Perfboard pattern editor
Before you solder, draw your perfboard layout in the browser first
Patterndo is a free web editor where you place parts and draw wiring on a perfboard, check it in 2D and 3D, and catch connection mistakes with live simulation and diagnostics. No sign-up and no install.
Patterndo at a glance
- Part types
- 12
- Built-in IC models
- 31
- Max board size
- 161×121
- Sign-up
- Not needed
The problem Patterndo tackles
If you solder straight from a schematic, it is easy to run short of parts or end up with tangled wiring. Soldering is hard to undo, so checking the layout and connections on screen first is the cheapest way to prevent mistakes.
Catch mistakes before soldering
The diagnostics panel warns you ahead of time about overlapping parts, crossing wires, power shorts, and reversed polarity.
Same orientation as the real board
The component side and copper side are mirrored. One flip shows you the side you will actually solder, exactly as it will look.
See the connections work
Simulation calculates and shows the voltage at every connection point, so you can work out "the wiring looks right, so why does it not light up?" before you solder.
Draw perfboard layouts in your browser
A perfboard layout shows which hole each part goes into on a perfboard with holes on a 2.54 mm pitch, and which holes are joined by solder bridges or jumpers. A schematic only tells you the connections, not the positions, so drawing the layout before soldering lets you plan where parts fit, how long the wires run, and how many jumpers you need.
A layout drawn on paper, graph paper, Excel, or PowerPoint has to be redrawn on every change, and you can only check the connections by eye. Patterndo is a free site built specifically for drawing perfboard layouts: drag a part and its wiring follows, and it works out the nets from the wires you draw to flag shorts and missing connections. It also shows the copper side you will solder, mirrored exactly as it will look.
Import a schematic image or a KiCad or SPICE netlist and the connections you still need to make are drawn as dashed lines (a ratsnest) between board pins, so moving a schematic onto a perfboard goes quickly too.
Key features
The core features available in the editor. Detailed usage for each is covered in the features page and the guides.
2D · 3D views
Flip between the component and copper sides to check the board in the same orientation as a real perfboard, and rotate it in 3D to judge the part layout.
Live simulation
Turn the power on and it calculates the voltage and current at every connection point, showing LEDs lighting, seven-segment displays, and logic output states.
Diagnostics (DRC)
Lists and marks problems you should catch before soldering, such as crossing wires, VCC–GND shorts, polarity errors, and jumper conflicts.
Auto-rewire
Keeps the pin connections as they are and recalculates wires and jumpers to cut the number of jumpers and bends. One undo puts everything back.
Import a schematic or netlist
Reads connections from a KiCad or SPICE netlist or a schematic photo, draws the links still to make between board pins, and places missing parts.
Share link · RAW JSON
Share a board with a single link, or download it as a JSON file to back it up and load it again.
Touch & pen input
Supports tablet work with pinch zoom, long-press menus, pen auto-wiring, and an eraser-button switch.
Shortcuts & command search
Work without taking your hand off the mouse, using left-hand tool keys and Ctrl+K command search.
How to get started
If you are new, these four steps are enough to finish your first circuit.
Open the editor
An empty perfboard opens right away, no sign-up needed. Change the board size and supply voltage in [Board settings].
Place parts
Press A or use [Add part] to search for resistors, LEDs, and ICs and place them, then press R to rotate.
Wire them up
W is wire and D is jumper. Draw a line along the holes and the connections (nets) are worked out automatically.
Check and save
Check voltage and current with [Sim], fix the warnings in the diagnostics panel, then save with a share link or RAW JSON.
Who it is for
Beginners & students
Practice turning a schematic into a real perfboard layout over and over, safely and without wasting parts.
Hobbyists
Rearrange parts as many times as you like before soldering, and find neat wiring with few jumpers.
Teachers & clubs
Hand out assignment boards with a share link, and explain or review connections while looking at the same screen.
Guides to read first
58 guides, from soldering basics and reading layout diagrams to choosing parts and using Patterndo.
How to Draw a Perfboard Layout: Placing Parts, Wiring, and Jumpers Step by Step
A step-by-step guide for first-timers: what to prepare, the order to place power rails and parts, how to route wires and jumpers, reviewing the copper side, and common questions.
Using PatterndoGetting Started with Patterndo: Build an LED Circuit
Follow along from scratch: add parts in the Patterndo editor, wire up an LED circuit, then check voltage and current with the simulation.
Perfboard basicsMoving a Schematic onto Perfboard in 7 Steps
A seven-step walkthrough of deciding part placement, power rails, and wiring order from a schematic, including tips for shortening wires and reducing crossings.
Understanding partsLED Current-Limiting Resistors and Brightness Control
Why an LED needs a resistor, how to calculate the current-limiting resistor, choosing a standard value, checking power rating, and how brightness relates to current, with examples.
Ready-to-use calculators
Reading resistor values, choosing an LED resistor, and calculating a 555 timer frequency come up in every perfboard project. These calculators explain the working and formulas along with the answer.
Resistor Color Code Calculator
Pick the color bands of a 4-band or 5-band resistor to get its value and tolerance, or enter a resistance to see the matching color bands.
LEDLED Resistor Calculator
Enter the supply voltage, LED forward voltage, and target current to calculate the current-limiting resistor, then see the actual current and heat when you switch to the nearest standard value.
OHMOhm's Law & Power Calculator
Know any two of voltage, current, resistance, and power and it calculates the other two. Prefixes like 4.7k and 100m can be typed in as they are.
DIVIDERVoltage Divider Calculator
Calculate the output voltage from the input voltage and resistors R1 and R2, and see how far the output drops when you connect a load resistance.
555555 Timer Calculator (Astable & Monostable)
Calculate the frequency, period, and duty cycle of an NE555 astable oscillator from R1, R2, and C, or the output time of a monostable (one-shot) from R and C.
RCRC Time Constant & Cutoff Frequency Calculator
Calculate the time constant τ, charge and discharge times, and the cutoff frequency of an RC low-pass filter from a resistor and capacitor value.
NETWORKSeries & Parallel Resistor Calculator
Calculate the combined resistance and current split of resistors connected in series or parallel. Handy for making a target value from two standard resistors.
Frequently asked questions
Is Patterndo free? Do I need to sign up?
It is free, and you can use it right in your browser with no sign-up or login.
Ads (Google AdSense) may appear on reading pages such as the guides and calculators. There are no ads on the editor screen.
Is there a website or program for drawing perfboard layouts?
Patterndo is exactly that: a website for drawing perfboard layouts. Without installing anything, open /editor in your browser and place parts and draw wires and jumpers on the same 2.54 mm grid as a real perfboard.
Unlike a layout drawn on paper, in Excel, or in PowerPoint, it works out the connections (nets) from the wires you draw, so you can check for shorts and polarity mistakes and even simulate whether an LED lights up before you solder. One flip shows the copper side you will solder, mirrored exactly as it will look.
Where is my board saved?
Every time you edit, the editor compresses the current board and updates the ?b= value in the address bar. Bookmark or copy the same address and you can reopen the board exactly as it was.
There are no accounts, so no server keeps the board for you. For boards that matter, make a short link with [Share], or download a JSON file with [More → Export RAW] and keep it yourself. Clearing your browser history may also remove the board stored in the address.
How long do share links last? Who can see them?
A board saved with a share link (an address starting with /s/) is kept for 180 days from the day it was last saved. Saving again to the same link restarts the retention period.
Anyone who knows the link address can view it, and it is set not to appear in search engines. Do not put personal information in part labels or net aliases. If you need permanent storage, download the RAW JSON file.
Draw your first board now
The editor opens instantly with no install. If anything is unclear, keep a guide open next to it and follow along.
Simulation results are reference material for learning and pre-checks. They use ideal part models and do not guarantee real-circuit behavior or safety; see the Terms of Service for details.