What is an IPFS CID?

Discover the essence of IPFS CIDs: The keys to decentralized data, content addressing, and a new internet paradigm.

What is an IPFS CID?

In the ever-evolving landscape of the internet, where data is vast and decentralized, technologies like IPFS (InterPlanetary File System) have emerged to revolutionize the way we store, share, and access information. At the core of IPFS lies a fundamental concept called the "CID" or Content Identifier. In this blog post, we will explore what IPFS is, its significance, and delve into the specifics of what an IPFS CID is and how it plays a pivotal role in the world of decentralized data.

Understanding IPFS

The Challenge of Traditional Web

The traditional web relies on a client-server architecture, where data is stored on central servers. This architecture has several drawbacks:

  1. Centralization: Data is controlled by a few entities, leading to potential censorship and control over information.
  2. Latency: Fetching data from distant servers can be slow, resulting in high latency.
  3. Fragility: Links can break if a server goes offline, leading to the infamous "404 Not Found" error.

IPFS was created to address these issues by providing a distributed and decentralized way to store and retrieve data.

What is IPFS?

IPFS, short for InterPlanetary File System, is a protocol and network designed to create a peer-to-peer method for storing and sharing hypermedia in a distributed file system. It was developed by Juan Benet and first released in 2015. IPFS takes inspiration from various technologies, including distributed file systems, the World Wide Web, and BitTorrent.

Key features of IPFS include:

  • Content-Addressing: Instead of addressing content by its location, like traditional URLs (Uniform Resource Locators), IPFS uses content-based addressing, ensuring data integrity and reducing reliance on centralized servers.
  • Decentralization: Data is distributed across a network of nodes, making it resistant to censorship and ensuring data availability even if some nodes go offline.
  • Efficient Content Sharing: IPFS employs a distributed hash table (DHT) and BitSwap, a protocol inspired by BitTorrent, to efficiently share content across the network.
  • Immutable Data: Once data is added to IPFS, it cannot be modified or deleted. This immutability ensures trustworthiness and data integrity.

Now that we have a foundational understanding of IPFS, let's dive into the heart of this technology: the IPFS CID.

IPFS CID: Content Identifier

What is an IPFS CID?

An IPFS CID, or Content Identifier, is a critical concept within the IPFS ecosystem. It is a unique identifier for any piece of content stored or referenced on IPFS. CIDs serve as the backbone of content-addressing, ensuring that data can be located and verified across the network. Here's a detailed breakdown of what an IPFS CID comprises:

  1. Multihash: The Multihash is a self-describing hash function used in CIDs. It defines which cryptographic hash function was used (e.g., SHA-256, SHA-3) and the length of the hash output.
  2. Multicodec: This part specifies the data format or encoding used for the content. It defines how to interpret the data once retrieved. Examples include "dag-pb" for Protocol Buffers and "raw" for raw binary data.
  3. Multibase: Multibase indicates how the CID is encoded. It can be represented in various encoding formats, such as base58, base64, or base32. Base58 encoding is commonly used.
  4. CID Version: CIDs can come in different versions, with each version having its own specification and use cases. The most widely used version is CIDv0.
  5. CID Prefix: The prefix is a combination of Multicodec and Multihash, indicating the type of content and the hash function used. It helps nodes quickly determine how to handle the CID.
  6. Content Identifier: This is the actual hash of the content, generated using the specified hash function. It uniquely identifies the content.

Example of an IPFS CID

Here's an example of what an IPFS CID might look like:


Let's break it down:

  • Multibase: In this example, it's encoded using base58.
  • CID Version: Typically CIDv0.
  • CID Prefix: Specifies the Multicodec and Multihash.
  • Content Identifier: The unique hash that identifies the content.

The Significance of IPFS CIDs

IPFS CIDs are the glue that holds the decentralized web together. They provide several key benefits:

  1. Content Addressing: CIDs enable content-based addressing, ensuring that you can locate and verify content independently of its location. This is crucial for a decentralized system like IPFS.
  2. Immutable Links: Because CIDs are generated from the content itself, they are immutable. Links to content remain valid as long as the content exists, regardless of where it's stored or who hosts it.
  3. Interoperability: CIDs are designed to be compatible with other content-addressable systems, fostering interoperability across various decentralized networks and protocols.
  4. Data Integrity: The cryptographic nature of CIDs ensures data integrity. Any change to the content results in a completely different CID, instantly revealing tampering attempts.


In the world of decentralized and distributed data storage, IPFS stands as a transformative technology, challenging the traditional client-server model. At the heart of IPFS lies the IPFS CID or Content Identifier, which plays a pivotal role in enabling content-based addressing, decentralization, and data integrity. CIDs are not merely strings of characters; they are the keys to a new internet paradigm, where data is owned by everyone and controlled by no one. As we continue to explore the potential of the InterPlanetary File System, understanding CIDs is essential to unlock the full power of this innovative technology.