JMTEB and JMTEB-lite: Japanese Massive Text Embedding Benchmark and Its Lightweight Version
Proceedings of the Fifteenth Language Resources and Evaluation Conference (LREC 2026)
Abstract
We present JMTEB, a large-scale evaluation suite for Japanese text embedding models, designed to provide comprehensive coverage across multiple task types. The benchmark integrates 28 datasets across 5 tasks, enabling broad and challenging evaluation of model performance in diverse scenarios. While the full benchmark delivers thorough assessment, its scale poses practical challenges in terms of computation time and resource requirements. To address this, we construct JMTEB-lite, a lightweight version of JMTEB, by substantially reducing corpus size in retrieval-related tasks. JMTEB-lite significantly accelerates evaluation while maintaining high fidelity to the full benchmark. Together, JMTEB and JMTEB-lite form a flexible evaluation framework: the full version serves as a comprehensive standard for exhaustive benchmarking, while the lightweight version enables rapid iteration and efficient model selection. This dual approach facilitates both rigorous evaluation and practical development workflows, supporting the advancement of Japanese text embedding research.