9 Best Korean Grammar Checkers Tested 2026

You've written a Korean sentence. Is it grammatically correct?

The honest answer for most learners: you can't tell yet — that's the whole problem. So you reach for a tool. The bad news: most "Korean grammar checkers" online are either machine translations dressed up as grammar tools, or basic spell-check that misses the things you actually need help with (particles, verb endings, formality level).

We tested every free Korean grammar checker we could find on the same sample sentences — ranging from beginner mistakes ("저는 학생 입니다") to intermediate errors (wrong particle, mismatched politeness level). Here's how they compare.

Quick Comparison Table

Tool	Catches particles?	Catches politeness?	Free tier?	Best for
Pusan University 맞춤법/문법 검사기	✅	✅	✅ (unlimited)	Native-level grammar check
Naver 맞춤법 검사기	Partial	❌	✅ (300 chars)	Quick spelling + basic grammar
ChatGPT (GPT-4)	✅	✅	✅ (limited daily)	Explanation + correction
Claude	✅	✅	✅ (limited daily)	Detailed explanation
DeepL Write (Korean)	Partial	Partial	✅	Style + flow
Naver Papago	Partial	—	✅	Translation cross-check
Grammarly	❌	❌	n/a	❌ Doesn't support Korean
LanguageTool	❌	❌	✅	English + 20+ languages (Korean basic)
HiNative	✅	✅	✅	Native speaker correction (slow but accurate)
HanCom 맞춤법 검사기	Partial	❌	Built into HanCom Office	Korean office workers' default

TL;DR ranking by use case:

• Best overall (free): Pusan University 검사기 — purpose-built for Korean
• Best for explanation: ChatGPT or Claude
• Best for native correction: HiNative (human-powered)
• Best for quick proofreading: Naver 맞춤법 검사기
• Don't bother: Grammarly (no Korean), LanguageTool (Korean coverage is minimal)

1. Pusan University Grammar Checker (부산대 맞춤법 검사기)

The gold standard. Built by Pusan National University's NLP lab and used by Korean publishers, journalists, and academics. It catches spacing errors, spelling, basic grammar, and offers usage explanations in Korean.

Pros:

• Catches subtle particle errors (을/를, 이/가, 은/는)
• Handles polite/formal level inconsistencies
• Explanations cite Korean grammar rules
• Unlimited input length

Cons:

• Interface is Korean-only
• No mobile app
• Explanations are in Korean — frustrating if you're a beginner

Who it's for: intermediate and advanced learners who can read Korean explanations.

2. Naver 맞춤법 검사기

Naver's built-in spelling + grammar tool. Fast, ubiquitous, and Korean speakers' default for casual writing.

Pros:

• Instant results
• Catches the most common spelling/spacing mistakes
• Free, no signup
• Works inside the Naver mobile app

Cons:

• 300-character limit per check
• Doesn't explain why something is wrong
• Misses subtle particle/politeness errors

3. ChatGPT (GPT-4 or GPT-4o)

Not a dedicated tool, but the best free option for explanations. Paste your Korean and ask: "Please check this for grammar and explain corrections in English."

Pros:

• Bilingual explanations (Korean + English)
• Catches particles, verb endings, politeness, register
• Handles long passages
• Can adjust tone ("make this more formal" / "more casual")

Cons:

• Free tier rate-limited
• Occasionally invents corrections that aren't actually wrong

Prompt template:

"Please check the following Korean sentences for grammar errors. For each correction, explain in English what the rule is and why my original was wrong. Korean: [paste here]"

4. Claude (Anthropic)

Similar to ChatGPT but often gives more detailed grammatical explanations. Particularly strong on politeness-level analysis.

Pros:

• Long context (you can paste an entire essay)
• Detailed reasoning chains
• Less prone to hallucinated corrections than smaller models

Cons:

• Free tier limits

5. DeepL Write (Korean)

DeepL's writing assistant supports Korean. Better at style/flow than strict grammar.

Pros:

• Suggests more natural phrasings
• Catches awkward word order
• Free with no signup

Cons:

• Misses some particle/conjugation errors

6. Naver Papago

Papago is Naver's translator, not a grammar checker — but it doubles as a cheap correction tool when paired with reverse translation. Type your Korean sentence, translate it to English, and see if the English matches your intended meaning. If the English is broken, your Korean has a structural problem.

Pros:

• Free, fast, no signup
• Mobile app with voice input
• Korean ↔ English is its strongest pair

Cons:

• Doesn't flag errors directly — you have to interpret the bad translation
• Misses politeness-level mistakes (translations smooth them over)

Who it's for: learners who want a quick sanity check on whether a sentence makes sense, not a strict grammar audit.

7. Grammarly

Verdict: Skip. Despite supporting many languages, Grammarly does not check Korean grammar as of 2026. If you see Grammarly suggested for Korean elsewhere, the recommendation is outdated.

8. LanguageTool

Multi-language grammar checker. Officially supports Korean but the rule coverage is sparse.

Pros:

• Open source, self-hostable

Cons:

• Korean rule set is small; misses most learner errors

9. HiNative

Not a grammar checker — a Q&A app where native speakers correct your writing for free. Slower (minutes to hours) but more accurate than any automated tool.

Pros:

• Real native correction
• Explanations in your native language
• Cultural notes ("grammatically correct but no one says it like that")

Cons:

• Not instant
• Quality depends on which native speaker answers

Bonus: HanCom 맞춤법 검사기

If you write in HanCom (Korea's default office suite), the built-in checker is decent — comparable to Naver for spelling/spacing.

The Strongest Free Workflow

The combination we recommend:

1. First pass: Pusan University checker for hard grammar errors
2. Second pass: ChatGPT or Claude with the prompt template above for explanation and style polish

This catches more than any single tool and costs nothing. Total time: about 5 minutes per paragraph.

Beyond Tools: Other Ways to Check Your Korean

When tools fail you (and they will), three habits build accurate grammar over time:

• Keep a personal error log. Every time you make the same mistake twice, write the rule down. Patterns repeat.
• Read aloud. Many Korean grammar errors sound wrong even if they look fine on paper.
• Find a tutor for a 25-minute correction session. A native Korean teacher can fix in 25 minutes what would take you hours with tools alone. KTalk Live's free trial includes exactly this.

How We Tested

We ran the same five Korean sentences through every tool on this list. The sentences ranged from a beginner mistake ("저는 학생 입니다" with the wrong spacing and missing particle) up to an intermediate error where a writer mixed -요 and -ㅂ니다 endings in the same paragraph.

Each tool was scored on four things: particle accuracy (did it catch wrong 을/를 or 이/가?), verb conjugation (did it catch -아요 vs -어요 mix-ups and irregular endings?), politeness consistency (did it flag a polite-and-formal mix in one passage?), and explanation quality (did it tell you why, or just correct silently?).

We excluded paid-only tools. Many learners are early in their Korean journey and shouldn't pay $20 per month for a checker before they even know which kinds of errors they make. Every tool on this list has a free tier that's enough for daily homework, journaling, or quick text checks.

One caveat: results depend on what you write. A tool that nails particle errors may miss politeness mistakes. The ranking is for the average learner — your mileage may vary if your weak spot is unusual.

Frequently Asked Questions

What's the best free Korean grammar checker?

Pusan University's 맞춤법/문법 검사기 is the best free tool overall. It is built for Korean and used by Korean newspapers. It catches particle and politeness errors that most tools miss. The explanations are in Korean, so a beginner may want to pair it with ChatGPT for English notes.

Does Grammarly check Korean?

No. Grammarly does not support Korean as of 2026. It only checks English and a few European languages. If a guide tells you to use Grammarly for Korean, the guide is old. Use Pusan University, Naver, or ChatGPT instead.

Can ChatGPT check Korean grammar?

Yes. ChatGPT is one of the best free tools for understanding why a sentence is wrong. Paste your Korean and ask it to explain each fix in English. GPT-4 catches particles, verb endings, and politeness mix-ups. Sometimes it invents fake corrections, so cross-check with Pusan University.

Why do grammar checkers miss particle errors?

Particles in Korean depend on meaning, not just spelling. The "wrong" particle is often still a valid word — it just changes the focus of the sentence. Most checkers do not read for meaning, so they let particle mistakes slip through. Pusan University and ChatGPT are the two that catch them well.

Should I use a checker or a tutor first?

Use a checker for daily homework and quick texts. Use a tutor when you want to know why you keep making the same mistake. A 25-minute lesson with a native teacher fixes patterns that no tool can spot — like word choice that sounds awkward to Koreans even when the grammar is right. Use both. They do different jobs.

What's Next

Once you have a checker workflow you trust, the bigger payoff is preventing mistakes in the first place. Solidify your verb endings with our Korean Verb Conjugation guide, or work on natural phrasing with How to Say No in Korean.