JSON can be stored as SQL Server NVARCHAR(MAX) data.
DBBlobEditor can help you to store JSON as SQL Server NVARCHAR(MAX) data:
Batch import json files into SQL Server TEXT / NTEXT / VARCHAR(MAX) / NVARCHAR(MAX)
Batch export SQL Server TEXT / NTEXT / VARCHAR(MAX) / NVARCHAR(MAX) to JSON files
Convert your data online, free
Free in-browser converters for CSV, Excel, JSON, XML and SQL: Withdata Online Data Conversion. Large files, batch conversion or scheduling? See the offline desktop apps, or browse all data conversion tools.