ASCII 127
Delete (DEL)
Control character
Delete. Historically deleted the character under the cursor on paper terminals. Modern Delete/Backspace are usually mapped elsewhere.
Common uses & context
Decimal 127 (0x7F) is the Delete control character — one of the 33 non-printing codes in the C0 control block (0–31 plus DEL at 127). Control characters were designed to command teletype and terminal hardware rather than to represent visible glyphs, so DEL produces no letter, digit, or symbol on screen. Its8-bit binary form is 01111111 and its octal value is 0177.
Delete. Historically deleted the character under the cursor on paper terminals. Modern Delete/Backspace are usually mapped elsewhere.
BecauseDEL is invisible, it is easiest to work with by its numeric code. In most languages you can produce it with the escape or code-point form shown below, and detect it by comparing a byte against 127 (0x7F). When it turns up unexpectedly in text — pasted from a terminal, a legacy file, or a binary blob — it is usually the cause of "invisible character" bugs that break parsing or comparisons.
All encodings at a glance
| Decimal | 127 |
| Hexadecimal | 0x7F |
| Octal | 0177 |
| Binary | 01111111 |
| HTML numeric entity |  |
| URL encoding | %7F |
| UTF-8 bytes | 0x7F |
Code snippets
JavaScript
String.fromCharCode(127); // "DEL"
127.toString(16); // "7f"Python
chr(127) # control char DEL
ord(chr(127)) # 127
hex(127) # '0x7f'HTML
 <!-- numeric entity (no named entity for this character) -->Programming notes
- ▸Detect it by numeric comparison: byte === 127 (0x7F). It has no printable glyph to match on.
- ▸Control characters below 32 are stripped or rejected by many text validators — check for them when sanitizing user input.
- ▸In a hex dump DEL shows as 7F; in a "cat -v" style view it may appear as a caret sequence.
Frequently asked questions
What character is ASCII code 127?
ASCII code 127 is Delete (DEL), a non-printing control/whitespace character. In hexadecimal it is 0x7F and in binary 01111111. It has no visible glyph — it controls formatting or hardware instead of drawing a symbol.
What is 0x7F in ASCII?
Hexadecimal 0x7F equals decimal 127, which is theDelete control character (DEL). To convert hex to ASCII yourself, read the two hex digits as a base-16 number (0x7F = 127) and look up that code point.
How do I write the character with code 127 in code?
In JavaScript use String.fromCharCode(127); in Python use chr(127); in HTML use the numeric entity . In a URL it is percent-encoded as %7F, and in UTF-8 it is stored as the byte sequence 0x7F.
Is ASCII 127 (DEL) printable?
No. DEL (code 127) is a control character with no visible glyph. It instructs software or hardware rather than displaying a symbol, which is why it often appears as an invisible or replacement character when it leaks into ordinary text.