The importance and techniques of providing meaningful error messages to users (Error Handling In Solidity, pt. 5)

Favour AjayeFavour Ajaye
8 min read

Error Handling In Solidity, pt. 5

Finally, we've reached the end of error handling in Solidity.

In Part 1, we talked about the importance of error handling in solidity, potential risks and vulnerabilities, and the impact of error handling on user experience and contract security.

In Part 2, we saw The different types of exceptions that can occur in Solidity contracts, like Assertion Failure, Out-of-Gas Exceptions, Invalid Operations, Revert and Require Statements, External Call Exceptions, Custom exceptions, and Low-Level exceptions, with their code examples.

In Part 3, we discussed the try-catch mechanism, how it improves error handling and How try/catch improves error handling in solidity.

In Part 4, we looked at the differences between assert and require statements in Solidity and when to use assert and require statements based on expected behavior and contract logic.

Now we will be diving into the importance of providing meaningful error messages to users, techniques for constructing informative error messages in Solidity contracts, and best practices for effective error handling in Solidity.


The importance of providing meaningful error messages to users

Providing meaningful error messages to users is of paramount importance in Solidity contracts. Here are the key reasons why meaningful error messages are crucial:

Enhanced User Experience

  • Meaningful error messages improve the user experience by providing clear and concise feedback when errors occur. Users can quickly understand what went wrong and take appropriate actions to resolve the issue. This reduces frustration, confusion, and the likelihood of repeated errors.

Error Resolution:

  • Clear error messages help users identify and troubleshoot the root cause of the error. With informative messages, users can make informed decisions on how to rectify the error, adjust their inputs, or seek assistance from support channels. This facilitates efficient error resolution and enables users to complete transactions or interactions successfully.

Transparency and Trust

  • By providing transparent error messages, you foster trust and credibility with your users. Transparent error handling demonstrates that you value their experience and are committed to open communication. It shows that you have designed your contract with their best interests in mind and are actively working to ensure their smooth interaction with the system.

Security and Fraud Prevention

  • Detailed error messages can help prevent security breaches and fraudulent activities. By providing specific error messages, you can alert users to potential risks, such as invalid inputs or unauthorized actions. This empowers users to detect and report suspicious activities, enhancing the security of the contract ecosystem.
  • In certain cases, contracts may have compliance or legal requirements. Providing meaningful error messages can assist with regulatory compliance by ensuring that users are informed about the contractual terms, obligations, or limitations. It helps meet transparency standards and reduces the risk of legal disputes or non-compliance issues.

Reputation and User Adoption

  • Contracts that consistently provide clear and helpful error messages gain a reputation for being user-friendly and reliable. Positive user experiences lead to increased adoption, usage, and user recommendations, fostering a positive reputation for the contract and promoting its growth.

Techniques for constructing informative error messages and Best practices in Solidity contracts

Constructing informative error messages in Solidity contracts is crucial for providing users with clear and actionable feedback. Here are some techniques to consider when creating informative error messages:

Be Specific and Clear:

  • Clearly state the nature of the error. Specify what went wrong and provide details about the error condition. Avoid generic or ambiguous error messages that do not convey the underlying issue.

  • Use plain language that is easy for users to understand. Avoid excessive technical jargon or complex terminology that might confuse users who may not be familiar with the intricacies of the contract.

Provide Contextual Information:

  • Include relevant context in the error message to help users understand the cause of the error. This may involve mentioning the specific function or operation that encountered the error, the inputs or parameters involved, or any relevant state or condition within the contract.

  • If applicable, provide additional information about the expected values or conditions that were not met. This helps users identify discrepancies and take appropriate corrective actions.

Offer Actionable Guidance:

  • Suggest potential solutions or actions that users can take to resolve the error. Provide clear instructions on how users can rectify the issue, adjust their inputs, or navigate to an alternative pathway.

  • Include references to relevant documentation, support channels, or resources that can assist users in troubleshooting the error. This empowers users to seek further assistance if needed.

Handle Security-Sensitive Errors Carefully:

  • When dealing with security-sensitive errors, be cautious about the level of information disclosed. Avoid exposing sensitive information or details that may be exploited by malicious actors. Provide enough information to guide users without compromising security.

  • Consider providing generic error messages for certain security-sensitive scenarios, coupled with additional guidance on how users can contact support or security teams for further assistance.

Consistency and Localization:

  • Maintain consistency in the format and tone of your error messages throughout the contract. This establishes familiarity for users and enables them to understand and interpret the messages consistently.

  • If your contract is intended for international users, consider implementing localization techniques to present error messages in the users' preferred language. This can greatly enhance user comprehension and engagement.

Test and Iterate:

  • Test your error messages thoroughly during the development and testing phases of your contract. Verify that the messages accurately convey the intended information and provide the necessary guidance.

  • Solicit feedback from users and consider their suggestions for improving the clarity and effectiveness of your error messages. Continuously iterate and refine the messages based on user input and real-world usage scenarios.


Best practices for effective error handling in Solidity

When it comes to effective error handling in Solidity, here are some key best practices to keep in mind:

Avoid Excessive Gas Consumption:

  • Be mindful of gas consumption when implementing error-handling mechanisms. Excessive gas usage can lead to higher transaction costs and potential out-of-gas errors. Optimize your code to minimize gas consumption, especially in error scenarios, to ensure cost-efficient contract execution.

  • Try using custom errors if you can. It is cost effective. Read this article on Solidity custom errors: a way to save gas

Favor Explicit Error Messages:

  • Provide explicit and meaningful error messages to users. Clear and informative messages help users understand the issue and take appropriate actions to resolve it. Avoid generic error messages that do not convey specific details or guidance.

Prioritize Security:

  • Prioritize security in error handling. Be cautious about revealing sensitive information or exposing vulnerabilities through error messages. Avoid disclosing implementation details that could be exploited by malicious actors. Strike a balance between transparency and security considerations.

Implement Granular Error Handling:

  • Use granular error handling mechanisms, such as try-catch blocks, to catch and handle specific exceptions. This allows for more targeted and controlled error management, ensuring appropriate responses based on the nature of the error.

Test and Validate Inputs:

  • Validate user inputs and external data to prevent invalid or malicious inputs from affecting contract execution. Implement input validation checks using require statements to ensure that inputs meet specified requirements before proceeding with contract operations.

Log Errors for Debugging and Monitoring:

  • Log error information using events to facilitate debugging and monitoring. Emit events with relevant error details to capture important information that can be later retrieved and analyzed. This aids in identifying patterns, diagnosing issues, and tracking contract behavior.

Maintain Consistency and Readability:

  • Maintain a consistent and readable coding style throughout your contract, including error handling code. Follow established Solidity best practices, such as adhering to proper naming conventions, using meaningful variable and function names, and organizing your code in a logical manner. This promotes code readability and maintainability.

Thorough Testing and Auditing:

  • Conduct comprehensive testing and security audits to identify and address potential error scenarios. Test your contracts under different conditions and scenarios to ensure robustness and resilience. Engage external auditors to review your contract code for security vulnerabilities and potential error handling issues.

By adhering to these best practices, you can improve the reliability, security, and user experience of your Solidity contracts. Effective error handling not only helps prevent and handle exceptional conditions but also contributes to the overall trustworthiness and success of your smart contract applications.


Error handling in Solidity is crucial for ensuring the reliability, security, and user-friendliness of smart contracts. Solidity provides various mechanisms for handling exceptions, including the use of require and assert statements to validate input and enforce contract conditions, and try-catch blocks to gracefully handle errors during external contract calls and creations. By incorporating explicit error messages and appropriate conditions, developers can prevent unexpected behavior, revert operations when exceptional conditions occur, and provide meaningful feedback to users. Prioritizing gas efficiency and security while employing best practices for error handling ensures robust and dependable smart contracts that mitigate potential risks and promote a positive user experience on the blockchain.


Finally!!! We can draw our curtains here on error handling in solidity.

Check out my other articles on Solidity Basics (Solidity Data Types and Operators)**, [solidity inheritance](favourajaye.hashnode.dev/solidity-inheritance), Solidity fallback function and function overloading, Variables and control structures in solidity, Solidity Functions, Libraries in solidity, Abstract contracts and Interfaces in solidity, [Guidelines on becoming a Blockchain Developer in 2023 (Solidity)](medium.com/coinsbench/guidelines-on-becomin..), [What is blockchain?](medium.com/web3-magazine/what-is-blockchain..), [All you need to know about web 3.0](medium.com/web3-magazine/all-you-need-to-kn..), [Solidity: Floating points and precision](medium.com/@favoriteblockchain/solidity-flo..), and others

Click here to see the Github repo for this 100 days of solidity challenge.

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Written by

Favour Ajaye
Favour Ajaye

smart contract developer