CLIRMatrix is a large collection of bilingual and multilingual datasets for Cross-Lingual Information Retrieval. It includes:

• BI-139: A bilingual dataset of queries in one language matched with relevant documents in another language for 139x138=19,182 language pairs,
• MULTI-8, a multilingual dataset of queries and documents jointly aligned in 8 different languages.

In total, 49 million unique queries and 34 billion (query, document, label) triplets were mined, making CLIRMatrix the largest and most comprehensive CLIR dataset to date.