ZKsync Sepolia RPC Endpoints & API | OnFinality

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Connect to ZKsync Sepolia in seconds with OnFinality RPC endpoints, request analytics, scalable rate limits, and 99.99% uptime for production Web3 apps.

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Create RPC Endpoint

ZKsync Sepolia RPC Endpoint

The below example uses the public API endpoint*. This endpoint is only suitable for testing. To avoid rate limiting and service interruption, sign up now to get your own API key.

* The public endpoint is rate limited

RPC API Service

RPC API Features

ArchiveTraceFull

RPC Regions

N.VirginiaHong Kong

ZKsync Sepolia RPC Endpoints

ZKsync Sepolia is a testnet for the ZKsync Era, a zkEVM Layer 2 scaling solution for Ethereum. It provides a low-cost, high-throughput environment for developers to test smart contracts, dApps, and integrations before deploying to mainnet. The network uses zero-knowledge proofs for security and offers native account abstraction.

Why Use OnFinality for ZKsync Sepolia RPC?

OnFinality provides managed API endpoints for ZKsync Sepolia, giving developers reliable access without the overhead of running their own node. Key benefits include:

Authenticated Access: Private endpoints with usage analytics and rate limits.
Archive & Trace Support: Access historical state and transaction traces for debugging.
Multiple Regions: Endpoints available in N. Virginia and Hong Kong for low latency.
Scalable Plans: From shared API to dedicated nodes for higher throughput.

Common Use Cases

Smart Contract Testing: Deploy and interact with contracts in a safe environment.
QA & Staging: Validate releases before mainnet deployment.
Wallet Integration: Test wallet connections and transactions.
Backend Validation: Verify off-chain logic against on-chain data.

How to Connect

Create an OnFinality account.
Select ZKsync Sepolia from the network list.
Create an API endpoint (HTTP or WebSocket).
Use the endpoint URL in your dApp or script.
Monitor usage via the dashboard.

Network Details

Chain ID: 300 (0x12c)
Currency: ETH
RPC Protocol: EVM JSON-RPC
Transport: HTTP, WebSocket
Explorer: sepolia.explorer.zksync.io

Public vs OnFinality RPC

Public endpoints are suitable for lightweight testing but often have rate limits and no observability. OnFinality endpoints provide authenticated access, request analytics, and a clear path to production-grade infrastructure.