About

ASCII (American Standard Code for Information Interchange) maps each character to a unique integer in the range 0 - 127. Extended ASCII expands this to 255, covering additional Latin, box-drawing, and accented characters. Misinterpreting a single code - substituting 32 (space) for 23 (End of Transmission Block) - can corrupt serial protocols, break file headers, or produce garbled output in embedded systems. This tool parses a sequence of decimal ASCII values separated by a chosen delimiter, validates each against the range 0 - 255, and maps them via String.fromCharCode(n) to produce the corresponding text. The reverse mode encodes each character of an input string back to its decimal code using charCodeAt(i).

Control characters (codes 0 - 31 and 127) are non-printable. This tool renders them as labeled placeholders so you can identify NULL (0), TAB (9), LF (10), CR (13), and ESC (27) without ambiguity. Note: this converter handles single-byte encodings only. Multi-byte encodings like UTF-8 require separate tooling for codepoints above 255.

Formulas

The conversion from an ASCII decimal code to a character uses a direct mapping function defined by the ASCII standard (ANSI X3.4-1986).

char = fromCharCode(n), where n ∈ [0, 255]

The reverse operation extracts the decimal code from a character at position i in a string:

code = charCodeAt(i), where i ∈ [0, len − 1]

Where n is a decimal integer representing the ASCII code, char is the resulting single character, i is the zero-based index within the input string, and len is the total string length. Control characters (n < 32 or n = 127) are non-printable and are rendered with their standard abbreviations (NUL, SOH, STX, etc.).

Delimiter auto-detection scans the input and counts occurrences of common separators: comma (44), space (32), semicolon (59), tab (9), and newline (10). The separator with the highest frequency is selected as the active delimiter.

Reference Data

Dec	Hex	Char	Description
0	00	NUL	Null character
7	07	BEL	Bell / Alert
8	08	BS	Backspace
9	09	TAB	Horizontal Tab
10	0A	LF	Line Feed (newline)
13	0D	CR	Carriage Return
27	1B	ESC	Escape
32	20	SP	Space
48 - 57	30-39	0-9	Digits
65 - 90	41-5A	A - Z	Uppercase Latin letters
97 - 122	61-7A	a - z	Lowercase Latin letters
33	21	!	Exclamation mark
34	22	"	Double quotation mark
35	23	#	Number sign / Hash
36	24	$	Dollar sign
37	25	%	Percent sign
38	26	&	Ampersand
40	28	(	Left parenthesis
41	29	)	Right parenthesis
42	2A	*	Asterisk
43	2B	+	Plus sign
44	2C	,	Comma
45	2D	-	Hyphen-minus
46	2E	.	Full stop / Period
47	2F	/	Solidus / Slash
64	40	@	Commercial at
91	5B	[	Left square bracket
92	5C	\	Reverse solidus / Backslash
93	5D	]	Right square bracket
123	7B	{	Left curly bracket
125	7D	}	Right curly bracket
126	7E	~	Tilde
127	7F	DEL	Delete
128	80	Ç	Latin capital C with cedilla (Extended)
176	B0	°	Degree sign (Extended)
181	B5	µ	Micro sign (Extended)
224	E0	α	Greek lowercase alpha (Extended)
227	E3	π	Greek lowercase pi (Extended)
241	F1	±	Plus-minus sign (Extended)
246	F6	÷	Division sign (Extended)
248	F8	°	Degree sign alt (Extended)
255	FF	NBSP	Non-breaking space (Extended)

Frequently Asked Questions

Any token parsed to an integer outside the range 0 - 255 is flagged as invalid. The tool highlights the offending value in the output and skips it during conversion. Standard ASCII covers 0 - 127; extended ASCII covers 128 - 255. Values above 255 fall into Unicode territory and require a different encoding scheme (UTF-8 or UTF-16).

The converter scans your input and counts occurrences of five common delimiters: comma, space, semicolon, tab, and newline. The delimiter with the highest count is automatically selected. If counts are tied, the priority order is comma, space, semicolon, tab, newline. You can always override auto-detection by manually selecting a delimiter from the dropdown.

Codes 0 - 31 and 127 are control characters defined by the ASCII standard. They were designed for device control (carriage return, line feed, escape sequences), not visual display. This tool renders them as labeled tags (e.g., [NUL], [TAB], [LF]) so you can identify them. Code 32 is the standard space character, which appears blank but is valid printable output.

Yes. Switch to the Text → ASCII mode using the direction toggle. Enter any text string and the tool will output the decimal ASCII code for each character, separated by your chosen delimiter. Characters outside the extended ASCII range (0 - 255) will show their Unicode codepoint value instead, with a warning indicator.

Standard ASCII (ANSI X3.4-1986) defines 128 characters using 7 bits: codes 0 - 127. This covers English letters, digits, punctuation, and control characters. Extended ASCII uses the full 8-bit byte, adding codes 128 - 255 for accented characters, box-drawing symbols, and mathematical signs. The exact mapping of extended codes varies by code page (CP437, CP1252, ISO 8859-1). This tool uses the browser's native String.fromCharCode mapping.

If your input uses inconsistent delimiters (e.g., some commas and some spaces), set the delimiter to Auto-Detect. The tool will pick the most frequent separator. For best results, normalize your input to a single delimiter before conversion. The tool also strips leading and trailing whitespace from each token, so minor spacing inconsistencies around commas or semicolons are tolerated.