Smart contracts run the decentralised web. But it’s shared standards, like ERC-20, ERC-721, and newer ones like ERC-4337 and ERC-4626 are the one that make the ecosystem work together.

Without these common rules, every wallet, dApp, or protocol would speak a different language. Standards are what turn isolated smart contracts into composable infrastructure.

In this blog, we break down the most important smart contract standards shaping Ethereum and Web3 in 2025, what they do, why they matter, and how they’re driving real adoption across DeFi, NFTs, identity, and cross-chain ecosystems.

Let’s get started.

What Are Smart Contract Standards?

Smart contract standards are predefined rules that smart contracts follow to behave predictably across the Ethereum ecosystem.

Think of them as shared protocols that developers and platforms agree on, so wallets, dApps, and block explorers can interact with contracts without needing custom logic for each one.

Most of these standards are published as Ethereum Improvement Proposals (EIPs). When they relate to smart contracts, they’re typically labelled as ERCs (Ethereum Request for Comments).

These include specifications for tokens, accounts, metadata, permissions, vaults, identity systems, and more.

The value of smart contract standards lies in what they unlock, like:

• Composability: dApps and protocols can plug into each other without rework.
• Security: Auditors and tools rely on familiar interfaces, reducing bugs.
• Interoperability: A token created on one contract works across wallets, bridges, and exchanges.
• Developer velocity: Builders don’t need to reinvent common patterns like token logic or access control.

Standards are not just convenience; they’re a coordination infrastructure. And in 2025, they’re the reason Ethereum and its rollups continue to scale, connect, and evolve as a cohesive ecosystem.

Let’s explore the ERCs that matter most today, and why they continue to be the backbone of Ethereum and beyond.

ERC Standards: The Backbone of Ethereum and Beyond

Smart contract standards are Ethereum’s native protocols for interoperability. But they don’t just make code reusable, they make ecosystems composable.

ERC standards define how tokens behave, how wallets interact, and how users trust what they’re signing.

Let’s break down the ERCs that truly matter today, with real-world adoption, current challenges, and what they mean for builders and teams.

ERC-20: The Standard That Powered DeFi and Still Does

ERC-20 defines how fungible tokens behave as interchangeable, uniform, and universally accepted across Ethereum’s ecosystem.

It remains the backbone of Ethereum’s token economy. From stablecoins and governance tokens to airdrops and liquidity incentives, nearly every tokenised asset on Ethereum and its rollups still relies on it.

The core spec hasn’t changed, but most major tokens now support EIP-2612 permit(), which allows approvals via off-chain signatures, removing the need for two on-chain transactions and saving gas. It’s now the default in modern DeFi flows.

Ecosystem adoption:

• Stablecoins & governance tokens: USDC, DAI, ARB, UNI all rely on ERC-20.
• Protocols using permit(): Aave, Uniswap, Compound, DAI, and most Base-native apps now support signature-based approvals.
• Layer 2 support: ERC-20 tokens are fully composable across Arbitrum, Optimism, and Base.

One limitation: ERC-20 lacks pre-transfer validation hooks. This means if a user sends tokens to a contract that can’t handle them, the tokens may be permanently lost, an issue still seen in some staking contracts and bridges.

Today, it is still the most integrated, audited, and indexable standard in the Ethereum ecosystem. For most projects, ERC-20 is not just good enough; it’s the expected norm.

ERC-721: How Ethereum Gave Assets a Soul

ERC-721 defines how non-fungible tokens (NFTs) behave. Each token is unique, indivisible, and linked to custom metadata.

It introduced the idea of programmable ownership, where digital assets could carry identity, provenance, and value beyond just a token balance.

While it started with digital art, ERC-721 now powers a growing range of use cases, from identity systems and social usernames to access credentials and DAO badges.

The core spec defines functions like ownerOf, tokenURI, and safeTransferFrom, enabling universal support across wallets, marketplaces, and applications.

Ecosystem adoption:

• On-chain identity: Farcaster’s fnames (e.g. alice) are ERC-721 tokens.
• Publishing & editions: Platforms like Zora and Mirror mint open editions, articles, and collectables using ERC-721.
• Gaming & ticketing: In-game items and event passes use ERC-721 for verifiable uniqueness and ownership history.
• Infrastructure support: Fully supported across wallets like Rainbow, Coinbase, MetaMask, and marketplaces like OpenSea, Zora, and Blur.

ERC-721 does not support batch minting or multi-token structures. For applications needing large-scale issuance, like gaming or generative art, it can become gas-inefficient and operationally fragmented compared to ERC-1155.

It remains the most trusted standard for unique digital assets. It laid the foundation for Web3-native identity, expression, and community ownership and continues to define the interface between people and their digital presence.

ERC-1155: The Standard for Scalable Token Systems

ERC-1155 blends the capabilities of ERC-20 and ERC-721 into a single, flexible contract.

It allows a single smart contract to manage both fungible and non-fungible tokens, making it ideal for applications that need to handle multiple token types efficiently.

Designed for batch operations and shared metadata, ERC-1155 significantly reduces gas costs and simplifies contract logic, especially in use cases like gaming, collectables, and edition-based art.

Ecosystem adoption:

• Gaming & metaverse: The Sandbox mints LAND parcels, weapons, and in-game assets using ERC-1155.
• Asset-heavy games: Enjin and Immutable rely on ERC-1155 to support large-scale, gas-efficient token operations.
• Minting platforms: Zora V3 supports ERC-1155 for edition drops and multi-token formats.
• Wallet & L2 support: Fully compatible with Arbitrum, Optimism, Polygon, and Base. Major wallets like MetaMask and Coinbase Wallet now support ERC-1155 token display and transfer.

Batch minting and transferring of multiple token IDs in a single transaction can save up to 90% in gas costs compared to separate ERC-721 or ERC-20 calls.

Today, they have become the go-to infrastructure for high-throughput, multi-asset applications.

Whether you’re building a game with thousands of items or launching large-scale collectable drops, it offers the scalability that ERC-20 and ERC-721 alone can’t match.

ERC-4626: Turning Yield into Infrastructure

ERC-4626 is the tokenised vault standard that defines how deposits, withdrawals, and yield accounting should work across DeFi protocols.

It brings uniformity to interest-bearing tokens, allowing vaults to expose a predictable and composable interface.

Instead of each platform designing its wrapper for yield-bearing assets, ERC-4626 provides a single, auditable structure that works across aggregators, frontends, and strategy layers.

Ecosystem adoption:

• Yearn Finance: Fully migrated all vaults to ERC-4626 by early 2024, simplifying integrations across the ecosystem.
• Balancer: Uses ERC-4626 wrappers in its boosted pools to streamline yield strategies.
• Instadapp & DeFiLlama: Leverage ERC-4626 vaults to display cross-protocol yield in a standardised way across dashboards and analytics.

Before ERC-4626, each vault system, like cTokens, required separate adapters. Now, a single integration works across any protocol using the 4626 interface.

ERC-4626 turns DeFi yield from fragmented infrastructure into a composable layer.

It reduces developer overhead, increases auditability, and makes strategy design portable across protocols.

Today, it is the standard that drives deeper integrations between vaults, aggregators, and on-chain asset management systems.

ERC-4337: Smart Wallets Without Permission

ERC-4337 brings account abstraction to Ethereum without requiring changes to the base protocol.

It transforms externally owned accounts (EOAs) into programmable smart contract wallets, enabling features like social recovery, session keys, gas sponsorship, and custom authentication.

By decoupling wallets from rigid signature and nonce logic, ERC-4337 allows developers to design more intuitive, secure, and recoverable wallet experiences.

Ecosystem adoption:

• Safe: Implements ERC-4337-compatible modules, enabling smart wallets with pluggable logic.
• Biconomy, Pimlico, StackUp: Provide SDKs and infrastructure for account abstraction, powering wallet UX across Web3 apps.
• Lens Protocol: Uses smart accounts for on-chain subscriptions, content monetisation, and delegated social actions.

As of mid-2025, over 7.3 million smart accounts have been deployed using the ERC-4337 infrastructure. On Base and Optimism, more than 60% of new wallets are now smart accounts by default.

Bundlers, paymasters, and middleware services are now live across major L2s, enabling seamless onboarding, gasless transactions, and programmable account flows.

ERC-4337 is solving one of Web3’s longest-standing UX problems, i.e. onboarding.

By allowing users to recover accounts via guardians, log in with passkeys, or pay gas in any token, it bridges the usability gap between crypto-native and mainstream users.

In 2025, ERC-4337 is more than a wallet upgrade; it’s a new baseline for what users expect from Web3.

ERC-6900 & ERC-7579: Modular Smart Accounts Are the Next UX Layer

These standards extend the ERC-4337 smart account model by defining a modular framework for extending wallet functionality.

Think of smart accounts as the operating system; ERC-6900 and 7579 are how you install apps.

• ERC-6900 defines how modules, e.g., guardians, spending limits, and 2FA, can plug into a smart account using standard interfaces.
• ERC-7579 specifies a registry-based method for modules and ensures interoperability across wallet providers.

Smart wallets are not just about social recovery anymore. Users want custom logic, i.e. auto-investing, delegated access, usage limits, all composable and permissionless.

Real-world usage:

• Safe’s “Core SDK” integrates ERC-7579 to support modular smart account extensions.
• Biconomy’s B-Wallet and ZeroDev offer developer-friendly toolkits for creating module-based wallets.
• Sponsorship modules, Rate-limiters, Session key managers, and custom auth are all being deployed on top of these standards.

Standardisation here is a game-changer: instead of building a custom wallet stack, developers can compose off-the-shelf modules like Legos.

ERC-6900/7579 brings app-store level extensibility to wallets. For any serious dApp looking to offer a smooth UX, this is becoming the default approach.

ERC-1400: The First Step Toward Tokenised Compliance

ERC-1400 was designed to bring regulatory compliance to Ethereum tokens. It enables:

• Transfer restrictions (e.g., KYC only),
• Partitioned ownership (e.g., different share classes),
• Off-chain document linking (e.g., prospectuses).

As traditional finance continues to explore tokenised assets like equity, real estate, and debt, compliance-first token standards are critical.

Real-world usage:

• Security token platforms: Used by early security token platforms like Polymath, Securitise, and Tokeny to issue regulated assets.
• Institutional pilots: Served as the basis for EU sandbox initiatives exploring tokenised shares and bonds under MiFID II and MiCA-aligned guidelines.

Key features:

• Functions like canTransfer() and validateTransfer() let contracts enforce legal rules on-chain.
• Offers modularity via sub-standards: ERC-1410 (partitions), 1594 (transfer logic), 1643 (document metadata).

Early challenge was that adoption was limited in its early years due to technical overhead and unclear regulatory pathways before 2023. As a result, few mainstream DeFi platforms implemented it.

In 2025, ERC-1400 is regaining relevance as institutions look for on-chain assets with programmable compliance.

It laid the architectural foundation that newer standards like ERC-3643 are now building on and remains a trusted choice where transfer control and auditability are non-negotiable.

ERC-3643: Identity-Bound Tokens for Regulated Assets

ERC-3643 (formerly known as T-REX) is a modern, compliance-first token standard designed to link token ownership to verified on-chain identities.

It brings institutional-grade control to asset issuance, ensuring that only authorised wallets that meet regulatory or jurisdictional requirements can hold or transfer the token.

Built with modularity in mind, ERC-3643 integrates seamlessly with identity registries, KYC providers, and revocation systems, offering granular control over investor eligibility.

Ecosystem adoption:

• Tokeny: Uses ERC-3643 to issue regulated tokens across Europe, including real estate and private market funds.
• Société Générale’s Forge: Piloted ERC-3643 in tokenising digital bonds and structured financial products.
• Use cases: Tokenised funds, carbon credits, real estate assets, and institution-grade digital securities.

How it works:

• Only wallets registered to a verified identity can hold ERC-3643 tokens.
• Transfers are automatically validated to ensure the receiving address is whitelisted or compliant.
• Identity checks and permissions are handled via on-chain registries, allowing issuers to maintain dynamic access control without compromising on-chain composability.

ERC-3643 fits right into what regulators now demand. With MiCA and AMLD5 in play, it gives asset issuers a ready-made toolkit to stay compliant without reinventing how tokens work.

In 2025, ERC-3643 is emerging as the go-to standard for tokenising real-world assets.

For financial institutions, enterprises, and protocol teams looking to build in regulated environments, it offers the most advanced toolkit for issuing, managing, and restricting tokenised assets, without sacrificing Ethereum-native interoperability.

ERC-5192: Soulbound Tokens, Done Right

ERC-5192 is a minimalist extension of ERC-721 that introduces a locked status signalling that a token is non-transferable.

It’s designed for NFTs that represent reputation, identity, or credentials, where transferability isn’t just unnecessary, it’s undesirable.

As Web3 identity systems mature, ERC-5192 provides the base layer for soulbound tokens (SBTs): tokens that prove something about you, rather than something you own.

Ecosystem adoption:

• Gitcoin Passport: Issues ERC-5192-based badges for Sybil resistance and proof of on-chain contribution.
• Sismo, TalentLayer, Optimism: Explore SBTs for privacy-preserving credentials, work history, and role-based access.
• DAOs: Use non-transferable tokens to recognise contributors, manage access tiers, and encode voting power in non-speculative ways.

How it works:

• ERC-5192 extends ERC-721 by adding a locked flag.
• If a token is locked, wallets and dApps can easily detect that it cannot be transferred.
• This avoids accidental transfers and ensures clarity in UX, auditability, and design.

As DAOs, public goods ecosystems, and identity networks grow, Web3 needs non-financial signals like achievements, verifications, and credentials that stay with the user.

ERC-5192 offers a lightweight, standard-compliant way to encode that.

In 2025, ERC-5192 is a quiet enabler of Web3-native reputation. It’s what turns degrees, DAO roles, certifications, or verified statuses into on-chain primitives, without letting them be flipped or traded like assets.

Why Standards Matter: Beyond Code Compatibility

Smart contract standards do more than define how code behaves; they shape how ecosystems grow, how users interact, and how protocols build trust.

Today, their role is even more critical. As Ethereum expands across rollups, verticals, and user types, standards ensure that builders don’t have to reinvent basic infrastructure every time.

Let’s explore how each of these is shaped by the standards Ethereum runs on and why that makes them foundational to Ethereum’s next decade.

Composability That Compounds

Standards like ERC-20, ERC-4626, and ERC-4337 enable true plug-and-play development. Composability isn’t just technical, it’s strategic.

Teams that adopt shared standards benefit from faster integrations, shared tooling, and network effects.

Without ERC-4626, Yearn vaults would require custom adapters. With it, any aggregator can plug in directly, with no special code.

Ecosystem-Wide UX Consistency

For users, standards ensure that tokens behave predictably and wallets “just work.” ERC-4337 is a great example; it abstracts away gas, signatures, and recovery pain, enabling wallet flows that resemble Web2 onboarding.

Standards also enable wallet-layer UX upgrades like:

• Gasless approvals via EIP-2612 (permit)
• Social recovery and biometrics via ERC-4337
• In-wallet dApp interactions using standardised calls

When your token or contract speaks a standard interface, it unlocks instant compatibility across MetaMask, Safe, Coinbase Wallet, and more.

Security, Auditing, and Tooling

Auditors and static analysers rely on standard interfaces to reason about contract behaviour. Standards like ERC-20 and ERC-721 have hardened over time, battle-tested by billions in TVL.

Tooling platforms like Tenderly, OpenZeppelin Defender, and Dune Analytics build support once for a standard and extend it across every compliant contract.

Without standards, every new contract is a black box. With standards, it's instantly indexable, testable, and debuggable.

Bridging Across Chains and Protocols

As Ethereum scales through rollups, apps span multiple chains. Standards like ERC-7683 (intents) and ERC-7786 (cross-chain messaging) are now defining how dApps speak to each other across chains, without relying on centralised bridges or manual wrappers.

Just like ERC-20 made tokens portable across dApps, these new standards are making logic portable across L2s.

Compliance and Regulation-Readiness

In RWA and institutional finance, standards like ERC-1400 and ERC-3643 bring legal and regulatory logic on-chain, ensuring that only verified, eligible wallets can hold certain assets.

Rather than building custom KYC logic, issuers can rely on standardised compliance frameworks baked into the token itself.

This is especially important as jurisdictions like the EU roll out frameworks like MiCA, which require traceability and whitelisting by design.

Ethereum’s real strength lies not in its speed or cost, but in how reliably developers can build on shared primitives. ERCs make that possible. They’re the infrastructure beneath the infrastructure.

Beyond ERCs: Standards in Other Ecosystems

Ethereum’s ERCs set the gold standard for smart contract interoperability. But as the multi-chain world matures, other ecosystems are now defining their own native standards, tailored to their architecture, consensus models, and use cases.

Here’s how leading ecosystems are approaching smart contract and token standards in 2025:

Cosmos: Modules, Messages, and the IBC Standard

Cosmos chains don’t rely on token standards like ERCs. Instead, they use Cosmos SDK modules for core functionality (banking, staking, governance), and communicate using IBC (Inter-Blockchain Communication).

Key standards:

• ICS-20: The IBC equivalent of ERC-20, enabling fungible token transfers across Cosmos chains.
• ICS-721: Experimental standard for NFTs over IBC.
• ICS-28: For interchain accounts (remote contract execution).

IBC now connects over 100+ chains (Osmosis, Celestia, dYdX, Neutron), allowing assets and logic to flow across sovereign blockchains with finality and composability.

While Cosmos lacks a formal “ERC” structure, its modular, chain-level standards offer higher customisation, ideal for app-specific chains.

Solana: Program Constraints and Token-2022

Solana uses programs (smart contracts) with strict runtime constraints. Token behaviour is defined by the SPL token program, its counterpart to ERC-20.

Token-2022 Upgrades:

• Transfer hooks
• Confidential transfers
• Permanent delegation
• Interest-bearing tokens

Token-2022 is now the standard for new tokens on Solana, offering features that ERC-20 lacked natively, like fee logic, clawbacks, and metadata enforcement.

NFT royalties, institutional stablecoins, and Solana-native identity protocols now rely on Token-2022’s feature-rich design.

Solana’s standards are contract-enforced at runtime, not interface-driven like ERCs. This enables high performance, but limits composability with other chains.

Polkadot: WASM Contracts and Metadata Schemas

Polkadot’s smart contract parachains like Astar and Moonbeam use ink! (Rust-based) and WASM (WebAssembly) as the contract VM.

Token standards:

• PSP-22: Polkadot’s fungible token standard (equivalent to ERC-20).
• PSP-34: NFT standard (equivalent to ERC-721).
• PSP-37: Multi-token standard (like ERC-1155).

Substrate-based chains allow developers to define contract metadata with enforced interfaces, while enjoying low-level optimisations via WASM.

Cross-chain composability between parachains is being explored using XCM v3, Polkadot’s cross-chain message standard (akin to IBC).

Starknet and Cairo: New Language, New Primitives

Starknet smart contracts are written in Cairo, a custom language optimised for zero-knowledge proofs.

Current efforts:

• Developing Cairo equivalents of ERC-20 and ERC-721, with focus on ZK-friendly design.
• Supporting account abstraction and permissioned logic natively at the protocol level.

Starknet’s standards focus less on interoperability with EVM and more on cryptographic scalability and privacy. However, ERC-style interfaces are still emerging via projects like Dojo and Madara.

Avalanche, Near, and Sui: Diverse Approaches

• Avalanche (C-Chain): Fully EVM-compatible; ERCs work natively.
• Near Protocol: Uses WASM and Rust; developing NEP standards, e.g., NEP-141 for fungible tokens.
• Sui: Focused on Move-based asset programming. Defines standards for object ownership, composability, and access control via the “object capability” model, not token balances.

Each ecosystem is converging on standards, but most are evolving toward use-case-specific models, like gaming, NFTs, and privacy.

What This Means for Ethereum and ERCs

ERCs remain the most widely adopted and production-tested standards in Web3. They’re the backbone of Ethereum’s composability and continue to evolve alongside the ecosystem.

But as infrastructure becomes increasingly multi-chain, the next challenge isn’t just defining new ERCs, it’s making them interoperable across ecosystems.

Key directions shaping the future:

• Cross-chain ERC mirrors: Standards like ERC-20 are now being reflected on non-EVM chains using bridges or mirrored representations (e.g. via IBC-compatible wrappers).
• Metadata and messaging extensions: Proposals like ERC-7683 aim to standardise how cross-chain protocols pass messages, metadata, and intents between networks.
• Unified indexing and bridging protocols: There’s growing interest in cross-chain indexing standards and token registries that support both EVM and non-EVM environments.

The next phase of ERC evolution isn’t just about better standards, it’s about interconnected standards that can span rollups, appchains, and even non-EVM ecosystems.

Standards Are Infrastructure

Behind every token, vault, wallet, and DAO lies a standard, a quiet contract that everyone agrees to follow. These aren’t just developer conveniences. They’re the rules that make the Ethereum ecosystem interoperable, composable, and verifiable.

In 2025, ERCs are doing more than enabling tokens:

• Powering account abstraction, turning wallets into programmable accounts.
• Defining vault structures, enabling plug-and-play DeFi.
• Standardising identity and credentials, giving rise to on-chain reputation systems.
• Preparing Ethereum for a multi-chain world, where logic and assets can move across rollups and ecosystems.

As the ecosystem evolves, so do the standards. From ERC-20 to ERC-4337 and beyond, each step forward reflects a broader shift, from raw functionality to usability, composability, and trust.

For builders, choosing the right standard is no longer just a technical decision. It’s a strategic one. It affects who can integrate with you, how fast you can scale, and how secure your code is on day one.

For protocol teams, picking the right standard is more than code; it’s about integrations, speed, security, and future-proofing your stack.

As Ethereum evolves, so must your architecture. Choose standards like you’d choose infrastructure: for the long haul.