MongoDB ObjectID Generator

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ObjectID Decoder

ObjectID Structure

MongoDB ObjectIDs are 12-byte identifiers consisting of:

  • Timestamp: 4 bytes (creation time)
  • Random Value: 5 bytes (unique per machine/process)
  • Counter: 3 bytes (incremental)

Total: 24 hexadecimal characters

Use Cases
  • πŸ—„οΈ MongoDB Documents - Primary key generation
  • πŸ”— API Resources - Unique resource identifiers
  • πŸ“Š Distributed Systems - Cross-service references
  • πŸ”„ Data Migration - Preserving document relationships
  • πŸ“ Testing - Mock data generation
ObjectID Properties
  • βœ… Globally Unique
  • βœ… Timestamp Embedded
  • βœ… Sortable by Creation
  • βœ… No Central Coordination
  • βœ… URL Safe

MongoDB ObjectID Generator for Database Development

Generate valid MongoDB ObjectIDs for database development, API testing, and data modeling. Our tool creates authentic ObjectIDs that follow MongoDB's specification and can be used in production applications.

What are MongoDB ObjectIDs?

ObjectIDs are 12-byte identifiers used as the default primary key for MongoDB documents. They consist of a timestamp, a random value unique to the machine and process, and an incrementing counter, ensuring global uniqueness without central coordination.

ObjectID Benefits

  • Guaranteed global uniqueness across distributed systems
  • Embedded timestamp enables chronological sorting
  • No need for centralized ID generation
  • URL-safe hexadecimal representation
  • Compact 12-byte storage footprint
  • Can extract creation time from the ID

Development Use Cases

  • MongoDB document _id field generation
  • RESTful API resource identifier creation
  • Microservice communication and data referencing
  • Database seeding and test data generation
  • Data migration and ETL processes
  • Distributed system coordination

ObjectID Questions

MongoDB's default primary key β€” 12 bytes containing a timestamp, random value, and counter. Globally unique without coordination, and you can extract when it was created.

Yes, the first 4 bytes are a Unix timestamp. Paste any ObjectID here and the decoder will show you when it was created. No need for a separate createdAt field.

For MongoDB, stick with ObjectID. It's smaller (12 vs 16 bytes), built-in, and time-sortable. Only use UUID if you need cross-system compatibility.

Roughly. Same second + same machine = sequential. Different machines or different seconds = generally ordered but not strictly sequential.