Same model, four languages: the top barely moves, the middle swings by forty places

Ninety-one models are ranked in English, French, German and Spanish on the same protocol. Claude Fable 5 is third in all four; Claude Opus 5 first or second. Below the top, GLM 5.3 Flash is 10th in English and 54th in German, Grok 4.6 25th in English and 60th in French, and the best local model is a different model in every language.

The four editions of this benchmark share the same models, the same judges and the same protocol. Only the prompts change: 240 per language, written natively. So when a model ranks 10th in English and 54th in German, the difference is not the method. It is the model.

Ninety-one model variants have a published score in all four languages (data as of 19 September 2026). Here is how far they travel. The figures and ranks in the text date from that export; the charts are recomputed at each update and may differ.

The six steadiest models: Claude Fable 5 is third everywhere, Claude Opus 5 first or second

The models that keep their rank in every language

Rank in each edition of the six models whose rank moves least across the four languages. Rank 1 is at the top.

1RankEnglishFrenchGermanSpanish3 · Claude Fable 531 · Claude Opus 521 · Claude Fable 5.149 · GPT-5.6 Sol97 · GPT-6 Astra55 · Claude Opus 4.87
View as a data table
ModelEnglishFrenchGermanSpanish
Claude Fable 53333
Claude Opus 52111
Claude Fable 5.14221
GPT-5.6 Sol9969
GPT-6 Astra5647
Claude Opus 4.87485

Source: AI Writing Benchmark, duels published as of 20 September 2026, English edition.

PNGaiwritingbenchmark.com

The six models whose rank moved least were Claude Fable 5, Claude Opus 5, Claude Fable 5.1, GPT-5.6 Sol, GPT-6 Astra and Claude Opus 4.8. None moved by more than four places and none left the top nine in any language. GPT-5.6 Sol was ninth in three languages and sixth in German. Kimi K3 also moved four places, as many as Claude Opus 4.8, and just misses the chart: first in English, fourth or fifth elsewhere. It was the only open-weight model near the top in all four languages.

The scores tell the same story with a nuance: Claude Opus 5 scores 93.7 in English and 99.5 in French, meaning the French field is easier for it to dominate, not that it writes better French than English. Scores are only comparable within a language.

Below the top, the same model can be 10th in one language and 54th in another

Same model, four ranks

Rank in each edition of the six models with the widest spread, among the 91 models ranked in all four languages. Rank 1 is at the top.

1204060RankEnglishFrenchGermanSpanish44 · GLM 5.3 Flash1054 · Qwen3.8 27B Q4_K_M2765 · Ling 3.0 Flash Q4_K_M6621 · Grok 4.62551 · Hy31543 · Seed 2.1 Turbo ↯57
View as a data table
ModelEnglishFrenchGermanSpanish
GLM 5.3 Flash10275444
Qwen3.8 27B Q4_K_M27175854
Ling 3.0 Flash Q4_K_M66357665
Grok 4.625605221
Hy315432551
Seed 2.1 Turbo ↯57286143

Source: AI Writing Benchmark, duels published as of 20 September 2026, English edition.

PNGaiwritingbenchmark.com

GLM 5.3 Flash is a top-ten model in English and a bottom-half model in German. Grok 4.6 is strong in English and Spanish, weak in French and German. Hy3 is good in English, mediocre everywhere else. These are not sampling accidents: each model has between 1,000 and 1,800 ranked duels per language, and the confidence intervals are a few points wide.

Local models show the same pattern with an extra twist. Qwen3.8 27B at Q4_K_M is the best local model in French, 17th overall, and one of the weakest in German, 58th. The same file, on the same machine, with the same reasoning setting. Whatever Qwen learned about French, it did not learn about German.

The best local model is a different model in every language, and the gap to the cloud is widest in German and Spanish

Best model versus best local model

Score of the leader of each edition and of its best locally run model. Scores are only comparable within a language.

English93.8 · Kimi K377.4 · Muse Glimmer 30B K-Quant Dynamic (18th)French99.5 · Claude Opus 576.6 · Qwen3.8 27B Q4_K_M (17th)German98.0 · Claude Opus 572.1 · Gemma 4 31B Q8_0 (24th)Spanish98.3 · Claude Fable 5.170.4 · Qwen3.8 27B Q8_0 (23rd)
  • Best model
  • Best local model
View as a data table
Best modelBest local model
EnglishKimi K3, 93.8Muse Glimmer 30B K-Quant Dynamic, 77.4 (18th)
FrenchClaude Opus 5, 99.5Qwen3.8 27B Q4_K_M, 76.6 (17th)
GermanClaude Opus 5, 98.0Gemma 4 31B Q8_0, 72.1 (24th)
SpanishClaude Fable 5.1, 98.3Qwen3.8 27B Q8_0, 70.4 (23rd)

Source: AI Writing Benchmark, duels published as of 20 September 2026, English edition.

PNGaiwritingbenchmark.com

Muse Glimmer 30B wins the local field in English, Qwen3.8 27B in French and Spanish, Gemma 4 31B in German. Nobody who reads only one leaderboard would guess that. The distance to the best cloud model is 16 points in English, 23 in French and 26 to 28 in German and Spanish: the further from English, the more a local setup gives up.

What to take from it

Reading an English leaderboard to choose a model for German is a mistake for about a third of the field. The frontier closed models are safe in every language we test. Below them, check the edition in your language, and if you run models locally, check the specific quantization: the file that wins in one language can lose in the next.

Conclusion

The frontier models are frontier in every language, and the open-weight field is not. If you write in French, German or Spanish, an English-only leaderboard will mislead you about a third of the models; read the edition for your language, and if you run models locally, check the specific quantization there too.