The YCSB-JSON benchmark is an extension of the original YCSB benchmark to measure the performance of JSON databases. It extends the existing operations to JSON and defines new operations and workloads to cover the capabilities of JSON databases, such as nested objects, arrays, and query language. The benchmark aims to provide a comprehensive evaluation of the performance of JSON databases in supporting massively interactive applications. It includes various operations like insert, update, read, delete, scan, search, page, nestscan, arrayscan, and report, which can be combined to create different workloads. The YCSB-JSON implementation is available for Couchbase and MongoDB, and the source code is accessible on GitHub. The benchmark also includes a YAML file to generate customer and orders datasets.