Best AI models for Korean

The same text can need a different number of tokens in Korean than in English, and the gap depends on the model. We measured it ourselves, then combined it with independent quality scores and current prices to show which models give the best results for your money in Korean.

The same text needs 20% to 89% more tokens in Korean than in English, depending on the model. Meta (Llama 4) is the most efficient, Z.ai (GLM-4.5) the least.

The cost of Korean, by model family

TokenizeriTokens (English)Tokens (Korean)Extra vs English
Meta (Llama 4)219263
+20%
Mistral (Nemo)220286
+30%
Google (Gemma 3)218284
+30%
OpenAI (GPT-4o)219305
+39%
Alibaba (Qwen 3)219355
+62%
DeepSeek (V3.1)219363
+66%
Z.ai (GLM-4.5)219413
+89%

Anthropic (Claude) and xAI (Grok) do not publish their tokenizers, so they cannot be measured; for their models we use the average of the measured families (marked ≈). Google’s Gemini is estimated with Google’s open Gemma tokenizer.

Most capable models and their real cost in Korean

Rankings →
ModelOverall indexiKorean factorInputi1,000 pages
166.6×1.39$10$4.72
165.0≈ ×1.48$10$5.01
163.6≈ ×1.48$10$5.01
Claude Opus 5Anthropic
162.7≈ ×1.48$5$2.51
162.5×1.39$30$14.15
162.0×1.39$2$0.943
159.3×1.39$2$0.943
GPT-5.5OpenAI
159.3×1.39$5$2.36
159.1×1.39$30$14.15
158.3≈ ×1.48$5$2.51
Gemini 3.7 FlashGoogle DeepMind
157.7×1.30$0.75$0.329
Kimi K3Moonshot AI
157.7≈ ×1.48$3$1.50
Gemini 3.8 FlashGoogle DeepMind
157.1×1.30$0.75$0.329
156.9×1.20$1.25$0.508
GPT-5.4OpenAI
156.9×1.39$2.50$1.18

Cost to read 1,000 pages of text (about 300,000 words in English) written in Korean, as input. Each model gets the factor measured on its company’s latest public tokenizer, so treat it as an estimate: newer models may use a different tokenizer. ≈ marks companies that publish no tokenizer (average of measured families).

Best value for Korean

Strong models (overall index 140 or more), cheapest first for processing Korean text.

Tips for using AI in Korean

  1. Ask for answers in Korean explicitly, especially when your question contains English terms; otherwise some models switch to English.
  2. Test with your own content. Quality scores are measured mostly in English, so try your finalists on real Korean examples before you decide.
  3. Compare token costs. Depending on the model, the same content in Korean costs between +20% and +89% compared with English, and Meta (Llama 4) handles it most efficiently.
  4. Name your audience. Vocabulary, tone and formality vary between regions and situations: tell the model who you are writing for and how formal it should be.
  5. Proofread names, numbers and punctuation. Generated text can be fluent yet get proper names, dates or local conventions wrong, so review anything you publish.

How we measured

We wrote the same four texts (a news item, a customer email, a technical explanation and travel tips) in 15 languages, then counted the tokens that each public tokenizer produces. Quality scores come from Epoch AI and are measured mostly in English, so always test the finalists on your own Korean content.

Get a personal recommendationCount the tokens of your own text