, a plugin for Altium and KiCad, and a CLI.
Exports: Gerber, BOM and pick-and-place on Pro.
Best for: Altium and KiCad users who want an agent inside the tool they already use.
Where it falls short: no ongoing free AI, and the trial needs a card. On individual plans Trace collects product-improvement data by default, including design data, and its docs say routing on dense boards can come back incomplete.
Decision Matrix
If you need
Look at (alphabetical)
Why
A figure for a report, slide or lab write-up
ChatDiagram, Circuit Diagram (circuit-diagram.org), Lucidchart, ProtoFlow AI circuit diagram maker
Drawing tools that export images. ProtoFlow's maker drafts from text in the browser, checks the wiring and also exports KiCad and SPICE; ChatDiagram drafts from text; Circuit Diagram is free with no account; Lucidchart has electrical symbol libraries.
A schematic you can simulate in the browser
Circuit Diagram (beta simulator), CircuitLab
CircuitLab simulates analog, digital and frequency-domain circuits on paid plans; Circuit Diagram's simulator is free and marked beta.
A documentation schematic tied to real part numbers
DigiKey Scheme-It
Free, with DigiKey part numbers and a BOM manager. KiCad export is in beta.
A circuit you will build, drawn by you, for free
EasyEDA, KiCad 10
Free engineering editors with simulation and PCB layout, without built-in AI.
A circuit you will build, generated from a description
Flux, PCBEditor, ProtoFlow, Trace
ProtoFlow drafts an editable schematic with real parts and carries it through layout, autorouting, SPICE simulation and Gerbers in one free desktop app. PCBEditor is a free browser beta; Flux and Trace charge for AI after a trial.
One shared browser workspace for a team
Flux
Built for shared browser work, and paid after the trial.
How to Try These on Your Own Circuit
01Decide what the diagram is for: a figure people will look at, or a circuit you will build.
02For a figure, draw the same circuit in two drawing tools and check how each export looks in your document.
03For a circuit you will build, write a one-paragraph description and run it through two or three engineering tools, or draw it yourself in a free editor.
04Run ERC in the tool you will build from, and check every part, pin and power connection yourself.
05Have an engineer review the schematic, and later the layout, before you order boards.
What We Checked and What We Ran
Reviewed on: 2026-10-26
Methodology
Read the vendors' own pages for ChatDiagram, Circuit Diagram, CircuitLab, DigiKey Scheme-It and Lucidchart, and the simulation docs for EasyEDA and KiCad, on October 26, 2026. Facts on EasyEDA, Flux, KiCad, PCBEditor and Trace otherwise come from our October 25 and 26, 2026 checks of their own pages. ProtoFlow's AI circuit diagram maker is our own tool; its allowances are the defaults its page listed on November 2, 2026. The price table links every plan limit to its page.
Split the 12 tools by what the output is made of, a drawing or an engineering schematic, and listed them alphabetically with the same six fields each.
Where a vendor page did not state something, the table says "Not listed" instead of guessing.
Hands-on results are ProtoFlow's only, from runs we published and checked in KiCad. We have not run the other tools on the same boards, so nothing here claims one tool's output is better than another's.
Findings
None of the drawing, documentation or simulation tools here lists PCB layout. Three offer a partial bridge: Circuit Diagram exports a netlist, DigiKey Scheme-It exports a KiCad schematic in beta, and ProtoFlow's AI circuit diagram maker exports a KiCad project and a SPICE netlist and opens in the ProtoFlow desktop app.
ProtoFlow's AI circuit diagram maker gives 2 standard diagrams a day per network without an account, or 3 credits a day with a free account, with SVG, PNG, PDF and KiCad export.
CircuitLab's cheapest plan, Micro, is $24 a year and limited to 10 items per schematic. Students get its Student Edition free only where their school pays for a site license.
ChatDiagram's free plan gives 10 AI credits a month, with SVG, PNG and PDF export.
Among the engineering tools, the free AI options are PCBEditor (a free beta with no published limits) and ProtoFlow (daily message limits). Flux has no free plan, and Trace's AI is a 7-day trial that needs a card.
PCBWorld-Bench, October 13, 2026: ProtoFlow Studio with Claude Opus 5.5 (a paid setup) left 98 of 99 small boards clean under KiCad's design-rule check on one attempt each, and all 30 medium-board attempts clean. Evidence for those boards only.
Frequently Asked Questions
What is the best free circuit diagram generator?
It depends on the job. For a figure, ProtoFlow's AI circuit diagram maker drafts one from text in the browser (2 standard diagrams a day per network without an account), Circuit Diagram (circuit-diagram.org) is free with no account needed, and ChatDiagram drafts diagrams from text with 10 free AI credits a month. For a circuit you will build, EasyEDA and KiCad 10 are free engineering editors without AI, and PCBEditor is a free browser beta that generates a schematic from a description. If you want one free tool that takes a prompt through schematic, layout, autorouting, SPICE simulation and Gerbers, ProtoFlow does all of that in one desktop app, with daily AI limits.
Can AI generate a circuit diagram?
Yes, in two different senses. ChatDiagram, and Lucidchart's text-to-diagram AI, draw a picture. ProtoFlow's AI circuit diagram maker draws one too, from a netlist it checks, so it can also export KiCad and SPICE. Flux sells an "AI hardware engineer" in its browser editor after a trial, and PCBEditor, ProtoFlow and Trace generate an engineering schematic with parts and nets behind the symbols. Either way, check the result: an AI drawing can look right and still be wired wrong.
What is the difference between a circuit diagram and a schematic?
In everyday use the words overlap. The difference that matters when you pick a tool is what the file is made of: a drawing is an illustration, while a schematic in an EDA tool carries symbols tied to parts and footprints, and nets that drive PCB layout.
Can I turn a generated circuit diagram into a PCB?
Only if there is a schematic underneath. The engineering tools here (EasyEDA, Flux, KiCad 10, PCBEditor, ProtoFlow and Trace) carry parts and nets into PCB layout. Circuit Diagram exports a netlist and DigiKey Scheme-It exports a KiCad schematic in beta, which give an EDA tool a starting point. ProtoFlow's AI circuit diagram maker exports a KiCad project and opens in the ProtoFlow desktop app. Image exports from ChatDiagram or Lucidchart have to be redrawn.
Is there a free AI circuit diagram generator?
For pictures, ProtoFlow's AI circuit diagram maker gives 2 standard diagrams a day per network without an account, or 3 credits a day with a free account, and ChatDiagram's free plan gives 10 AI credits a month. For engineering schematics, PCBEditor is free while in beta (AI needs a sign-in), and ProtoFlow has a free plan with 5 Basic and 10 Pro AI messages a day. Flux has no free plan, and Trace's AI is a 7-day trial that needs a card.
Which circuit diagram tool suits students?
For lab reports, a drawing tool: ProtoFlow's AI circuit diagram maker drafts the figure from a description in the browser and shows its calculations, and Circuit Diagram is free to draw by hand. For simulation coursework, CircuitLab's Student Edition is free if your school has a site license. For a board you will build, KiCad 10 or ProtoFlow, both free; our guide to PCB design software for students compares the options.
Is ProtoFlow really free?
The free plan has the full editor, with no card and no expiry. AI is limited to 5 Basic and 10 Pro messages a day and 10 part-generator units a month. Pro models, live collaboration and file uploads in the AI chat are paid; Pro is $19.99 a month with a 7-day trial. ProtoFlow may use AI prompts and design data to train its models unless you turn off "Help improve ProtoFlow AI" in the app's privacy settings; for EU and UK users it is off unless they opt in.
