Walrus is a decentralized storage and data availability protocol built on the Sui blockchain, designed to handle large files efficiently and cost-effectively while providing high reliability, decentralization, and integration with smart contracts. Unlike many storage systems that replicate entire files across many machines, Walrus uses modern erasure coding techniques so that files — referred to as “blobs” — are encoded into many smaller fragments (called slivers) and distributed across a network of independent storage nodes. A subset of these fragments is sufficient to reconstruct the original file even if many nodes go offline or behave maliciously, allowing Walrus to maintain high fault tolerance with a low replication factor compared with blockchain systems that fully replicate data.
Walrus aims to solve a fundamental challenge in decentralized systems: storing large unstructured data (such as videos, images, large datasets, web applications, or historical blockchain state) in a way that is cheaper, more resilient, and more programmable than storing that data directly on a base layer blockchain. In this architecture, the Sui blockchain plays the role of the coordination and metadata layer: it tracks blob objects, manages payments, verifies availability proofs, and governs the protocol, while the actual data fragments are held off-chain across a distributed set of storage nodes.
At the heart of Walrus’s architecture is a sophisticated encoding scheme often referenced as Red Stuff (Walrus’s custom erasure-coding algorithm). When a user uploads a blob, Walrus breaks it into fixed-size chunks and then creates encoded fragments that are distributed across storage nodes. Only a fraction of these fragments is needed to rebuild the original data, allowing the system to use around 4x–5x the original file size in storage space rather than the very high multiples often seen in full-replication blockchains. This makes storing gigabytes or even larger amounts of data both practical and affordable within a decentralized framework.
Because all blobs have associated proofs of availability, third parties — or even smart contracts — can efficiently verify that the data is still stored and retrievable without downloading the full blob. That capability is essential for protocols that require data availability guarantees, such as Layer 2 rollups, decentralized websites, decentralized applications (dApps), NFT media hosting, AI model storage, and decentralized archives. In some cases, decentralized websites (sometimes called Walrus Sites) can be fully hosted by storing front-end resources — CSS, HTML, JavaScript, media — on Walrus and serving them via traditional HTTP caches and content delivery infrastructures, all while maintaining a decentralized data backbone.
Walrus is also tightly integrated with the Sui blockchain. Every blob stored in Walrus is tied to one or more Sui “objects,” and users interact with the system through Sui accounts and transactions. Sui not only handles payments and metadata registration but also allows smart contracts to extend storage durations, attest availability, or perform protocol governance tasks. This deep integration lets blobs be referenced and managed the same way on-chain assets are, which creates powerful composability with other Sui-based protocols and applications.
A key component of the economic and incentive structure that secures Walrus is its native token, WAL. WAL serves multiple core functions in the network:
Storage payments: Users pay WAL to upload, store, and maintain data. These payments are used to compensate storage node operators and stakers for their service.
Staking and delegation: Storage node operators must stake WAL to participate and earn rewards, and token holders can delegate WAL to them. Delegation increases network security and allows delegators to share in node rewards.
Governance: WAL holders have governance rights, enabling them to vote on protocol parameters such as pricing rules, reward schedules, and slashing conditions.
Reward distribution: WAL is distributed periodically to storage nodes and their delegators based on uptime, availability proofs, and performance criteria during defined epochs.
The maximum token supply for WAL is 5 billion tokens, with allocations that have been strategically distributed for ecosystem development, community incentives, and long-term sustainability. For example, a significant portion of the supply is allocated to a community reserve designed to support protocol growth well into the future, while smaller portions are reserved for user drops and early incentives.
Walrus uses a delegated proof-of-stake (DPoS) model, where nodes are selected to form a storage committee based on the amount of WAL staked on them. Each “epoch” (a defined period during protocol operation) involves reconfiguring which storage nodes are active, assigning shards, and distributing WAL rewards. Epochs help the network adapt to node churn and ensure that data availability remains robust even when nodes join or leave the network.
The security model built into Walrus relies on the assumption that the majority of storage nodes are honest and available. The use of erasure coding and Byzantine fault-tolerant mechanisms ensures that data remains recoverable even if a significant fraction of nodes go offline or behave maliciously. Within each epoch, the protocol tolerates up to one-third of storage shards being controlled by faulty or malicious nodes without compromising data retrievability.
In practice, Walrus’s design emphasizes cost efficiency without sacrificing reliability. By spreading and distributing encoded fragments instead of fully replicating entire files across all nodes, Walrus achieves significantly lower storage overhead compared with storing blobs directly on the base layer blockchain. This makes the protocol suitable for very large datasets: whether it be media for NFTs, decentralized applications, blockchain history, or even massive AI training datasets.
Walrus’s architecture also anticipates future expansion and innovation. Beyond simple data storage and retrieval, developers and enterprises are exploring how Walrus can serve as a decentralized data availability layer for other blockchain ecosystems, host AI models and training data securely, enable subscription-based encrypted media delivery models, and support fully decentralized web experiences where front-end assets are stored and served by Walrus nodes.
The ecosystem has attracted substantial investment and participation from major firms within the crypto space. In early 2025 the Walrus Foundation raised around $140 million in a private funding round with participation from top investors including Andreessen Horowitz (a16z Crypto), Electric Capital, Franklin Templeton Digital Assets, and others. These funds aim to accelerate development, expand protocol capabilities, and catalyze adoption of decentralized storage infrastructure.
Since its mainnet launch in 2025, Walrus has rapidly developed its network and tooling, including command-line tools, SDKs for popular programming languages, and greater integration into developer workflows. The protocol supports traditional web2-style HTTP access alongside Web3 usage, so developers can build hybrid systems that take advantage of decentralized storage while being compatible with existing technologies.
Walrus’s approach to decentralized storage reflects a broader shift in blockchain infrastructure: moving beyond financial transactions and simple token transfers to supporting rich, data-intensive applications in a secure, decentralized manner. Its combination of blockchain coordination, distributed storage, erasure coding, smart contract integration, and a comprehensive token economy positions it as a new kind of infrastructure layer that supports both data storage and decentralized applications in an increasingly complex decentralized ecosystem.
In summary, Walrus and the WAL token together create a decentralized ecosystem where large amounts of data can be stored, verified, and accessed across a distributed network while incentivizing honest participation, enabling governance, and integrating seamlessly with blockchain applications — all with cost efficiency and decentralization at its core.
