Binary to ASCII Code Converter

charcode
2⁷2⁶2⁵2⁴2³2²2¹2⁰
A
65
01000001

Show the working for ASCII → binary

This converter works on code values, one at a time, from the table. Codes run from 0 to 127; anything above that is reported as out of range. For whole text rather than single codes, use Binary to Text; for a plain number, use Binary to Decimal.

Going the other way? Convert ASCII code back to binary →

How do you convert binary to ASCII?

Binary to ASCII code conversion reads each 8-bit group as a number from 0 to 127, the ASCII code, which names one row of the ASCII table.

In short

01000001 is ASCII code 65, the letter A. Convert each 8-bit group to decimal (64 + 1 = 65) and look that value up in the ASCII table; values above 127 fall outside ASCII.

  1. Read the first 8-bit group: 01000001.
  2. Convert it to decimal: 01000001 is 65.
  3. Check the code in the table: 65 is the letter A, inside 0–127, so the ASCII code is 65.
  4. Repeat for every group: 01000001 = 65.

Binary to ASCII returns the code value, 65, not the letter A; the binary, text and ASCII converters show which one returns letters instead.

Binary to ASCII Code Conversion Table

The codes this page works through, each with the character it stands for and the same value in hex, octal and binary. Find the code in the first column and read across; the row is the whole conversion. Codes 0 to 31 and 127 have no glyph, so the Char column shows their short name instead. This page shows the rows you need; ASCII code chart (decimal, hex, octal, binary) carries all 128.

Binary to ASCII Code Conversion Table
DecCharHexOctBin
10LF0A01200001010
13CR0D01500001101
32(space)2004000100000
33!2104100100001
4803006000110000
5793907100111001
65A4110101000001
72H4811001001000
90Z5A13201011010
97a6114101100001
122z7A17201111010

The base this page writes, defined by the digits it uses, how a value is marked, and what each position is worth.

Base reference
BaseRadixDigits PrefixPlace worthTypical range
Binary20, 1 0b2ⁿ8-bit byte 0–255 (00000000–11111111); 4-bit nibble 0–15; 16/32/64-bit words

Worked Example: 01000001 to ASCII Code

One code value, taken from the table and written out in full. This is the same working the converter shows when you turn on "show steps".

charcode
2⁷2⁶2⁵2⁴2³2²2¹2⁰
A
65
01000001

Result: 01000001 = 65

Start with the group, 01000001. Its place values add up to 64 + 1 = 65, and row 65 of the table is the letter A, so the ASCII code is 65.

A group above 01111111, which is 127, has no row: the converter reports it as out of range instead of guessing. A group of only seven digits is read with its leading zero restored, and the note under the boxes says so.

Check it in reverse

Read it back and you arrive where you started: the letter A is code 65, which is 01000001 in binary. The table is a two-way lookup, not a calculation, so no rounding or padding can change the answer. To verify the result by hand, write those ASCII codes back in 8 bits and compare it with the value you started from.

Worked examples: binary to ASCII code

Each example gives the value first, then the working. Click a value to load it in the converter.

What is 0b01000001 in ASCII code?

0b01000001 is 65 in ASCII code.

Method: 01000001 is 65 in decimal, and code 65 is the character A.

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What is 0b1000001 in ASCII code?

0b1000001 is 65 in ASCII code.

Method: 01000001 is 65 in decimal, and code 65 is the character A.

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What is 0b1100001 in ASCII code?

0b1100001 is 97 in ASCII code.

Method: 01100001 is 97 in decimal, and code 97 is the character a.

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What is 0b1001000 in ASCII code?

0b1001000 is 72 in ASCII code.

Method: 01001000 is 72 in decimal, and code 72 is the character H.

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What is 0b100000 in ASCII code?

0b100000 is 32 in ASCII code.

Method: 00100000 is 32 in decimal, and code 32 is the character (space).

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What is 0b110000 in ASCII code?

0b110000 is 48 in ASCII code.

Method: 00110000 is 48 in decimal, and code 48 is the character 0.

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What is 0b100001 in ASCII code?

0b100001 is 33 in ASCII code.

Method: 00100001 is 33 in decimal, and code 33 is the character !.

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What is 0b1011010 in ASCII code?

0b1011010 is 90 in ASCII code.

Method: 01011010 is 90 in decimal, and code 90 is the character Z.

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What is 0b1111010 in ASCII code?

0b1111010 is 122 in ASCII code.

Method: 01111010 is 122 in decimal, and code 122 is the character z.

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What is 0b111001 in ASCII code?

0b111001 is 57 in ASCII code.

Method: 00111001 is 57 in decimal, and code 57 is the character 9.

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What is 0b1010 in ASCII code?

0b1010 is 10 in ASCII code.

Method: 00001010 is 10 in decimal, and code 10 is the control code LF.

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What is 0b1101 in ASCII code?

0b1101 is 13 in ASCII code.

Method: 00001101 is 13 in decimal, and code 13 is the control code CR.

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Every example above reverses exactly — write the same codes back as 8-bit values.

What Changes the Code Output?

Values above 127

A value above 127 is out of range and the converter says so rather than guessing. Codes 128–255 belong to extended sets such as Latin-1, not to ASCII, so there is no single right character for them. Every code that is in range is listed in the complete ASCII table.

Which base the code is written in

The same code can be typed as decimal, hex, octal or binary, and the base selector says which one you mean. 65, 41, 101 and 01000001 are all the letter A. Pick the wrong base and you look up a different row.

Control codes and printable codes

Codes 32 to 126 are printable characters; 0–31 and 127 are control codes. A control code has no glyph, so the table shows its short name instead — 10 is LF, 13 is CR. Converting one is valid; displaying one is not.

One code or a list

Several codes separated by spaces, commas or new lines convert as a list, in order, and each keeps its own row. The separator is a display choice and does not change any value. A run with no separator is cut into 8-digit codes.

Binary to ASCII Code in Code

The same rule in one line. Both read the binary codes and return their decimal values.

Python: ' '.join(str(int(g, 2)) for g in s.split())
JavaScript: s.split(/\s+/).map(g => parseInt(g, 2)).join(' ')

Common Mistakes

  • Typing text where a code value belongs. The converter reads 72 as one code, not as the characters 7 and 2 — for whole text use the binary to text translator.
  • Reading a code in the wrong base. 41 is A in hex and ) in decimal.
  • Expecting a character above 127. That value is outside ASCII and the answer depends on which extended set is meant.
  • Dropping the padding on a fixed-width code, so a list of codes can no longer be split apart.

Frequently Asked Questions

Why does binary to ASCII give a number and binary to text give a letter?

Because they stop at different points. This page reads 01000001 and gives the ASCII code 65; the text page carries on and shows the character that code stands for. Same table, one step apart — see how binary represents letters and numbers.

How many binary digits does one ASCII code use?

Seven, padded to eight. ASCII defines 128 characters, codes 0–127, using 7 bits; in practice each code is stored in one 8-bit byte with a leading 0. Codes 128–255 are not part of ASCII. They belong to extended sets such as Latin-1 (ISO 8859-1), where 255 is ÿ.

How do you convert binary to ASCII in Python?

Read each 8-digit group with int(g, 2): int('01000001', 2) gives 65. The code section on this page has the one-liner for a whole list. One caveat: 11111111 is 255 as an unsigned 8-bit number (0xFF, 0o377). Read as 8-bit two's complement it is −1; the 8-bit signed range is −128 to 127.

Every code here reads back the same way: the same value converts straight back in the ASCII code to binary direction.

The rest of the family sits on the rest of the binary converters.