Hangul Day: Why Perfect Hangul Feels “Inefficient” to Computers

Today is October 9 — Hangul Day.

King Sejong’s Hangul is recognized as one of the most logical and scientific writing systems in the world. It represents sounds through precise combinations of symbols, and anyone can learn to read and write it within hours — simple, systematic, and beautiful.

But here’s something surprising: when Hangul enters a computer, this perfect system suddenly becomes inefficient. Why does that happen?

Computers Only Understand 0s and 1s

Computers don’t “see” text, images, or music the way we do. They convert every piece of information into 0s and 1s, representing electricity flowing (1) or off (0). Each tiny signal is called a bit, and eight bits together make one byte.

1 byte = 8 bits = 2⁸ = 256 possible combinations (0–255)

Think of a bit as a single light bulb that’s either on or off, and a byte as a pattern created by eight bulbs. By combining these patterns, computers express letters, numbers, and everything else.

English Uses 1 Byte, Hangul Needs 2–3 Bytes

English has only 26 letters (A–Z), so one byte is enough to represent every character.

A → 01000001
B → 01000010

Each English letter fits neatly inside one byte.

Hangul, however, works differently. It’s combinational — letters are formed by joining consonants and vowels:

가 = ㄱ + ㅏ
값 = ㄱ + ㅏ + ㅂ + ㅅ

So when you type “가,” the computer actually thinks:

“Load ㄱ, then load ㅏ, combine them, and display as ‘가.’”

That’s why one byte isn’t enough. Each Hangul syllable typically takes 2–3 bytes.

If English needs a one-drawer cabinet, Hangul needs three drawers to store its combinations. As a result, “가나다” takes two to three times more storage space than “ABC.” A document that’s 1 MB in English could easily reach 2–3 MB in Hangul.

A Quick Comparison With Other Languages

English is simple to stack letter by letter, while Hangul must be combined, Chinese contains thousands of symbols, and Japanese mixes two character sets. In short, all non-English languages pose similar difficulties for computers.

Hangul’s “Assembly-Style” Structure Adds Extra Work

English is like stacking ready-made Lego blocks.
Hangul is like building each Lego piece first, then putting it together.

This assembly process means more calculations for the CPU, and makes input systems, font engines, and rendering pipelines more complex.

Fonts Are Twice as Hard to Design

English fonts only need to line characters horizontally. Hangul characters must arrange consonants and vowels vertically and horizontally within a square frame.

For example, “가” and “고” differ only in vowel position, yet look completely different. Font designers must define all these positional rules, and rendering engines must compute them on the fly.

🎨 English fonts stamp letters in a row.
Hangul fonts are artisans carving new stamps for every shape.

Why Developers Rarely Use Hangul in Code

If you’ve ever programmed, you’ve probably named variables in English — name instead of “이름.” Here’s why:

1️⃣ Programming languages are built on English.
English letters are processed directly; Hangul must be converted into Unicode first.

2️⃣ Different systems use different encodings.
Windows, macOS, and Linux save Hangul in slightly different ways — EUC-KR, UTF-8 (NFD), UTF-8 (NFC) — so the same file might display broken text on another system.

3️⃣ Search and collaboration issues.
Non-ASCII variable names may break tools or confuse other developers. That’s why most teams follow the rule:

“Use English for code, Hangul for comments.”

Hangul Is Still the Most Efficient Script for Humans

All of this “inefficiency” exists only from the computer’s perspective. For humans, Hangul is incredibly efficient — logical, phonetic, easy to read and learn. The problem isn’t the writing system; it’s that computers were built around English-based design.

The “Digital Sejong Project”

We now know that computers, not Hangul, are the inefficient ones. Efforts to create more compact Hangul encodings actually began decades ago — the combinational Hangul code (KS X 1001, 1987) — but it failed to gain global support because Unicode became the universal standard. It was efficient but incompatible with the rest of the world.

Today, the landscape is changing. Artificial intelligence can do more than store symbols — it can understand how language is structured. That means we may not need to change global standards at all; instead, we can optimize Hangul processing inside the system itself.

AI models can learn how consonants and vowels combine, generate syllables dynamically instead of loading them as images, and predict inputs or render text more efficiently. These aren’t science fiction — they’re emerging research topics.

We don’t yet have perfect answers, but the direction is clear: our goal is not to change Hangul, but to help computers understand it.

If King Sejong created Hangul for his people, then it’s our generation’s turn to let computers read and write it as naturally as we do. When that day comes, Hangul will no longer just be a beautiful script — it will become one of the most efficient and intelligent writing systems in the digital world.

“If the next generation of programmers, together with AI, designs a new code system for Hangul, that would truly be the Digital Sejong Project.”

Thank you for reading — and happy Hangul Day! 🌿

You can view the original blog post in Korean at the links below:

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