Calculate Binary Addition

Binary addition follows the same column-by-column rules as decimal addition, but with only two digits. 0+0=0, 0+1=1, 1+0=1, and 1+1=10 (0 with a carry of 1). This calculator handles carries automatically across any number of bits.

Yes. All processing happens entirely in your browser using client-side JavaScript. Your binary numbers are never uploaded to any server, so your data stays private on your device.

No. This tool runs 100% client-side. Nothing you enter is saved, logged, or transmitted anywhere. Close the tab and everything is gone.

Completely free, no sign-up needed, no usage limits. Use it as many times as you want for homework, projects, or work.

There is no hard limit. You can add two numbers or hundreds. The tool uses JavaScript BigInt for arbitrary precision, so even very large binary values are handled correctly.

The calculator checks every line for non-binary characters. If a line contains anything other than 0 and 1, you will see a clear error message telling you which line has the problem.

Yes. Shorter numbers are automatically zero-padded on the left to match the longest input, just like adding numbers of different digit counts in decimal.

All modern browsers including Chrome, Firefox, Safari, and Edge. The tool requires BigInt support, which is available in all browsers released after 2020.

Once the page has loaded, it works without an internet connection. All the code runs locally in your browser.

It means the result has more bits than the widest input. For example, adding 1111 (4-bit) + 0001 (4-bit) gives 10000 (5-bit). The extra bit is a carry overflow, which matters in fixed-width hardware but not here since precision is unlimited.