We test how well AI actually understands Indonesian and its regional languages, map the words that trip up native speakers, and publish the numbers along with the raw data and their limits, including when the results are not what we hoped for.
GPT-6 Astra scored 42 of 42 on the public half of our Indonesian slang benchmark, the joint best result in the panel. Counting the 18 withheld items too, it finished 59 of 60, 1 behind OpenAI's own cheaper GPT-5.6 Luna. 1 item apart on 60 is not a statistically meaningful gap, and that is the more interesting finding: the public half no longer separates the strongest models at all.
We tested two free NVIDIA models on 42 Indonesian slang questions. Nemotron Super, 120 billion parameters, answered 34 correctly; Nemotron 3.5 Lightning answered 26; both still trail Gemma at 31 billion parameters, priced at pocket change.
The two smallest models we have ever tested, LFM2.5 at 2.6 billion parameters and hy-mt2 at 1.8 billion, faced off on 60 Indonesian slang questions. The scores ended in a dead heat, but the two failed in opposite ways, and one of them tried calling Google mid-exam.
Our slang test offered free answers to anyone reading options. Yet, AI models grabbed at most 1.00 out of 4.1 items.