ASCII 15
ASCII 15 is Shift In — the control character SI.
Every representation
| Character | SI (not printable) |
| Name | Shift In |
| Decimal | 15 |
| Hexadecimal | 0x0F |
| Octal | 0017 |
| Binary | 00001111 |
| HTML entity |  |
| Escape sequence | \x0F |
| Unicode | U+000F |
| Keyboard | Ctrl+O |
| Group | Control character |
What it is for
Switched back to the standard character set.
Where the number comes from
Codes 0 to 31 were reserved for control: instructions to a teleprinter rather than characters to print. Code 15 is Ctrl+O because the Ctrl key was originally wired to clear the top two bits of whatever you typed, mapping the letter O at 79 down to 15.
Frequently asked questions
What is ASCII 15?
Shift In (SI), a control character. In hexadecimal it is 0x0F, in octal 0017, and in binary 00001111.
How do I type ASCII 15?
Press Ctrl+O in a terminal. In a string literal you can write it as \\x0F in most languages.
Is ASCII 15 printable?
No. Codes 0 to 31 and 127 are control characters — they were instructions to a teleprinter rather than marks on paper, and most terminals show nothing for them.
Nearby codes
- ASCII 8 — BS
- ASCII 9 — HT
- ASCII 10 — LF
- ASCII 11 — VT
- ASCII 12 — FF
- ASCII 13 — CR
- ASCII 14 — SO
- ASCII 16 — DLE
- ASCII 17 — DC1
- ASCII 18 — DC2
- ASCII 19 — DC3
- ASCII 20 — DC4
- ASCII 21 — NAK
- ASCII 22 — SYN
Full ASCII table · Text to binary converter · Number base converter