ASCII Converter & Code Translator — Text ↔ Decimal/Hex/Binary/Octal

Frequently Asked Questions

What is ASCII?

ASCII (American Standard Code for Information Interchange) is a character encoding standard that assigns a unique numeric value to 128 characters, including letters (A-Z, a-z), digits (0-9), punctuation marks, and control characters. Developed in the early 1960s and standardized in 1968, ASCII was the dominant character encoding for computers and telecommunications for decades. Each character is represented by a 7-bit integer from 0 to 127, though it is typically stored as an 8-bit byte.

How do you convert text to ASCII?

To convert text to ASCII, look up the decimal code for each character in the ASCII table. For example, the letter 'A' has the ASCII code 65, 'B' is 66, and lowercase 'a' is 97. Spaces have ASCII code 32. To express these in hexadecimal, convert each decimal code: 65 in decimal is 41 in hex. In binary, 65 is 01000001. Most programming languages provide built-in functions for this conversion, such as ord() in Python, charCodeAt() in JavaScript, or (int) casting in C.

What is the ASCII code for a space?

The ASCII code for a space character is 32 in decimal (20 in hexadecimal, 00100000 in binary). Space (code 32) is the lowest-numbered printable ASCII character. Codes 0-31 and 127 are control characters used for communication control (like newline, tab, carriage return) rather than printable symbols. Among these, horizontal tab is code 9, line feed (newline) is code 10, and carriage return is code 13.

What is the difference between ASCII and Unicode?

ASCII uses 7 bits to represent 128 characters, covering English letters, digits, and common symbols. Unicode is a much larger standard that encodes over 149,000 characters from virtually all writing systems worldwide, including Chinese, Arabic, emoji, and mathematical notation. ASCII characters occupy exactly the same positions (0-127) in Unicode, so all ASCII text is valid Unicode. Unicode uses UTF-8 as its most common encoding, where ASCII characters are stored in 1 byte while other characters use 2-4 bytes.

What are ASCII control characters?

ASCII control characters are the first 32 codes (0-31) plus code 127 (DEL). They are non-printable characters originally used to control communication devices and terminals. Common examples include: NUL (0) — null terminator used to end strings in C; TAB (9) — horizontal tab; LF (10) — line feed / newline used in Unix systems; CR (13) — carriage return used in old typewriters and Windows line endings (CRLF); ESC (27) — escape character used to start terminal escape sequences; DEL (127) — delete.

What is the difference between uppercase and lowercase in ASCII?

In ASCII, uppercase letters A-Z have codes 65-90, and lowercase letters a-z have codes 97-122. The difference between any uppercase letter and its lowercase counterpart is exactly 32 (for example, A=65 and a=97; B=66 and b=98). In binary, this difference is bit 5 (value 32): uppercase letters have bit 5 set to 0 and lowercase have it set to 1. This elegant design means you can toggle case by flipping a single bit, which makes case conversion extremely efficient in low-level programming.

What is extended ASCII?

Extended ASCII refers to various 8-bit character encodings that use codes 128-255 to add additional characters beyond the original 128 ASCII characters. Unlike the standard ASCII range (0-127), which is universally agreed upon, codes 128-255 vary by encoding. Common extensions include ISO 8859-1 (Latin-1) which adds Western European characters like accented letters (é, ü, ñ), and Windows-1252 which is similar but includes typographic symbols. Extended ASCII is largely superseded by Unicode for modern applications.

How does ASCII relate to UTF-8?

UTF-8 is designed to be backward-compatible with ASCII. For the first 128 code points (0-127), UTF-8 uses exactly the same single byte as ASCII. This means any valid ASCII text is also valid UTF-8 without modification. For characters beyond 127, UTF-8 uses multi-byte sequences of 2 to 4 bytes, with the leading byte indicating the sequence length. This backward compatibility made UTF-8 easy to adopt and is one reason it became the dominant encoding on the internet, representing over 98% of web pages.

How do you convert ASCII codes to text?

To convert ASCII decimal codes back to text, look up each number in the ASCII table and write the corresponding character. For example, the sequence 72, 101, 108, 108, 111 spells 'Hello' (H=72, e=101, l=108, l=108, o=111). For hexadecimal input, convert each hex value to decimal first (or look it up directly). In programming, use chr() in Python, String.fromCharCode() in JavaScript, or cast an integer to char in C/C++ and Java.

What is the ASCII code for a newline?

There are two ASCII control characters related to newlines: Line Feed (LF, code 10) and Carriage Return (CR, code 13). Unix/Linux and macOS use LF alone (\n) to end lines. Windows uses the combination CR+LF (\r\n, codes 13 and 10). Old Mac OS used CR alone. LF originated from the mechanical action of advancing paper one line on a printer, while CR moved the print head back to the start of the line — both were needed on physical terminals.

Do Chinese characters have ASCII codes?

ASCII defines only 128 characters: English letters, digits, symbols, and control characters. Chinese characters such as 汉 are outside the ASCII range. They have Unicode code points and can be stored with encodings such as UTF-8 or UTF-16. If you paste Chinese text into this tool, it shows the character’s Unicode code point (U+XXXX) rather than an ASCII code.

What are non-ASCII characters?

Non-ASCII characters are all characters with code points above 127, including Chinese, Japanese, Arabic, accented European letters such as é, ü, and ñ, emoji, and mathematical symbols. They require a Unicode encoding; UTF-8 represents them with two to four bytes.

Do emojis have ASCII codes?

No. Emoji are Unicode characters and lie outside the ASCII range of 0–127. Their code points cover a wide part of Unicode; the smiling face 😀 sits at U+1F600 (decimal 128512), while other symbols reused as emoji, such as ❤ (U+2764) or ☺ (U+263A), live lower in Unicode. In every case, they belong to Unicode, not ASCII.

What Is ASCII?

ASCII (American Standard Code for Information Interchange) is a character encoding standard that maps 128 characters to numeric values (0–127). It covers the English alphabet (upper and lowercase), digits 0–9, punctuation, and 33 non-printable control characters such as tab, newline, and carriage return.

Developed in the early 1960s and standardized in 1968, ASCII was the dominant encoding for computers and telecommunications for decades, and still forms the foundation of modern encodings such as UTF-8.

How to Use

Text to ASCII

Select the Text to ASCII tab
Type or paste any text into the input field
Choose an Output Format: Decimal, Hexadecimal, Binary, or Octal
The converted codes appear instantly with a character-by-character breakdown
Click the Copy button to copy the result

ASCII to Text

Select the ASCII to Text tab
Enter ASCII codes separated by spaces or commas (e.g., 72 101 108 108 111)
Auto mode checks every format that can decode the complete sequence within 0–127
If several formats produce different text, choose one of the displayed interpretations
Use 0x41, 0o101, or 0b01000001 to state the base explicitly
Click Copy to copy the decoded result

How to Convert 65 to ASCII Character A

The decimal ASCII code for uppercase A is 65. Look up decimal value 65 in the complete table, or enter A in the Text to ASCII tab and choose Decimal.

The conversion is A → 65. The same code is 41 in hexadecimal, 01000001 in binary, and 101 in octal.

ASCII is limited to code points 0–127, so this example is a standard 7-bit ASCII character.

How to Convert 41 Hex to ASCII Character A

Hexadecimal 41 equals decimal 4 × 16 + 1 = 65. Decimal 65 is uppercase A in the ASCII table.

In the ASCII to Text tab, select Hexadecimal and enter 41, or enter 0x41 in Auto mode.

The result is 41₁₆ → 65₁₀ → A. A plain 41 is ambiguous: decimal produces ), hexadecimal produces A, and octal produces !. Auto mode shows all three choices instead of guessing.

How to Convert Binary 01000001 to ASCII

Binary 01000001 represents 64 + 1 = 65 in decimal. ASCII decimal 65 is uppercase A.

Enter 01000001 in the ASCII to Text tab. Auto checks the complete input against decimal, hexadecimal, binary, and octal syntax and the ASCII range. Only binary is valid for this value, so it is selected automatically.

The conversion is 01000001₂ → 65₁₀ → A. Seven-bit values such as 1000001 are also recognized as binary.

Output Formats Explained

Decimal — The standard base-10 representation. Each character maps to a number 0–127. This is the format most ASCII tables use and the most readable for humans (e.g., A=65, space=32).

Hexadecimal — Base-16 representation using digits 0-9 and letters A-F. Commonly used in programming, memory dumps, and URL percent-encoding (e.g., A=41, space=20).

Binary — Base-2 representation using only 0 and 1. Each ASCII character occupies 8 bits (one byte) with the leading bit always 0 for standard ASCII (e.g., A=01000001).

Octal — Base-8 representation, historically used in Unix file permissions and early computing. Each standard ASCII character fits in 3 octal digits (e.g., A=101, space=040).

Complete ASCII Table (0–127)

Control Characters (0–31 and 127)

Decimal	Hex	Binary	Octal	Mnemonic	Description
0	00	00000000	000	NUL	Control character
1	01	00000001	001	SOH	Control character
2	02	00000010	002	STX	Control character
3	03	00000011	003	ETX	Control character
4	04	00000100	004	EOT	Control character
5	05	00000101	005	ENQ	Control character
6	06	00000110	006	ACK	Control character
7	07	00000111	007	BEL	Control character
8	08	00001000	010	BS	Control character
9	09	00001001	011	HT	Control character
10	0A	00001010	012	LF	Control character
11	0B	00001011	013	VT	Control character
12	0C	00001100	014	FF	Control character
13	0D	00001101	015	CR	Control character
14	0E	00001110	016	SO	Control character
15	0F	00001111	017	SI	Control character
16	10	00010000	020	DLE	Control character
17	11	00010001	021	DC1	Control character
18	12	00010010	022	DC2	Control character
19	13	00010011	023	DC3	Control character
20	14	00010100	024	DC4	Control character
21	15	00010101	025	NAK	Control character
22	16	00010110	026	SYN	Control character
23	17	00010111	027	ETB	Control character
24	18	00011000	030	CAN	Control character
25	19	00011001	031	EM	Control character
26	1A	00011010	032	SUB	Control character
27	1B	00011011	033	ESC	Control character
28	1C	00011100	034	FS	Control character
29	1D	00011101	035	GS	Control character
30	1E	00011110	036	RS	Control character
31	1F	00011111	037	US	Control character
127	7F	01111111	177	DEL	Control character

Printable Characters (32–126)

Decimal	Hex	Binary	Octal	Character	Description
32	20	00100000	040	Space	Printable character
33	21	00100001	041	!	Printable character
34	22	00100010	042	"	Printable character
35	23	00100011	043	#	Printable character
36	24	00100100	044	$	Printable character
37	25	00100101	045	%	Printable character
38	26	00100110	046	&	Printable character
39	27	00100111	047	'	Printable character
40	28	00101000	050	(	Printable character
41	29	00101001	051	)	Printable character
42	2A	00101010	052	*	Printable character
43	2B	00101011	053	+	Printable character
44	2C	00101100	054	,	Printable character
45	2D	00101101	055	-	Printable character
46	2E	00101110	056	.	Printable character
47	2F	00101111	057	/	Printable character
48	30	00110000	060	0	Printable character
49	31	00110001	061	1	Printable character
50	32	00110010	062	2	Printable character
51	33	00110011	063	3	Printable character
52	34	00110100	064	4	Printable character
53	35	00110101	065	5	Printable character
54	36	00110110	066	6	Printable character
55	37	00110111	067	7	Printable character
56	38	00111000	070	8	Printable character
57	39	00111001	071	9	Printable character
58	3A	00111010	072	:	Printable character
59	3B	00111011	073	;	Printable character
60	3C	00111100	074	<	Printable character
61	3D	00111101	075	=	Printable character
62	3E	00111110	076	>	Printable character
63	3F	00111111	077	?	Printable character
64	40	01000000	100	@	Printable character
65	41	01000001	101	A	Printable character
66	42	01000010	102	B	Printable character
67	43	01000011	103	C	Printable character
68	44	01000100	104	D	Printable character
69	45	01000101	105	E	Printable character
70	46	01000110	106	F	Printable character
71	47	01000111	107	G	Printable character
72	48	01001000	110	H	Printable character
73	49	01001001	111	I	Printable character
74	4A	01001010	112	J	Printable character
75	4B	01001011	113	K	Printable character
76	4C	01001100	114	L	Printable character
77	4D	01001101	115	M	Printable character
78	4E	01001110	116	N	Printable character
79	4F	01001111	117	O	Printable character
80	50	01010000	120	P	Printable character
81	51	01010001	121	Q	Printable character
82	52	01010010	122	R	Printable character
83	53	01010011	123	S	Printable character
84	54	01010100	124	T	Printable character
85	55	01010101	125	U	Printable character
86	56	01010110	126	V	Printable character
87	57	01010111	127	W	Printable character
88	58	01011000	130	X	Printable character
89	59	01011001	131	Y	Printable character
90	5A	01011010	132	Z	Printable character
91	5B	01011011	133	[	Printable character
92	5C	01011100	134	\	Printable character
93	5D	01011101	135	]	Printable character
94	5E	01011110	136	^	Printable character
95	5F	01011111	137	_	Printable character
96	60	01100000	140	`	Printable character
97	61	01100001	141	a	Printable character
98	62	01100010	142	b	Printable character
99	63	01100011	143	c	Printable character
100	64	01100100	144	d	Printable character
101	65	01100101	145	e	Printable character
102	66	01100110	146	f	Printable character
103	67	01100111	147	g	Printable character
104	68	01101000	150	h	Printable character
105	69	01101001	151	i	Printable character
106	6A	01101010	152	j	Printable character
107	6B	01101011	153	k	Printable character
108	6C	01101100	154	l	Printable character
109	6D	01101101	155	m	Printable character
110	6E	01101110	156	n	Printable character
111	6F	01101111	157	o	Printable character
112	70	01110000	160	p	Printable character
113	71	01110001	161	q	Printable character
114	72	01110010	162	r	Printable character
115	73	01110011	163	s	Printable character
116	74	01110100	164	t	Printable character
117	75	01110101	165	u	Printable character
118	76	01110110	166	v	Printable character
119	77	01110111	167	w	Printable character
120	78	01111000	170	x	Printable character
121	79	01111001	171	y	Printable character
122	7A	01111010	172	z	Printable character
123	7B	01111011	173	{	Printable character
124	7C	01111100	174	\|	Printable character
125	7D	01111101	175	}	Printable character
126	7E	01111110	176	~	Printable character

ASCII vs. Unicode

ASCII defines only 128 characters and covers English text. Unicode extends this to over 149,000 characters from virtually every writing system worldwide.

UTF-8, the most common Unicode encoding, is designed to be fully backward-compatible with ASCII: the first 128 UTF-8 code points are identical to ASCII, stored as single bytes. Characters outside the ASCII range use 2–4 bytes in UTF-8.

This means:

Any ASCII file is also valid UTF-8 without any conversion
ASCII tools work correctly on the ASCII portion of any UTF-8 text
Non-ASCII characters (e.g., accented letters, CJK, emoji) require Unicode

Common Use Cases

Debugging — Inspect the exact byte values of a string when troubleshooting encoding issues or protocol implementations
Network protocols — HTTP, SMTP, and many other protocols communicate via ASCII text; understanding ASCII codes helps when reading raw protocol data
Programming — Convert between characters and their numeric codes when working with character arithmetic (e.g., checking if a character is a digit or letter)
Data formats — Understand percent-encoding in URLs (e.g., space = %20) and escape sequences in JSON and CSV
Education — Learn how computers represent text at the byte level

Tips

The difference between any uppercase letter and its lowercase equivalent in ASCII is exactly 32 — flipping bit 5 toggles the case
Digits 0–9 have ASCII codes 48–57, so subtracting 48 from the ASCII code gives the numeric value of the digit
ASCII control characters NUL (0), LF (10), CR (13), and TAB (9) appear frequently in file formats and network protocols — knowing their codes avoids confusion when reading hex dumps