🆔 MongoDB ObjectId Generator – Generate & Decode ObjectIds Online

Use this free, browser-based MongoDB ObjectId Generator to create valid 12-byte ObjectIds instantly. Ideal for developers working with MongoDB, Mongoose, or BSON-based systems, this tool also helps decode the timestamp inside any ObjectId for debugging or data exploration.

Whether you're seeding a test database or validating creation times, this tool provides fast, private, and reliable generation of MongoDB ObjectIds.

📘 What Is a MongoDB ObjectId?

In MongoDB, every document is assigned a unique _id field. By default, this field is an ObjectId, which is a 12-byte value designed to ensure global uniqueness, sorting by creation time, and storage efficiency.

The structure of a MongoDB ObjectId:

Component	Size	Description
Timestamp	4 B	Unix timestamp (seconds since epoch)
Machine identifier	3 B	Usually based on the host’s MAC or hash
Process ID	2 B	The ID of the process creating the ObjectId
Counter	3 B	An incrementing counter for uniqueness

Example: 64a7086e40e1f7c9a3f9d875

Key Features:

• ✅ 100% unique (by design)
• 🕓 Includes creation timestamp
• 🧩 Optimized for sorting and indexing

🛠️ How the ObjectId Generator Works

This tool uses the same logic MongoDB does under the hood to construct ObjectIds:

• The timestamp is based on the current system time.
• Random values are used to simulate machine ID and process ID.
• The counter is initialized randomly to ensure uniqueness across sessions.

All generation is done locally in your browser—nothing is uploaded, logged, or stored.

Features:

• 🔒 Fully private and secure
• ⚡ Instant generation
• 🔍 Optional timestamp decoding
• 🧪 Works on all modern browsers

🚀 How to Use This Tool

1. Click the “Generate ObjectId” button to create a new 12-byte BSON ObjectId.
2. View the generated ID in hexadecimal format.
3. Optionally, decode the ObjectId to view the embedded creation timestamp.
4. Use the copy feature to grab the value for use in scripts or database operations.

You can also paste any existing ObjectId to decode and analyze its creation time.

🔍 Example

Generated ObjectId: 64a7086e40e1f7c9a3f9d875

Decoded Output:

• Timestamp: 2023-07-06T18:31:10+00:00
• Readable: Thursday, July 6, 2023, 18:31:10 (UTC)

This timestamp helps developers trace document creation or sort records chronologically—even without a createdAt field.

🧰 Common Use Cases

• 🛠️ Seeding test MongoDB databases with valid _id values
• 🔍 Investigating document creation times via ObjectId timestamps
• 🧪 Building test data for Mongoose models
• 📊 Sorting or filtering documents based on ID creation order
• 🧱 Creating mock ObjectIds for RESTful API endpoints

📎 Why Use This Tool?

• Works in-browser, no MongoDB installation needed
• Fast generation for prototyping or seeding
• Explore timestamp-encoded ObjectIds easily
• Save time during development and testing

This is particularly useful if you’re writing fixtures, mocking responses, or setting default IDs in unit tests.

📊 ObjectId vs UUID

Feature	ObjectId (MongoDB)	UUID (Universally Unique ID)
Length	12 bytes (24 hex chars)	16 bytes (32 hex chars)
Includes Time?	✅ Yes	❌ No
Sortable	✅ By creation time	❌ Not inherently
Use Case	MongoDB documents	Cross-system identity

If you need cross-database or cross-system uniqueness, consider using UUID Generator.

❓ Frequently Asked Questions (FAQ)

Can I reverse an ObjectId to get the creation date?

Yes! The first 4 bytes of the ObjectId represent the Unix timestamp. This tool can decode it for you automatically.

Does ObjectId guarantee global uniqueness?

Yes. Thanks to its combination of time, machine ID, process ID, and counter, ObjectId ensures uniqueness across distributed systems.

Is this safe to use in production?

Yes—for testing, scripting, and non-sensitive tasks. However, ObjectIds used in production databases should still be generated by the database or your backend ORM (e.g., Mongoose).

Can I generate multiple ObjectIds at once?

This tool currently supports one at a time. Bulk generation may be added in the future.

Can I decode ObjectIds created in the past?

Yes! Just paste any valid ObjectId to extract its embedded creation timestamp.

💡 Developer Tips

• If you need to simulate time-based data, generate ObjectIds with manual timestamps using libraries like bson-objectid (Node.js).
• You can use ObjectIds for sorting, as they reflect the order of insertion in MongoDB.
• Combine ObjectIds with createdAt fields for redundancy in production systems.

🔗 Related Tools

• UUID Generator
• Base64 Encoder
• SHA1 Generator
• MD5 Generator

📌 Final Thoughts

MongoDB ObjectIds are more than just unique identifiers—they’re compact, sortable, and timestamp-encoded. Whether you’re mocking data, decoding an _id, or seeding test databases, this ObjectId Generator is a fast and private solution to simplify your workflow.

🧭 Bookmark this tool for quick access during your backend development or database debugging sessions.