Tencent Releases Chronicles-OCR, First Ancient Character Recognition Benchmark, GPT-5 and Gemini 2.5 Score Near Zero

Tencent Hunyuan and SSV Digital Culture Lab, in collaboration with the Institute of Computing Technology under the Chinese Academy of Sciences, released Chronicles-OCR on May 18, the first evaluation benchmark covering seven ancient font styles from oracle bone script to cursive script. The benchmark contains 2,800 expert-annotated images.

Testing of 28 mainstream multimodal large language models showed poor performance on ancient characters. GPT-5 and Gemini 2.5 Pro achieved near-zero scores on cross-era character detection, while the best-performing model reached only 16.5. Even with bounding boxes provided to skip localization, the highest accuracy was 27.1%, with Gemini 3.1 Pro achieving just 14.0% on oracle bone script.