Resolving the Internal JSON-RPC Error in MetaMask: A Complete Troubleshooting Guide

Encountering an “Internal JSON-RPC Error” message in MetaMask can be frustrating, but most cases are resolvable with systematic troubleshooting. This error typically occurs when your wallet cannot properly communicate with the blockchain network’s RPC endpoint. Here’s how to diagnose and fix the issue.

Start with the Endpoint Provider

The most common culprit behind the Internal JSON-RPC Error is an unstable or incorrect RPC endpoint. Your MetaMask wallet communicates with the blockchain through this endpoint, so any misconfiguration here will cause the error.

Navigate to your MetaMask settings and locate the problematic network. Select it and look for the “New RPC URL” field. Try switching to an alternative RPC endpoint. Many networks have multiple public endpoints available—if your current provider is experiencing downtime or rate-limiting, switching providers often resolves the issue immediately.

Verify Your Network Configuration

Before assuming there’s a deeper problem, ensure the network itself is correctly added to MetaMask. Visit MetaMask’s official documentation for the proper setup instructions for your specific blockchain (Ethereum, BNB Chain, Polygon, etc.).

Double-check that the Chain ID, Network Name, and Currency Symbol are all accurate. Even a single incorrect digit in the Chain ID can cause communication failures and trigger the Internal JSON-RPC Error.

Confirm Sufficient Gas Token Balance

Another frequent cause is insufficient gas tokens to complete your transaction. Each blockchain network uses a different native token for gas fees—Ethereum requires ETH, BNB Chain requires BNB, and so on.

Verify you have enough tokens in your wallet to cover not just the transaction cost but also unexpected gas price spikes. If your balance is borderline, top up your account before retrying.

Update to the Latest MetaMask Version

An outdated wallet can introduce compatibility issues with certain networks. Check your MetaMask version by opening the extension and looking at the about section.

If you’re running an older version, update immediately through the Chrome Web Store if you’re on desktop, or through the App Store/Play Store on mobile. Newer versions often include bug fixes and improved RPC handling that can eliminate the Internal JSON-RPC Error.

Test Your Setup

Once you’ve made adjustments, test the connection by attempting a simple transaction or even just refreshing the network connection. If the error persists across multiple attempts, you may need to cycle through additional RPC endpoints or consider whether the network itself is experiencing broader issues.

Have you encountered the Internal JSON-RPC Error before? What solution worked for you? Drop your troubleshooting tips in the comments.