Source: https://mokxi.com/logic-gate-simulator
Updated: 2026-09-27

Simulator

# Logic gates, as real chips on a breadboard

Mokxi is a free logic gate simulator that runs in your browser, with nothing to install and no account needed. Most browser logic simulators draw an ideal symbol and stop there. Mokxi has ideal gates too, and it also has the 74HC00, 04, 08, 32, 74 and 86 as real DIP chips with supply pins, supply-relative thresholds and a propagation delay you could measure with a scope.

Sign up free or see every part

- 192 parts on the bench
- 25 boards running now
- 1.00x real time, on every board

Hold the button

A NAND and an XOR, both real chips. Hold either button, or click anything else to open it in the editor.

## Ideal gates and real chips, on the same bench

One teaches the truth table. The other teaches the part.

The plain "Logic gate" and "Inverter" parts are ideal: two inputs, one output, no supply pins, a 10 nanosecond inertial delay so a pulse narrower than that never reaches the output at all. They are the right part for teaching the truth table before the chip.

The 74HC00, 74HC04, 74HC08, 74HC32, 74HC74 and 74HC86 are the real 14-pin DIP packages: four or six gates in one body, a VCC and a GND pin that actually have to be wired, and every output going high-impedance the moment the chip is unpowered. That last part is the single most common reason a beginner’s logic circuit does nothing at all, and Mokxi models it rather than hiding it.

## What the running circuit above shows

Two buttons, a real NAND and a real XOR, four rows of a truth table you can press instead of read.

A, B

74HC00 (NAND)

74HC86 (XOR)

0, 0

1

0

1, 0

1

1

0, 1

1

1

1, 1

0

0

Two 10 kilohm pull-downs hold each input at 0 V while its button is not held, because a CMOS input left floating is not a zero, it is whatever charge happened to be on it last. Every gate on both chips carries the datasheet’s typical propagation delay of 9 nanoseconds from an input edge to the output moving.

## The chips on the bench

Every logic part Mokxi has today.

Logic gate An ideal AND, OR, NAND, NOR or XOR, for teaching the idea before the chip. Inverter An ideal inverter, for the same job. 74HC00 quad NAND Four NAND gates in a DIP-14, with supply pins and a real propagation delay. 74HC04 hex inverter Six inverters, same package, same rules. 74HC08 quad AND Four AND gates. 74HC32 quad OR Four OR gates. 74HC74 dual flip-flop Two D flip-flops with preset and clear. Divide a clock with one. 74HC86 quad XOR Four XOR gates.

## Digital electronics, one circuit at a time

Explainers that each end in a circuit built from these chips, running.

Digital electronics on Chromebooks, unit by unit Half adder and full adder Flip-flops: SR latch, D and JK The 555 monostable Moving a class off Multisim Live

## Questions

Is it free?

Yes. Every gate and every 74HC chip, on the free plan, with no card.

What is the difference between the ideal gate and the 74HC chip?

The ideal gate has no supply pins and drives from nowhere, like a symbol in a textbook. The 74HC chip has to be powered, has a real propagation delay from the datasheet, and its outputs go high-impedance when it is not.

Can I build a flip-flop or a counter?

Yes. The 74HC74 is a dual D flip-flop with preset and clear, and the templates gallery has a binary counter built from two of them.

Do I need an account?

No. An account is only for saving a project to the cloud and sharing it by link.

## Press Run on a real chip

Open the editor, drop a part on the breadboard and press Run. Nothing to install, and no account needed.

Start building Open the editor