The emergence of NFTs marks a watershed moment for true digital asset ownership. Unlike traditional digital assets, which require third-party validation to prove provenance, NFTs leverage blockchain technology to establish immutable ownership records.
At their core, NFTs are unique digital assets distinguished by their non-fungibility—each token carries distinct characteristics and cannot be exchanged on a one-to-one basis like cryptocurrencies (e.g., Bitcoin or Ethereum). This uniqueness has fueled their adoption in digital art, collectibles, virtual real estate, and beyond.
As the NFT ecosystem evolved, so did the need for diverse technical standards. While ERC-721 pioneered NFT creation, newer standards like ERC-721A and ERC-1155 emerged to address specific use cases, gas efficiency, and interoperability challenges.
This guide explores the three most widely used NFT standards:
- ERC-721 (the original NFT standard)
- ERC-721A (a gas-optimized upgrade)
- ERC-1155 (a hybrid fungible/non-fungible token standard)
Understanding ERC Token Standards
ERC (Ethereum Request for Comment) refers to technical standards proposed by the Ethereum community to improve network functionality. These standards define how tokens behave on the blockchain.
Key ERC Standards:
- ERC-20: The baseline for fungible tokens (e.g., utility tokens).
- ERC-721: The first non-fungible token (NFT) standard.
- ERC-721A: An optimized version of ERC-721 for batch minting.
- ERC-1155: A multi-token standard supporting both NFTs and semi-fungible tokens.
ERC-721: The Original NFT Standard
Features
- Uniqueness: Each token has a distinct ID, making it ideal for one-of-a-kind assets.
- Indivisibility: Cannot be split into smaller units (unlike ERC-20 tokens).
- Ownership Transparency: Transfer history and current holder are publicly verifiable on-chain.
- Metadata Support: Stores off-chain details (e.g., artwork descriptions, creator info).
Popular Use Cases
- Digital art (e.g., CryptoPunks)
- Collectibles (e.g., Bored Ape Yacht Club)
- Virtual real estate (Decentraland)
Limitations
- High Gas Fees: Each mint/transfer requires a separate transaction.
- No Batch Transfers: Inefficient for large collections.
- Scalability Issues: Struggles during Ethereum network congestion.
ERC-721A: The Gas-Efficient Upgrade
Developed by Chiru Labs (creators of Azuki NFTs), ERC-721A reduces costs for bulk operations.
Features
- Batch Minting: Mints multiple NFTs in one transaction.
- On-Demand Minting: No pre-minting required.
- Lower Gas Fees: Optimized for generative NFT collections (e.g., PFP projects).
Use Cases
- Profile-picture (PFP) collections (e.g., Azuki)
- In-game assets requiring frequent transfers
Limitations
- Higher Cost for Single Mints: Less efficient than ERC-721 for individual NFTs.
- No Semi-Fungible Support: Cannot transition between fungible and non-fungible states.
ERC-1155: The Multi-Token Standard
Introduced by Enjin, ERC-1155 supports both NFTs and fungible tokens in a single contract.
Features
- Batch Transfers: Move multiple token types in one transaction.
- Gas Efficiency: Up to 90% savings vs. ERC-721.
- Atomic Swaps: Ensures all-or-nothing execution for bundled operations.
- Backward Compatibility: Works with ERC-20 and ERC-721.
Use Cases
- Gaming (Axie Infinity)
- Dynamic marketplaces (OpenSea)
- Fractionalized assets
Limitations
- Complex Implementation: Harder to deploy than ERC-721.
- Limited Adoption: Fewer wallets/platforms support it natively.
Comparative Analysis
| Feature | ERC-721 | ERC-721A | ERC-1155 |
|------------------|-----------------|-----------------|-----------------|
| Batch Transfers | ❌ No | ✅ Yes | ✅ Yes |
| Gas Efficiency | ❌ High | ✅ Moderate | ✅ Excellent |
| Semi-Fungible | ❌ No | ❌ No | ✅ Yes |
| Use Cases | Art, Collectibles | PFPs, Games | Games, DeFi |
FAQ
Q1: Which standard is best for digital art?
👉 ERC-721 remains the top choice for unique artworks due to its simplicity and broad marketplace support.
Q2: Can ERC-1155 replace ERC-721?
👉 Not entirely. While ERC-1155 offers flexibility, ERC-721 is still preferred for purely non-fungible assets.
Q3: Why choose ERC-721A for PFP projects?
👉 Its gas-efficient batch minting significantly reduces costs for large collections.
Conclusion
Each NFT standard serves distinct purposes:
- ERC-721 for uniqueness.
- ERC-721A for cost-effective bulk operations.
- ERC-1155 for hybrid token economies.
As the space grows, developers will continue innovating to balance scalability, interoperability, and user experience.
👉 Explore NFT integration tools to leverage these standards for your project.