What does AND actually compute?

For each bit position, AND produces a 1 only when both input bits are 1; if either bit is 0, the result bit is 0. It's the standard logical/bitwise AND, applied independently across every bit position.

What happens if my two values have different lengths?

The shorter value is left-padded with leading zero digits until it matches the longer value's digit count, then AND runs across every aligned bit position of that shared width.

Why is 1010 AND 0110 equal to 0010?

Comparing bit by bit: 1&0=0, 0&1=0, 1&1=1, 0&0=0, reading left to right. Only the third bit position has a 1 in both operands, so the result is 0010.

How is AND different from OR and XOR?

AND requires both bits to be 1 to produce a 1, making it useful for masking off unwanted bits (clearing everything except a chosen set). OR requires only one bit to be 1, and XOR requires the bits to differ; all three combine the same inputs very differently.

Binary AND Calculator - Bitwise AND of Two Binary Values

Overview

Introduction

Bitwise AND is one of the most common operations in low-level programming, used constantly to mask off or test specific bits within a binary-encoded value.

This tool computes the bitwise AND of two binary values, so you can see exactly which bit positions are 1 in both inputs.

What Is Binary AND Calculator?

A calculator for the bitwise AND of two binary values: it compares the two values bit by bit and keeps a 1 only where both operands have a 1 at that position.

Like the other two-operand binary gate calculators in this category, it automatically left-pads the shorter operand with zero digits so both values line up bit-for-bit before combining them.

How Binary AND Calculator Works

Both Value A and Value B are validated as binary strings, then the shorter is left-padded with leading zero digits to match the longer value's digit count.

The padded values are combined bit-by-bit with AND using BigInt (not JavaScript's native 32-bit-limited bitwise operators), and the result is formatted as a binary string padded to that same shared width.

When To Use Binary AND Calculator

Use it to mask a binary value against a bitmask, keeping only the bits that are set in both, for example testing which flag bits are active in a status register.

It's also a useful teaching tool for showing how AND behaves on real multi-bit binary data rather than single bits.

Often used alongside Binary OR Calculator, Binary NAND Calculator and Binary XOR Calculator.

Features

Advantages

Automatically handles operands of different lengths by zero-padding, so you don't have to align widths by hand first.
Works on arbitrarily long binary values via BigInt, not limited to a fixed 8/16/32/64-bit width.
Instant, deterministic, fully client-side.

Limitations

Zero-padding the shorter operand assumes you want it treated as a smaller number within a larger field; pad manually first if your context expects different alignment.
Only combines two operands at a time; chain the tool manually if you need to AND together more than two values.

Examples

AND of two mixed bit patterns

Input

A: 1010, B: 0110

Output

1010 AND 0110 = 0010, a 1 only where both inputs had a 1 (the third bit position).

Different-width operands get zero-padded

Input

A: 101, B: 1100

Output

A (101) is left-padded to 0101 to match B's 4-bit width, then 0101 AND 1100 = 0100.

Best Practices & Notes

Best Practices

Confirm both values are the width you intend before relying on the auto-padding, since a short operand gets left-padded with zeros.
Use an all-1s mask (like 11111111 for 8 bits) when you want to pass a value through unchanged while confirming the AND logic is wired correctly.

Developer Notes

Implemented with JavaScript BigInt: after zero-padding both operands to the same digit width, it computes `a & b` directly (no complement step), avoiding JavaScript's native 32-bit-limited bitwise operators for operands wider than 32 bits.

Binary AND Calculator Use Cases

Masking a status register or byte to isolate specific flag bits
Teaching or demonstrating the AND logic gate using concrete multi-bit binary examples
Cross-checking a manually-computed AND result

Common Mistakes

Expecting AND to set bits rather than clear them; it can only keep bits that were already 1 in both inputs, never turn a 0 into a 1.
Forgetting that a short operand gets zero-padded on the left, which can change the intended meaning if it was meant to be right-aligned instead.

Tips

Try masking a value against all 1s (like 11111111) to confirm the pass-through behavior of an all-1s mask.
Compare the result with the Binary OR Calculator on the same inputs to see how AND and OR diverge on mixed bit patterns.

Binary AND Calculator