About BSON ↔ JSON

Convert between BSON hex and JSON. Part of the DevTools Surf developer suite. Browse more tools in the Converters collection.

Use Cases

• Debug MongoDB wire protocol messages during driver development
• Inspect raw BSON data from database exports
• Convert BSON dumps to human-readable JSON for analysis
• Validate BSON encoding in custom MongoDB client implementations

Tips

• Paste BSON hex strings to see the decoded JSON structure
• Convert JSON to BSON hex for MongoDB wire protocol debugging
• Inspect ObjectId timestamps embedded in BSON documents

Fun Facts

• BSON (Binary JSON) was created by MongoDB Inc. in 2009 and supports data types JSON lacks, including Date, Binary, and ObjectId.
• A MongoDB ObjectId is exactly 12 bytes: 4 bytes for timestamp, 5 bytes for random value, and 3 bytes for an incrementing counter.
• BSON documents have a maximum size of 16 megabytes in MongoDB, a limit chosen to prevent any single document from consuming excessive RAM.

FAQ

What is BSON?

Binary JSON — MongoDB's storage format. Adds types that JSON lacks (ObjectId, Date, Binary, Decimal128) and encodes them in a compact binary layout. Every MongoDB document is stored as BSON.

When do I see BSON hex?

MongoDB wire protocol dumps, sharding replication logs, and driver debugging output. Rare in day-to-day work; essential when diagnosing low-level DB issues.

Does it preserve BSON-specific types in JSON?

Approximations: ObjectId as 24-char string, Date as ISO 8601 string, Binary as base64. The conversion is lossy for types that have no JSON equivalent — round-tripping back may differ.

Can I convert JSON to BSON?

Yes, bidirectional. Input JSON is parsed and serialized as BSON hex. Types with MongoDB semantics (ObjectId-style strings) are upgraded automatically.