Should I use ~, ≈ or ˜ for approximately?

Use ~ (0x7E) or simply write about in everyday text, and ≈ in math for approximately equal. ˜ is an accent mark with no meaning of its own, so it's the one to avoid: a search for ~5 won't find ˜5, and a script parsing the value won't recognize it either.

Why does Alt+0152 give ˜ instead of ÿ?

The zero sends Windows to the Windows-1252 table, where 152 is the small tilde ˜, a spacing accent rather than a letter. Alt+152 without the zero reads the DOS table and gives ÿ, and on the Windows side ÿ sits at Alt+0255. The capital Ÿ has no DOS code at all, so Alt+0159 is the only Alt code for it.

ASCII 152

Small tildeLowercase y with umlaut

ASCII 152 is ˜ on Windows and ÿ in old DOS.

˜ (Small Tilde) is byte 152 in Windows-1252, Unicode U+02DC. It's a spacing accent, raised and smaller than the ASCII tilde ~ (0x7E). The trap is the HTML entity: &tilde; produces this character, not ~. A page that writes ~/.bashrc or a /~user URL with &tilde; looks fine, but the copied path or link fails, because shells and servers only recognize 0x7E. For a real tilde in HTML, type ~ directly. Its circumflex counterpart ˆ is byte 136. In UTF-8 it's CB 9C, garbled as Ëœ.

ÿ (Small Y with Diaeresis) is byte 152 in code page 437, the original IBM PC character set, and maps to Unicode U+00FF. Windows-1252 has the small tilde ˜ at 152, so DOS text read as Windows-1252 turns L'Haÿ-les-Roses into L'Ha˜-les-Roses. Code page 850 kept ÿ at 152 too. Neither DOS code page has a capital Ÿ.

SymbolLatin Letter

Technical Details

Code Example

</>

#include <stdio.h>

int main(void) {
    /* On Windows (code page 1252) byte 152 is ˜.
       Modern terminals expect UTF-8, so print the code point, not the byte. */
    printf("\u02DC\n");   /* UTF-8: CB 9C */

    unsigned char b = 152;         /* the raw Windows-1252 byte */
    printf("%d 0x%02X\n", b, b);    /* 152 0x98 */
    return 0;
}

Code Example

</>

#include <stdio.h>

int main(void) {
    /* Byte 152 is ÿ only on a console using code page 437
       (chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the
       lone byte 0x98 is invalid and prints as garbage, often �. */
    putchar(152);

    /* char is signed on x86, so a plain char holding 0x98 is -104.
       Use unsigned char when you compare or index by byte value. */
    char c = (char)152;
    unsigned char u = 152;
    printf("\n%d %d\n", c, u);   /* -104 152 */

    /* Portable: print the Unicode character as UTF-8 instead. */
    printf("\u00FF\n");          /* C3 BF */
    return 0;
}

How to Type It

Windows: Hold Alt and type 0152 on the numeric keypad, with Num Lock on. The leading zero picks the Windows code page. No numeric keypad? In Word, type 02DC and press Alt+X.
Mac: Press Option+Shift+N.
Linux: In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type 2dc, then Space.
Phone: The ~ key types a similar but different character. Tap the character at the top of this page to copy it.

How to Type It

Windows: Hold Alt and type 152 on the numeric keypad, with no leading zero. Windows reads it as a DOS code and inserts ÿ.

ÿ is also ASCII 255 on Windows, which has the full guide.

Frequently Asked Questions

Use ~ (0x7E) or simply write about in everyday text, and ≈ in math for approximately equal. ˜ is an accent mark with no meaning of its own, so it's the one to avoid: a search for ~5 won't find ˜5, and a script parsing the value won't recognize it either.
The zero sends Windows to the Windows-1252 table, where 152 is the small tilde ˜, a spacing accent rather than a letter. Alt+152 without the zero reads the DOS table and gives ÿ, and on the Windows side ÿ sits at Alt+0255. The capital Ÿ has no DOS code at all, so Alt+0159 is the only Alt code for it.

Frequently Asked Questions

The zero sends Windows to the Windows-1252 table, where 152 is the small tilde ˜, a spacing accent rather than a letter. Alt+152 without the zero reads the DOS table and gives ÿ, and on the Windows side ÿ sits at Alt+0255. The capital Ÿ has no DOS code at all, so Alt+0159 is the only Alt code for it.

ASCII 152

Small tildeLowercase y with umlaut

ASCII 152 is ˜ on Windows and ÿ in old DOS.

Symbol

Latin Letter

#include <stdio.h>

int main(void) {

/* On Windows (code page 1252) byte 152 is ˜.

Modern terminals expect UTF-8, so print the code point, not the byte. */

printf("\u02DC\n"); /* UTF-8: CB 9C */

unsigned char b = 152; /* the raw Windows-1252 byte */

printf("%d 0x%02X\n", b, b); /* 152 0x98 */

return 0;

}

#include <stdio.h>

int main(void) {

/* Byte 152 is ÿ only on a console using code page 437

(chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the

lone byte 0x98 is invalid and prints as garbage, often �. */

putchar(152);

/* char is signed on x86, so a plain char holding 0x98 is -104.

Use unsigned char when you compare or index by byte value. */

char c = (char)152;

unsigned char u = 152;

printf("\n%d %d\n", c, u); /* -104 152 */

/* Portable: print the Unicode character as UTF-8 instead. */

printf("\u00FF\n"); /* C3 BF */

return 0;

}