Keycap: 0 Emoji

The number zero keycap (0️⃣). It's the digit people use the least, on the emoji search list it ranks dead last, and it took civilization about two thousand years to accept as a real number. Most people think of zero as obvious. It isn't. Ancient Greeks refused to give it a symbol because "nothing" couldn't logically be "something." Romans had no zero at all, which is why Roman arithmetic is terrible. The Indian mathematician Brahmagupta wrote the first formal rules for zero in 628 CE in his treatise Brahmasphutasiddhanta, defining it as the result of subtracting a number from itself. That idea traveled through the Islamic world (via al-Fazārī's Arabic translation) and didn't fully reach Europe until Fibonacci's *Liber Abaci* in 1202. A number we consider obvious today took roughly 1,600 years to become common sense.

On a phone, 0 is where you go when the menu fails you. "Press 0 to speak with an agent" is the universal escape hatch from IVR hell, built into most corporate phone trees as the polite bypass that lets callers skip the robot. In texting, 0️⃣ means the start of a list (when people are being weird), a score of nothing in sports, or a sarcastic flourish: "I have 0️⃣ interest, 0️⃣ energy, 0️⃣ patience for this." It's the emoji of negation.

In computing, 0 is one half of everything. Claude Shannon's 1937 MIT master's thesis proved that Boolean logic (true/false, 1/0) could be implemented with electrical switches. Every computer program you've ever run is a shuffled pile of zeros and ones. The emoji on your keycap is, at the lowest level, encoding itself in the thing it represents.

0️⃣ is the runt of the keycap family. In Google Trends data for "N emoji" searches, it scores about 5 out of 100 in Q1 2026. Compare that to 2️⃣ at 90, 3️⃣ at 69, or even 9️⃣ at 17. People just don't look it up. The reason is structural: when you write a numbered list, you start at 1, not 0. The only people who begin at zero are programmers, and they're not searching Google for the keycap zero emoji.

When 0️⃣ does appear in posts, it's mostly for emphasis. "I have 0️⃣ regrets." "0️⃣ crumbs left." "This take is giving 0️⃣ chill." Replacing the word "zero" with the keycap adds a visual pop that plain text can't match. It's the numeric equivalent of a rhetorical flourish.

The other main use is sports, gaming, and betting contexts. A shutout score (3-0️⃣), a zero-kill game, 0/10 would not recommend, a rating of complete disdain. In Black Twitter's "0/10" and "0 chill" usage patterns, the number zero carries weight that positive numbers can't — it signals absolute, bottom-of-the-barrel rejection.

Gaming livestreams and esports clips use 0️⃣ for dunking. "Kills: 0️⃣" under a screenshot of a terrible performance gets laughs that "Kills: zero" never would. The keycap turns criticism into a visual punchline.

The digit 0 has one of the longest origin stories of any symbol on a phone keypad. Ancient Babylonians used a placeholder symbol around 300 BCE, but it only marked empty positions within numbers. It wasn't a number in its own right. The Greek mathematician Ptolemy used a small circle (ο) as a placeholder in astronomical tables around 130 CE, but Greek philosophy broadly rejected zero because "nothing" couldn't logically exist. Romans, famously, had no zero at all, which is why multiplying XLVII by LXXXIV is a war crime.

The breakthrough came in India. Aryabhata used a placeholder around 499 CE. A century later, Brahmagupta (c. 598–668 CE) formalized zero as a number in *Brahmasphutasiddhanta* (628 CE), writing rules that still hold: subtracting a number from itself gives zero, any number times zero is zero, any number plus zero is itself. He even tried to divide by zero (he got it wrong, but he was the first to take the question seriously).

Brahmagupta's work traveled west via al-Fazārī's 8th-century Arabic translation, arriving at the court of Caliph al-Mansur. Persian mathematician al-Khwarizmi adopted Indian numerals (the ancestors of today's 0-9) in the 9th century. Europe took its sweet time: Fibonacci's *Liber Abaci* (1202) introduced Arabic numerals to Western Europe, but Italian merchants used Roman numerals well into the 15th century because city councils distrusted zero (they worried it was easier to forge, since anyone could add a zero to a number to inflate it).

The phone keypad gave zero its modern visual home. AT&T's Bell System introduced the 12-button touch-tone keypad in 1963, with 0 sitting alone on the bottom row flanked by * and #. That placement wasn't arbitrary: on rotary phones, 0 was the operator's number, and the touch-tone keypad preserved that role. To this day, pressing 0 in a corporate phone tree is the usual way to reach a human, a design pattern inherited from the operator era.

Unicode finally gave 0 an emoji in Emoji 3.0 (2016), encoded as a three-character sequence: the digit 0 (U+0030), a variation selector (U+FE0F), and the combining enclosing keycap (U+20E3), which was itself added to Unicode 3.0 back in 1999. The sequence is technically a composition, not a single character, which is why pasting 0️⃣ into some legacy systems produces three separate glyphs.

Encoded as U+0030 U+FE0F U+20E3 — the digit 0 plus variation selector plus combining enclosing keycap. The base character "0" has been in Unicode since 1.1 (1993). The enclosing keycap (U+20E3) was added in Unicode 3.0 (1999). The full keycap sequence joined Emoji 3.0 in 2016.

1. 628Brahmagupta formalizes zero as a number in Brahmasphutasiddhanta↗
2. 820al-Khwarizmi's treatises adopt Indian numerals, spreading zero through the Islamic world
3. 1202Fibonacci introduces Arabic numerals (including zero) to Europe in Liber Abaci↗
4. 1299Florence bans Arabic numerals for commerce, fearing forgery by adding zeros
5. 1937Claude Shannon's MIT master's thesis shows Boolean algebra (true/false as 1/0) maps to electrical circuits↗
6. 1945'Ground zero' coined as military slang at the Trinity atomic test site, New Mexico↗
7. 1963AT&T introduces 12-button touch-tone keypad with 0 on the bottom row between * and #
8. 1975Khmer Rouge regime declares 'Year Zero' in Cambodia, signaling cultural reset attempt↗
9. 1999Combining Enclosing Keycap (U+20E3) added to Unicode 3.0↗
10. 2001'Ground Zero' re-enters mainstream vocabulary after the September 11 attacks↗
11. 20160️⃣ Keycap Digit Zero added to Emoji 3.0↗

In Chinese culture, 0 (零, líng) is generally positive. It sounds similar to 良 (liáng, "good") and represents a beginning, wholeness, and the fresh start of a cycle. It's not as lucky as 8 (八, prosperity) but it's not cursed like 4 (四, death). Chinese phone numbers often include zeros without superstition.

In Japan, zero (零, rei or ゼロ, zero) carries neutral connotations. Japanese superstitions focus on 4 and 9 rather than zero. "Zero" itself is a borrowed English word used widely in business and consumer culture: "zero calorie," "zero emission," "zero waste" are all common marketing terms.

In Western culture, zero is philosophically freighted. "Ground zero" originated as military slang for the point directly beneath an atomic detonation — the Trinity Test site in New Mexico, July 16, 1945. The term entered general usage after a 1946 *New York Times* report on Hiroshima and was redefined for a new generation after the September 11, 2001 attacks on the World Trade Center.

"Year Zero)" is a darker cultural term. Pol Pot's Khmer Rouge regime, taking inspiration from the French Revolutionary Calendar's "Year One"), attempted to reset Cambodian society starting in 1975. The results were catastrophic: an estimated 1.5 to 2 million dead from executions, famine, and forced labor. The phrase "Year Zero" has since become shorthand for any attempt to erase a society's past, usually by force.

In sports, zero is the universal language of failure. A shutout in hockey, baseball, or soccer. A nil-nil draw in European football. In tennis, "love" means zero — possibly from the French l'œuf ("the egg"), a visual metaphor for the shape of the number. "Duck" in cricket is the same idea: a batter out for zero runs leaves the field in the shape of a duck egg.

• •Brahmagupta (598–668 CE) wrote the first formal rules for zero as a number in 628 CE.
• •Claude Shannon's 1937 master's thesis proved that Boolean logic (true/false, 1/0) maps directly to electrical switch circuits. Every computer runs on his idea.
• •'Ground zero' was originally code for the Trinity atomic test site on July 16, 1945. It entered general vocabulary after a 1946 New York Times Hiroshima report.
• •Pressing 0 on a corporate phone tree is the standard way to reach a human agent, inherited from the era when 0 was the operator's number on rotary dials.
• •Tennis uses 'love' for zero, likely from the French l'œuf (the egg) — a visual pun on the round shape of the digit.
• •0️⃣ is the least-searched of all thirteen keycap emojis on Google Trends, scoring about 5 out of 100 compared to 2️⃣'s 90.
• •AT&T introduced the 12-button touch-tone keypad in 1963, putting 0 alone on the bottom row between * and # — a layout still visible on every phone dialer app.

• •Some readers confuse 0️⃣ with ⭕ (hollow red circle used to mark "correct" in Japan) because both involve circles. They mean opposite things.
• •Using 0️⃣ as the start of a numbered list reads as a programming joke (zero-indexing). Non-programmers usually find it confusing.
• •'I give this 0️⃣/10' is occasionally read as a typo for 10/10 when the slash is ambiguous. Add a space or use '0/10' with words for clarity.

• •Year Zero): Pol Pot's Khmer Rouge regime attempted a cultural reset starting in 1975. The phrase has since become shorthand for any forced erasure of a society's past.
• •Ground Zero: coined at the Trinity atomic test in 1945, redefined for the World Trade Center site after September 11, 2001.
• •The Year 2000 problem (Y2K): the panic that computers storing dates as two-digit years (99 → 00) would interpret 2000 as 1900. Billions were spent patching systems. Almost nothing went wrong on January 1, 2000.
• •Zero to Hero (Disney's Hercules, 1997): the animated summary of Hercules's rise from nobody to Olympian, condensed into a Gospel-inflected Muses number.
• •Zero Dark Thirty (Kathryn Bigelow, 2012): military slang for 12:30 AM, the title framing the raid on Osama bin Laden's compound as something that happens in the dead of night.

• •Keycap emojis are three-code-point sequences. If you strip U+FE0F during normalization, 0️⃣ will render as a plain 0 on systems that need the variation selector.
• •U+0030 (ASCII zero) and U+20E3 are both in the Basic Multilingual Plane. You can encode the sequence in UTF-8, UTF-16, or UTF-32 without surrogate pair concerns.
• •In JavaScript, "0️⃣".length"0️⃣".length returns 3. Array.from("0️⃣").lengthArray.from("0️⃣").length also returns 3. Use a grapheme segmenter (Intl.Segmenter) if you need to count it as one visible character.
• •CSS grapheme handling: font-variant-emoji: emoji; can force the keycap rendering when the system defaults to text presentation.

See the full Emoji Developer Tools guide for regex patterns, encoding helpers, and more.