DKIM (DomainKeys Identified Mail) is an email authentication method that prevents tampering during transit. By adding a digital signature to outgoing emails, DKIM lets recipients verify the sender’s authenticity and ensures the message hasn’t been altered.
When the receiving server sees that the email is signed with an authorized DKIM signature, it understands that the email is safe to open and that it has not been modified in the transit process.
End-users typically don’t see DKIM signatures directly; validation occurs at the server level. The DKIM record, on the other hand, refers to the specially formatted text record in your DNS that has the public key. The recipients’ mail servers use this key to check and authenticate the DKIM signature.
To ensure your DKIM setup works correctly, you’ll need a reliable DKIM checker. Here are the top free tools available in 2025:
Key Takeaways
- DKIM checkers can help you ensure email integrity by validating DKIM signatures.
- While choosing the right tool may be challenging, it will help you improve email security and deliverability to a significant extent.
- Some other reliable DKIM checkers include PowerDMARC DKIM Checker, MXToolbox DKIM Lookup, DKIM Validator by Mimecast, Mail Tester DKIM Checker, and dmarcian DKIM Inspector.
Top 5 DKIM Checkers
PowerDMARC DKIM Checker
PowerDMARC DKIM Checker provides advanced DKIM record validation with detailed error reporting. PowerDMARC also provides real-time DKIM management and monitoring services. To start, you need to enter your domain name without https:// or www. Then, you can enter your selector manually or leave it blank to let the PowerDMARC system detect it automatically. The process is as simple as that, providing instantaneous results.
Benefits
- The system provides detailed results such as a valid DKIM record, public key, key algorithm, and error details.
- There is an option for automatic selection detection.
- The information is divided into individual sections based on the selector, which makes the page very easy and intuitive to navigate.
- The results are instantly accessible, and it’s very easy to start the process without technical know-how.
Drawbacks
- No option to send the results to a dedicated email address
MXToolbox DKIM Lookup
The DKIM Check allows users to conduct a DKIM record test against a domain name and selector free of charge. This tool helps check the ability to retrieve the DKIM public key using a domain and a selector. On the same page, it provides a list of commands along with explanations to make it easy for non-technical users to understand the results.
Benefits
- The platform provides quick checks for DNS configuration issues.
- It is best for quick validation of DKIM records.
- It includes links to more information next to the results.
- Includes details on how to use the tool to aid complete beginners.
Drawbacks
- No option to auto-detect selectors.
- No option to send results to your email address.
DKIM Validator by Mimecast
DKIM Validator by Mimecast helps validate DKIM records in your DNS. It provides comprehensive insights into your DKIM record setup, including information on your DKIM record validity and key tags. The information on the tags is divided into two categories: defaulted tags and declared tags, which makes the information well-structured and easy to navigate.
Benefits
- The tool has a dedicated section explaining what DKIM is at the top of the page, which is great for beginners and non-technical users.
- Next to the tag and value information, there are also descriptions for each, which makes it easier to understand the results.
- Information is well-structured and organized.
- You can get the results directly sent to your work email address.
Drawbacks
- No option to auto-detect selectors.
- To receive results by email, additional personal information such as work email, phone number, country, etc., is also needed.
Mail Tester DKIM Checker
The Mail Tester DKIM Checker works in conjunction with the SPF checker to provide results for both protocol setups. It is direct and straightforward and provides results instantly. Best suited for domain owners who wish to check both SPF and DKIM validity at the same time.
Benefits
- SPF results are available on the same page, so it’s great if you are looking for a 2-in-1 tool for quick information.
- The platform helps you identify possible security gaps in your DKIM record for better protection.
- The results can be accessed immediately, with no annoying pop-ups or advertisements disturbing the process.
Drawbacks
- No option to auto-detect selectors.
- No option to send results directly to your email for future reference.
- Doesn’t have a separate dedicated tool for DKIM record validation.
dmarcian DKIM Inspector
The dmarcian DKIM Inspector helps verify whether or not the public key portion of the DKIM signature has been published correctly. The DKIM selector value provides comprehensive information on DKIM record breakdown, including details on where the public key is located in the DNS record. The tool helps diagnose DKIM configuration issues and prevents errors and misconfigurations.
Benefits
- The platform has a visually appealing interface with clearly organized sections.
- It provides detailed information on your DKIM record and public key length.
- Comprehensive explanations help you better understand the functionality of each tag.
- A section on related blog posts on the topic to equip you with fundamental knowledge on the subject.
Drawbacks
- There is no option of getting the results emailed to you for later use.
- There is no auto-detection feature for your selector.
How to Choose the Right DKIM Checker
Some of the most important factors to consider when choosing a DKIM checker include:
Accuracy in DKIM validation
Some tools focus on the speed of results while compromising on the accuracy or depth in DKIM validation. Try to find a tool that is not only fast but also accurate, since wrong results or bugs can provide false positives during lookups. Reliable DKIM checker tools like the ones mentioned in our Top 5 list help you get error-free results every time!
Automatic DKIM Selector Detection
While most DKIM checker tools do not provide this feature, it’s always good to have! DKIM selector detection can be a hassle, especially if you don’t know how to do it or aren’t aware of it already. Using a DKIM lookup that can auto-detect your selector without manually entering it is a blessing in disguise! It saves both time and effort.
For manual inputs, read our blog on how to find your DKIM selector.
Ease of Use and Error Details
It is best when the tool combines ease of use with an intuitive interface and learning resources to make the results accessible for beginners and professionals alike.
Affordability
There are several DKIM checkers available in the market that are completely free of charge, like the examples shared above. These free tools provide detailed error highlights, accurate results, and are instant and easy to use. The best part? They don’t cost a dime, require signing up, or any credit/debit card details!
Final Words
It is important to verify your DKIM records regularly to maintain email security and integrity. Thankfully, there are numerous free tools available online that you can use to check your DKIM record and take corresponding action. After presenting some of the best DKIM checkers and detailing the factors that you need to take into consideration, it is time for you to choose what best suits your needs!
Ready to test your DKIM setup? Try PowerDMARC’s checker for instant validation.
- How to Check Email Deliverability? - April 2, 2025
- Best DKIM Checkers in 2025 - March 31, 2025
- Famous Data Breaches & Phishing Attacks: What We Can Learn - March 27, 2025