Modern Korean uses 24 basic jamo, but the original alphabet created in 1443 included several more letters that have since become obsolete. This reference lists those archaic jamo with their sounds and code points, and can scan a passage to find them.
Historical background
King Sejong introduced Hangul (then called Hunminjeongeum, “correct sounds for the instruction of the people”) in 1443 with 28 letters covering distinctions in Middle Korean pronunciation that no longer exist in modern Korean. Over the following centuries, several sounds merged or disappeared entirely, making their corresponding letters redundant. By the twentieth century, orthographic reform and standardisation had reduced the working alphabet to 24 jamo, dropping the letters whose sounds had vanished.
These obsolete letters are still encountered in:
- Classical texts from the Joseon dynasty (1392–1897)
- The Hunminjeongeum itself and its explanatory text (Hunminjeongeum Haeryebon)
- Jeju dialect transcription, where some archaic pronunciations survive in the spoken language
- Historical linguistics and Korean Studies coursework
The obsolete jamo
ㆍ araea low back vowel between a and o (merged into ㅏ/ㅡ)
ㅿ bansiot voiced [z] (merged into ㅅ / zero)
ㆆ yeorinhieut light glottal [ʔ] onset
ㆁ old ieung initial velar nasal [ŋ] (merged into ㅇ)
ㅸ kapyeoun bieup light b, a [β]/w-like fricative
ㆅ kapyeoun hieut a lighter [h]-like sound, now mergedㆍ Araea — the “lower dot”
Perhaps the most famous obsolete jamo, araea represented a sound between modern ㅏ and ㅡ, transcribed in linguistics as [ə] or [ɐ]. It merged into ㅏ and ㅡ in standard Korean during the eighteenth century but survives in Jeju as a distinct vowel. You see araea today in the Jeju dialect ISO code and in its stylised use in the word 한글날 (Hangeul Day) on some decorative materials.
ㅿ Bansiot — the half-siot
Represented a voiced [z] sound that existed in Middle Korean. As Korean lost its voiced/voiceless consonant distinction at word boundaries, bansiot merged with ㅅ or simply disappeared, leaving no modern reflex in standard speech.
ㆁ Old ieung — the ng-ieung
Marked an initial [ŋ] sound (as in English “singing”). Modern Korean lost this initial ng sound entirely; the letter merged with the silent initial ㅇ. You will see old ieung in classical texts where modern Korean would use plain ㅇ or drop the initial consonant.
How the scanner works
The scanner walks your text character by character and reports any that belong to this obsolete set, with a count for each, so you can quickly tell whether a document uses pre-modern orthography. Most obsolete jamo occupy the Hangul Compatibility Jamo block (U+317F to U+318E) and display correctly only in fonts that include old Hangul glyphs — Noto Sans Old Hangul, Malgun Gothic (some versions), and specialised fonts used by Korean digital humanities projects.
For modern transcription, araea is normally replaced by ㅏ or ㅡ and old ieung by plain ㅇ. Everything runs locally in your browser — nothing you paste is sent to a server.