ASCII Converter
Work with real 7-bit ASCII—not a vague 0–255 “extended ASCII” table. Encode ASCII text, decode mixed numeric notation, inspect control codes and open the complete 0–127 reference when you need the exact value.
You can mix decimal (65), hex (0x41, \x41 or \u0041), 8-bit binary (01000001), prefixed binary (0b01000001), octal (0o101) and ASCII-range code points (U+0041).
“Extended ASCII” Is Not One Character Set
Standard ASCII has exactly 128 values: 0 through 127. The phrase “extended ASCII” is often used for many incompatible 8-bit encodings—Windows-1252, ISO-8859 families, DOS code pages and others. The byte 0x80 therefore has no single universal “extended-ASCII character.”
Values above 127 are rejected on purpose. If you have bytes 128–255, first identify the actual encoding rather than guessing from the number.
Why 65, 0x41 and 01000001 All Mean A
Decimal, hexadecimal, octal and binary are only different ways to write the same integer. ASCII assigns the integer 65 to uppercase A. Nothing changes about the character when that number is written as hexadecimal 0x41, binary 01000001 or octal 0o101.
ASCII itself is a seven-bit code. The binary view pads each value to eight bits because byte-oriented dumps normally show the unused high bit as zero; A is therefore shown as 01000001even though its significant ASCII bits are 1000001.
LF 10 0x0A 00001010 0o012
SPACE 32 0x20 00100000 0o040
Control Codes Explain “Blank” or Broken-Looking Output
ASCII was designed for communication systems, not only visible text. It includes NUL, BEL, backspace, horizontal tab, line feed, carriage return, escape and several historical device-control codes. Decoding 10 should create a line feed—not the visible characters “10.”
Named control-code labels make those invisible values easier to spot. Copying controls into terminals, CSV, logs or source code can change behavior even when the visible text looks blank.
Newline Problems Often Come Down to CR and LF
ASCII assigns CR to 13 and LF to 10. Unix-style text normally uses LF as its line ending, while CRLF is common in Internet protocols and Windows text. Seeing 13 10 in a byte dump is therefore different from seeing only 10.
When debugging protocol headers or copied files, inspect the individual codes rather than assuming every visual line break uses the same bytes.
ASCII Is Embedded Inside Unicode and UTF-8
Unicode preserves the ASCII assignments U+0000 through U+007F, and UTF-8 encodes those code points as the same one-byte values. That is why plain English ASCII text also looks identical in a UTF-8 byte dump.
The similarity ends above 127. A Devanagari letter or emoji is not “large ASCII”; it is a Unicode character whose UTF-8 encoding uses multiple bytes.
When ASCII Is Not the Right Model
Unicode code points
Use a Unicode/escape tool for U+0905, U+1F680 and other non-ASCII characters.
UTF-8 bytes
Use the Binary Encoder Decoder when you need the actual bytes of modern multilingual text.
Unknown 8-bit data
Identify the encoding first when values 128–255 come from a legacy file or protocol.
The historic Internet Standard for 7-bit US-ASCII, including the familiar control abbreviations. RFC 20 also shows the common practice of carrying seven ASCII bits in an eight-bit byte with the high bit set to zero.
Unicode preserves the ASCII-range assignments at U+0000 through U+007F and provides current names and aliases for the control and graphic characters.