The development of emoji was predated by text-based emoticons, as well as graphical representations, inside and outside of Japan (for example, Microsoft’s Wingdings font, released in 1990, includes smiley and sad faces, and other symbols later incorporated into emoji). In the 1960s, Russian novelist and professor Vladimir Nabokov stated in an interview with the New York Times “I often think there should exist a special typographical sign for a smile — some sort of concave mark, a supine round bracket.”
The earliest known mobile phone in Japan to include a set of emoji was released by J-Phone on November 1, 1997. The set of 90 emoji included many that would later be added to the Unicode Standard, such as Pile of Poo, but as the phone was very expensive they were not widely used at the time.
In 1999, Shigetaka Kurita created the first widely used set of emoji. He was part of the team working on NTT DoCoMo‘s i-mode mobile Internet platform. Kurita took inspiration from weather forecasts that used symbols to show weather, Chinese characters and street signs, and from manga that used stock symbols to express emotions, such as lightbulbs signifying inspiration. Emoji were initially used (see Japanese mobile phone culture) by the Japanese mobile operators NTT DoCoMo, au, and SoftBank Mobile (formerly Vodafone). These companies each defined their own variants of emoji using proprietary standards. The first set of 176 12×12 pixel emoji was created as part of i-mode’s messaging features to help facilitate electronic communication, and to serve as a distinguishing feature from other services. Kurita created the first 180 emoji based on the expressions that he observed people making and other things in the city.
For NTT DoCoMo’s i-mode, each emoji is drawn on a 12×12 pixel grid. When transmitted, emoji symbols are specified as a two-byte sequence, in the private-use range E63E through E757 in the Unicodecharacter space, or F89F through F9FC for Shift JIS. The basic specification has 1706 symbols, with 76 more added in phones that support C-HTML 4.0.
Emoji pictograms by Japanese mobile phone brand Au are specified using the IMG tag. SoftBank Mobile emoji are wrapped between SI/SO escape sequences, and support colors and animation. DoCoMo’s emoji are the most compact to transmit while Au’s version is more flexible and based on open standards.
From 2010 onwards, some emoji character sets have been incorporated into Unicode, a standard system for indexing characters, which has allowed them to be used outside Japan and to be standardized across different operating systems.
Hundreds of emoji characters were encoded in the Unicode Standard in version 6.0 released in October 2010 (and in the related international standard ISO/IEC 10646). The additions, originally requested by Google (Kat Momoi, Mark Davis, and Markus Scherer wrote the first draft for consideration by the Unicode Technical Committee in August 2007) and Apple Inc. (whose Yasuo Kida and Peter Edberg joined the first official UTC proposal for 607 characters as coauthors in January 2009), went through a long series of commenting by members of the Unicode Consortium and national standardization bodies of various countries participating in ISO/IEC JTC1/SC2/WG2, especially the United States, Germany, Ireland (led by Michael Everson), and Japan; various new characters (especially symbols for maps and European signs) were added during the consensus-building process. Encoding in the Unicode standard has allowed emoji to become popular outside Japan. The core emoji set in Unicode 6.0 consisted of 722 characters, of which 114 characters map to sequences of one or more characters in the pre-6.0 Unicode standard, and the remaining 608 characters map to sequences of one or more characters introduced in Unicode 6.0. There is no block specifically set aside for emoji – the new symbols were encoded in seven different blocks (some newly created), and there exists a Unicode data file called EmojiSources.txt that includes mappings to and from the Japanese vendors’ legacy character sets. “Regional Indicator Symbols” were defined as part of this set of characters as an alternative to encoding separate characters for national flags.
The popularity of emoji has caused pressure from vendors and international markets to add additional designs into the Unicode standard to meet the demands of different cultures. Unicode 7.0 added approximately 250 emoji, many from the Webdings and Wingdings fonts. Some characters now defined as emoji are inherited from a variety of pre-Unicode messenger systems not only used in Japan, including Yahoo and MSN Messenger. Unicode 8.0 added another 41 emoji, including articles of sports equipment such as the cricket bat, food items such as the taco, signs of the Zodiac, new facial expressions, and symbols for places of worship. Corporate demand for emoji standardisation has placed pressures on the Unicode Consortium, with some members complaining that it had overtaken the group’s traditional focus on standardising characters used for minority languages and transcribing historical records.
Emoji characters vary slightly between platforms within the limits in meaning defined by the Unicode specification, as companies have tried to provide artistic presentations of ideas and objects. For example, following an Apple tradition, the calendar emoji on Apple products always shows July 17, the date in 2002 Apple announced its iCal calendar application for macOS. This led some Apple product users to initially nickname July 17 “World Emoji Day“. Other emoji fonts show different dates or do not show a specific one.
Some Apple emoji are very similar to the SoftBank standard, since SoftBank was the first Japanese network the iPhone launched on. For example, U+1F483 💃 DANCER is female on Apple and SoftBank standards but male or gender-neutral on others.
Journalists have noted that the ambiguity of emoji has allowed them to take on culture-specific meanings not present in the original glyphs. For example, U+1F485 💅 NAIL POLISH has been described as being used in English-language communities to signify “non-caring fabulousness” and “anything from shutting haters down to a sense of accomplishment”. Unicode manuals sometimes provide notes on auxiliary meanings of an object to guide designers on how emoji may be used, for example noting that some users may expect U+1F4BA 💺 SEAT to stand for “a reserved or ticketed seat, as for an airplane, train, or theater”.
As of July 2017 there were 2,666 emoji on the official Unicode Standard list.