Adding a second or third blockchain to an NFT product is an engineering project with predictable phases: pick the chain for a concrete reason, abstract chain-specific code, deploy and index, fix wallet flows, then operate it. Skipping the abstraction step is what turns chain number three into a rewrite.
This page assumes you already run an NFT app on one chain. If you are choosing licensed software that ships with several chains, see the white-label multichain platform guide instead.
Phase 1: Decide which chain and why
Write down the specific reason for the new chain. "Partner X's wallet only supports Base." "Our game items cost more in gas than they sell for on Ethereum." "A creator community we want lives on Solana." If the reason is general reach, test it with a small pilot first.
Then classify the chain:
- Another EVM chain (an Ethereum L2, Polygon PoS, BNB Smart Chain, Avalanche C-Chain). Contracts and wallet code mostly carry over.
- A non-EVM chain (Solana, Flow, Tezos, Cardano). Treat it as a new integration with its own contracts, SDKs and indexer.
For low-fee options on Ethereum's security model, see NFT layer 2 development.
Phase 2: Refactor for chain abstraction
Before deploying anything, find every place your code assumes a single chain: hard-coded chain IDs, RPC URLs, contract addresses, block explorer links, native token symbols, confirmation counts, and database tables without a chain column. Replace them with a chain registry, a config object per chain that the rest of the app reads.
In the database, the primary key for a token becomes chain ID plus contract address plus token ID. Collections, listings, sales and user wallets all need a chain field. This migration is the most tedious part of the project and the one that pays off with every later chain.
Phase 3: Contracts and deployment
On EVM chains, redeploy the same audited bytecode. Deterministic deployment with CREATE2 can give contracts the same address on each chain, which simplifies configuration and user trust. Check chain-specific differences before assuming parity: some L2s price calldata differently, some chains have different precompiles or opcode support, and block timestamps behave differently on rollups.
Decide how supply works across chains. If a collection exists on two chains, either split the allocation explicitly or use a bridge that locks on one side and mints on the other. Never let two independent contracts mint the "same" token IDs, or you create duplicates that collectors will rightly object to.
On non-EVM chains, you will write or adopt different programs, for example Metaplex standards on Solana or Cadence contracts on Flow.
Phase 4: Indexing and data
Each chain needs ingestion, backfill, reorg handling and metadata fetching. Set confirmation thresholds per chain, because finality differs between Ethereum, optimistic rollups, ZK rollups, Polygon PoS and Solana. Many teams buy an NFT data API for well-supported chains and run their own indexer only where coverage is thin.
Phase 5: Wallets and UX
- Detect the user's current network and prompt a switch before any transaction, not after a failure.
- Show the chain clearly on every item, listing and transaction.
- Handle gas in the right native token per chain, or sponsor it.
- Link several addresses to one profile so a user's holdings appear together.
- Display correct token names. Polygon's gas token is POL since the 2024 migration from MATIC; BNB Smart Chain uses BNB.
Phase 6: Testing and launch
- Run the full contract test suite against a fork of the new chain.
- Deploy to the chain's testnet and run end-to-end flows: mint, list, buy, cancel, transfer, royalty payout.
- Load-test the new indexer with a backfill and a burst of events.
- Get a short security review of any contract or config differences from the audited version.
- Launch with a limited set of collections, then open up.
Phase 7: Operating several chains
Monitor indexer lag, RPC error rates and failed transactions per chain. Subscribe to each chain's upgrade announcements, since hard forks and sequencer changes can break assumptions. Review volume against cost quarterly. Dropping a chain that adds support burden without trades is a legitimate decision; announce it early and keep read-only access to existing items.
If you later want assets or purchases to move between chains, that is a separate cross-chain project with bridge risk, covered in the cross-chain NFT marketplace guide.
Frequently asked questions
How long does adding a new EVM chain take?
If the codebase already abstracts chains, often one to three weeks including testing. If chain assumptions are hard-coded everywhere, the first additional chain can take a couple of months.
Do I need a new audit for each chain?
Not for identical bytecode on equivalent EVM chains, though a review of chain-specific behavior is wise. Any code change or non-EVM contract needs its own audit.
Can users move their NFTs between chains?
Only through a bridge, which wraps the token on the destination chain. Native multichain support does not move assets by itself.
Should the same collection exist on several chains?
Usually not. It confuses collectors and complicates supply. Keep each collection on one chain unless there is a strong reason.