Uppercase O (O) is the Basic Latin character at Unicode U+004F (LATIN CAPITAL LETTER O). It is a core ASCII letter of the Latin alphabet. You can type O directly in HTML, or write a numeric character reference when you need an explicit entity form.
Remember
Character O
Unicode U+004F
Hex entity O
Decimal O
CSS escape \4F
Named entity (none)
Not the same Ó · Ο · 0
Prefer typing O in normal page text. Use O / O for CSS content, generated markup, or when encoding must be explicit.
One line:U+004F → type O / O / O / CSS \4F.
Frequently Asked Questions
Type O directly, or use O (hex), O (decimal), or the CSS escape \4F in content. There is no named HTML entity for U+004F.
U+004F (LATIN CAPITAL LETTER O). Hex 4F, decimal 79. It belongs to Basic Latin (ASCII).
No. Plain ASCII letters do not have named HTML entities. Use numeric references like O or O when you need an entity form.
Prefer typing O in normal page text. Use entities for CSS content, generated markup, or when encoding must be explicit.
HTML entities (O or O) go in markup. The CSS escape \4F goes in stylesheet strings (usually content on ::before/::after).
No. O is Latin capital O (U+004F). Ó is O with acute (Ó, U+00D3). Ο is Greek capital Omicron (Ο, U+039F). 0 is digit zero (U+0030).
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Did you know?
Uppercase O (O) is Unicode U+004F (decimal 79) — LATIN CAPITAL LETTER O in Basic Latin (ASCII). HTML5 has no named entity for it — type O directly, or use O / O when you need an entity form. Do not confuse it with accented forms like Ó (Ó) or Õ (Õ), Greek Omicron (Ο, Ο), or digit zero (0).
