How To Fix “Internal JSON-RPC Error” On MetaMask?

How To Fix “Internal JSON-RPC Error” On MetaMask

Metamask has made its name as one of the most reliable and seamless non-custodial wallets for many crypto enthusiasts, investors, and traders. Today, Metamask boasts over 30 million active users monthly – more than any other crypto wallet.

Despite its worldwide usage, users frequently encounter a few errors and bugs while using the Metamask. Although Metamask has always been up and doing by improving user experience, most of these bugs can be nerve-wracking and frustrating.

One of the most frequently encountered errors while using Metamask is the Internal JSON-RPC Error. Most times, the error can be quite frustrating, halting Metamask users from interacting with the network, especially while exploring side chains and custom blockchain networks.

Fortunately, this article will take you through what a JSON-RPC is, methods, and the best practices to resolve the Internal JSON-RPC error.

Let’s get to it!

What is an Internal JSON-RPC Error?

JSON simply means JavaScript Object Notation. It is a lightweight data-interchange format for computers to transmit and share data between a server and a web or mobile app. It is also used to store configuration information and data.

On the other hand, the RPC (Remote Procedure Call) is a protocol that allows a computer or a program to request a callback function from a server or program.

The combination of JSON-RPC is a common implementation of RPC. JSON-RPC is a Remote Procedure Call (RPC) that is encoded in a JSON, which allows computers and programs to send commands and receive desired outcomes in a simple JSON data format.

The protocol defines a simple way to structure and encode requests and responses, making it popular for various web services and APIs. It is used in remote procedures for distributed systems to work together and communicate.

Therefore, when two computers or programs with a JSON-RPC protocol fail to communicate and work together properly, an Internal JSON-RPC error occurs.

Why Does Internal JSON-RPC Error Occur?

Internal JSON-RPC errors in Metamask usually occur due to inaccuracies in RPC settings or when one or more settings are inappropriately set up. This hinders effective communication, preventing programs from sending preferred results after initiating commands.

Therefore, before adding a network, copy RPC details from the network’s official technical documentation. Also, you critically double-check the details.

Another plausible reason for encountering an internal JSON-RPC error is using an outdated wallet or extension. The dangers of using an outdated wallet cannot be overemphasized, especially when keeping crypto assets.

Fortunately, Metamask developers are constantly working to improve usability, include newer network RPCs, and fix bugs and any vulnerabilities within an app. Therefore, it is important to check for wallet updates periodically.

Lastly, a JSON-RPC error can occur after wrongly connecting a hardware wallet with Metamask. Since both programs communicate with a JSON-RPC protocol, incorrect hardware connection hinders effective communication.

Steps to Fix Internal JSON-RPC Error

Usually, fixing a JSON-RPC error depends on the cause. Therefore, it is important to figure out the underlying cause to effectively clear up any JSON-RPC error on Metamask. Nevertheless, here are some recommended fixes for internal JSON-RPC errors:

1. Ensure the Network’s RPC Details Was Added Correctly

As mentioned earlier, an improper RPC setting can frequently result in an internal JSON-RPC error. Therefore, if you add the wrong network detail, you’ll most likely encounter this error.

To avoid this, it is important to double-check the RPC details of a blockchain network or simply automatically add a network via Chainlist. To do this:

Connect Wallet on Chainlist

Navigate to on your web browser. On the homepage, click CONNECT WALLET and select Metamask from the available options. Then, approve the connection in the prompt that pops up in your wallet.

Add Network To Metamask on Chainlist

After connecting your Metamask wallet to Chainlist, look for the specific network you’d like to connect to using the search bar at the top navigation bar.

From the search result, click on ADD TO METAMASK. Confirm the action by tapping APPROVE from the wallet prompt that pops up.

Finally, switch to the newly added network automatically by clicking on SWITCH NETWORK from the wallet prompt or manually switch to the new network from Metamask’s network dropdown.

Alternatively, you can manually add a network within Metamask with its RPC details. To do this:

Log into MetaMask extension

Log in to your Metamask with your wallet password. From the top right corner of your dashboard, click on the three dots to open your side menu.

Metamask Networks

In the Metamask menu, go to SETTINGS > NETWORKS. You can also open the network dropdown from the top left corner of the dashboard and click ADD NETWORK from there.

Add a Network on Metamask

To add a new network with its RPC details, tap ADD A NETWORK MANUALLY and complete the provided fields with the network’s correct RPC details, including:

  • Network Name
  • New RPC URL
  • Chain ID
  • Currency Symbol
  • Block Explorer URL

Ensure you double-check the RPC details and cross-check them with the provided RPC details in the network’s technical documentation. Finally, click SAVE to add the specific network to your Metamask network list.

If you face any error while adding a network with its correct RPC, you can resolve it by first removing the previously added details and then re-adding the correct one.

However, to save you from the stress, you can use Chainlist to automatically add the network.

2. Update Your Wallet/Extension

Another way to resolve internal JSON-RPC errors is by updating your Metamask wallet or extension. Updating your Metamask gives you access to updated services and network details, fixed bugs, and improved experience.

To update your Metamask app on mobile devices:

Update Metamask App

  • Navigate to the App Store for iOS devices and Google Play Store for Android devices.
  • Look for Metamask using the search filter. From the search result, click on the UPDATE button.
  • Wait for the update and download to complete, and you can enjoy the latest version afterward.

For Chrome Extension and other Chromium-based PC browsers:

  • Go to the Google Chrome Extension Store at Look for Metamask from the search field in the top navigation bar.

Remove Metamask from Chrome

  • From the results, if you see REMOVE FROM CHROME in front of the Metamask extension, then you’re using the updated version.
  • Otherwise, you can manually update your extension by clicking on the three dots in the top right corner of your Google Chrome navigation bar.

Manage Extensions in Chrome

  • This should open your browser menu. From the menu, go to EXTENSIONS > MANAGE EXTENSIONS.

Metamask Extension Detail

  • From the installed extensions, select Metamask wallet and toggle the button for DEVELOPER MODE.

Metamask Extension Developer Mode

  • The developer mode allows you to manually update, back extensions or load unpacked extensions within the Google Chrome browser.

Metamask Extension Update

  • Click on the UPDATE button and select Metamask. Once the update is complete, deactivate the DEVELOPER MODE from the Extension Menu.

3. Ensure You Connect Hardware Wallet Correctly

As mentioned earlier, Metamask wallet and hardware wallets like Ledger Nano communicate via the JSON-RPC protocol. Therefore, if after connecting your hardware wallet, you encounter an internal JSON-RPC error, you can reconnect or reactivate the hardware wallet’s bridge.

To clear internal JSON-RPC error due to incorrectly connected hardware wallet:

  • Enable Ledger Live
  • Connect the Hardware Wallet Again

Enable Ledger Live

Log into MetaMask extension

Open your Metamask wallet from the extension list and log in with your wallet password.

Metamask Wallet Settings

From the dashboard, open the wallet menu by clicking the three dots in the top right corner. In the menu, go to SETTINGS > ADVANCED.

Metamask Ledger Live Connection

From the advanced settings, look for the Ledger wallet connection setting. In the settings labeled PREFERRED LEDGER CONNECTION TYPE, select LEDGER LIVE from the dropdown options.

This option activates the Ledger Live bridge so that you can reconnect your device.

Connect the Hardware Wallet Again

After enabling the Ledger Live bridge, return to your Metamask dashboard and click on your wallet accounts in the top navigation bar.

Metamask Hardware Wallet Connection

Select the HARDWARE WALLET option to start connecting your wallet again. From the available options, select Ledger > CONTINUE.

Connecting Ledger with Metamask

A new window notifying you to open the device bridge will pop up.

Bridge between Metamask and Ledger

Click OPEN, and once the process is completed, the bridge between your Metamask and Ledger Live will be activated, and you can now seamlessly use your hardware wallet from Metamask.

4. Ensure You Have Sufficient Gas Fees

Internal JSON-RPC errors can also occur when repeatedly trying to carry out on-chain transactions with insufficient native tokens to cover gas fees.

Anytime you’re trying to process an on-chain transaction using Metamask, you must ensure you possess an ample supply of native tokens specific to the network in question, enabling you to cover the associated gas fees. Otherwise, an internal JSON-RPC error may occur.

To resolve an error caused by insufficient native tokens for gas fees, transfer additional native tokens for the network you’re engaged with to your MetaMask wallet, then process the transaction again.

Preventing Internal JSON-RPC Errors with Custom Networks and Sidechains

As blockchain technology evolves, the Ethereum network continues to grow with newer solutions. As widely known, one of the most concerning limitations of Ethereum is its scalability.

However, the emergence of ingenious and innovative scaling technologies with layer twos, sidechains, and custom networks has given a new dawn to smart contract deployment and dApp development.

With these new technologies, developers can enjoy low-cost, efficient, and cost-effective platforms for building and transferring value between chains.

Meanwhile, as these custom networks gain popularity, Metamask is committed to providing undaunting support to users moving their value and assets between the networks.

Despite these, many Metamask still encounter pitfalls like internal JSON-RPC errors while using or dealing with sidechains.

Therefore, it is important to take note of common issues like internal JSON-RPC error that occurs when using sidechains, custom networks, and other EVM-compatible chains on Metamask.

Use Trusted Custom Networks Only

While many sidechains and custom networks promise faster and cheaper asset transfer, not all are safe.

For instance, an unsafe network can threaten your personal and asset security by maliciously tracking your activities and IP address, withholding transactions, or even causing irrecoverable asset loss.

Therefore, it is important to carefully assess a new network, do your research, and ensure it is safe before adding it to your Metamask.

Add Custom Networks with their Correct RPC Details

Another way to avoid pitfalls while using custom networks and sidechains is by correctly adding RPC details. As illustrated above, you can automatically add a network using ChainList or manually add a verified network detail.

Always Fund Your Wallet with the Network’s Native Token for Gas Fees

Like layer one networks, processing transactions on sidechains and custom networks requires paying gas fees in their native tokens. However, this gets tricky with newer custom networks using ETH as their gas token.

For instance, Polygon’s gas fee is paid in MATIC, while Arbitrum’s gas token is in ETH. Therefore, It is important to familiarize yourself with a custom network, its native token, and its gas token.


In conclusion, JSON-RPC protocol is an important component of inter-computer communication. Hence, encountering an internal JSON-RPC error while using Metamask can be daunting.

However, we’ve gone over the major causes and effective steps to resolve an internal JSON-RPC error in Metamask, emphasizing the importance of ensuring correct RPC details, updating your wallet or extension, and connecting hardware wallets accurately.

Additionally, maintaining an adequate supply of native tokens for gas fees is crucial to prevent this error during on-chain transactions.

As the crypto landscape evolves with new scaling technologies, it’s essential to be cautious when dealing with sidechains and custom networks on MetaMask.

Using trusted custom networks, adding them with correct RPC details, and funding your wallet with the network’s native tokens for gas fees are vital practices to ensure a seamless experience.

By following these guidelines, users can navigate the intricacies of the “Internal JSON-RPC Error” and enjoy a smoother experience while interacting with the ever-expanding world of blockchain and cryptocurrency.

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