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ASCII to Binary

Convert ASCII codes to binary — decimal character codes as 8-bit bytes.

100% Free No signup Privacy-friendly Binary & Number Tools
Updated Sep 2026

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How to use ASCII to Binary

  1. Enter decimal ASCII codes separated by spaces — e.g. 72 105 (H and i).
  2. Read the binary instantly: 72 105 → 1001000 1101001.
  3. Pad mentally to 8 bits where byte alignment matters — 1001000 is the byte 01001000.
  4. Click “Copy result” to take the bit patterns into your worksheet or notes.

What is ASCII to Binary?

An ASCII to binary converter takes decimal character codes — like 72 for H — and rewrites each as binary: 72 becomes 1001000 (01001000 as a padded byte). It bridges the two ways of writing the same character data: the human-friendly decimal code and the bit pattern actually stored in memory.

It is essentially a decimal-to-binary conversion applied per code, and it completes the encoding chain taught in every computing course: character → ASCII code → binary byte. A is 65 is 01000001 — three notations, one letter.

About the ASCII to Binary

Paste one or more decimal ASCII codes separated by spaces and each converts to binary instantly: 72 105 → 1001000 1101001.

Students use it for the code-to-bits half of encoding exercises; teachers use it to build worksheets where the decimal codes are given and the bit patterns are the answer; developers use it to visualize which bits a given character sets — useful when a protocol or file format tests individual bits of a byte. Non-numeric tokens are flagged by name rather than skipped.

Conversion is exact and runs in your browser. Binary to ASCII reverses it; if you're starting from the text itself rather than the codes, Text to Binary does both steps in one go.

Frequently Asked Questions

1001000 — padded to a byte, 01001000. That's the letter H: 64 + 8 = 72.
Leading zeros don't change a number's value, so 72 converts to 1001000. When you need byte notation, pad to 8 digits: 01001000 — same value, storage-friendly form.
The input: this tool starts from the numeric codes (72 105), Text to Binary starts from the characters themselves (Hi). Same output, one step apart in the encoding chain.
Bit 5 (value 32): A is 01000001 and a is 01100001. Uppercase and lowercase codes differ by exactly that one bit across the whole alphabet.
Yes — any non-negative number converts; codes above 127 just produce more than 8 bits (233 → 11101001). Those are Unicode code points beyond classic ASCII.

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