Top Secure Cert Checker API alternatives in 2025

As we move into 2025, the demand for secure and reliable APIs for SSL certificate checking and validation continues to grow. Developers and businesses are increasingly looking for alternatives to traditional SSL Certificate Checker APIs to ensure their applications are secure and compliant. In this blog post, we will explore some of the top secure cert checker API alternatives available in 2025, detailing their features, capabilities, pricing, pros and cons, ideal use cases, and how they differ from existing APIs.

SSL Certificate Checker API

The SSL Certificate Checker API is a robust tool that allows users to verify and validate any SSL certificate present on a website. This API provides extensive information about the host, including the validity of the SSL certificate and the location of the SSL provider.

Key Features and Capabilities

One of the primary features of the SSL Certificate Checker API is its ability to check the validity of an SSL certificate. When a user passes a URL to the API, it returns detailed certificate information, including the issuer, validity dates, and more. This feature is crucial for security companies that need to ensure that websites are safe for their users.

{"subject":{"jurisdictionC":"US","jurisdictionST":"Delaware","businessCategory":"Private Organization","serialNumber":"3014267","C":"US","ST":"California","L":"San Jose","O":"PayPal, Inc.","CN":"www.paypal.com"},"issuer":{"C":"US","O":"DigiCert Inc","OU":"www.digicert.com","CN":"DigiCert SHA2 Extended Validation Server CA"},"validFrom":"2024-06-13T00:00:00.000Z","validTo":"2025-06-12T23:59:59.000Z","expiresInDays":215,"fingerprint":"B8:52:A5:56:6A:3C:F4:6B:0F:90:23:FA:3E:26:C8:8B:BA:55:D3:C9","fingerprint256":"BA:3F:8D:7F:72:A6:A3:5A:6E:BF:15:31:D0:79:1B:43:DA:2C:6D:0F:56:72:19:44:64:E9:40:62:7A:C7:8B:62","serialNumber":"0F689F7274A957992808A5B060F2E4E8","pem":"-----BEGIN CERTIFICATE-----\nMIIR6DCCENCgAwIBAgIQD2ifcnSpV5koCKWwYPLk6DANBgkqhkiG9w0BAQsFADB1\nMQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\nd3cuZGlnaWNlcnQuY29tMTQwMgYDVQQDEytEaWdpQ2VydCBTSEEyIEV4dGVuZGVk\nIFZhbGlkYXRpb24gU2VydmVyIENBMB4XDTI0MDYxMzAwMDAwMFoXDTI1MDYxMjIz\nNTk1OVowgcYxEzARBgsrBgEEAYI3PAIBAxMCV...

Pros and Cons

While the SSL Certificate Checker API offers extensive features, it does have some limitations. The API allows for a maximum of 5 requests per second, which may not be sufficient for high-traffic applications. However, its detailed responses and accuracy make it a strong choice for security audits and compliance checks.

Ideal Use Cases

This API is ideal for security companies, web developers, and businesses that need to monitor SSL certificate validity for multiple websites. It can be integrated into security auditing tools and compliance monitoring systems.

How It Differs from Other APIs

Compared to other SSL validation APIs, the SSL Certificate Checker API provides more detailed information about the certificate issuer and validity dates, making it a preferred choice for those needing comprehensive SSL data.

Looking to optimize your SSL Certificate Checker API integration? Read our technical guides for implementation tips.

SSL Certificate Validation API

The SSL Certificate Validation API is another powerful tool that provides comprehensive information on the SSL certificate used by a host. This API allows users to quickly obtain detailed information about the SSL certificate, including its expiration date and issuer.

Key Features and Capabilities

One of the standout features of the SSL Certificate Validation API is the ability to get detailed information about an SSL certificate. By querying the API with a hostname or IP address, users can retrieve essential data such as the expiration date, issuer details, and public key algorithm.

{"subject":{"C":"US","ST":"California","L":"Burbank","O":"The Walt Disney Company","CN":"disney.com"},"issuer":{"C":"US","O":"Entrust, Inc.","OU":["See www.entrust.net/legal-terms","(c) 2012 Entrust, Inc. - for authorized use only"],"CN":"Entrust Certification Authority - L1K"},"validFrom":"2023-05-12T21:27:49.000Z","validTo":"2024-05-19T21:27:49.000Z","expiresInDays":96,"fingerprint":"F9:7B:0C:CD:6E:54:30:58:41:38:4E:9F:CA:2D:6D:65:C4:8C:CD:1A","fingerprint256":"64:82:62:42:A3:EE:D8:73:53:7A:68:25:F2:9A:B5:0F:94:AF:27:83:AA:A1:AD:75:36:AB:A9:C2:29:19:23:B2","serialNumber":"1F06B67F40234460BDED088591DF80DF","pem":"-----BEGIN CERTIFICATE-----\nMIIGyTCCBbGgAwIBAgIQHwa2f0AjRGC97QiFkd+A3zANBgkqhkiG9w0BAQsFADCB\nujELMAkGA1UEBhMCVVMxFjAUBgNVBAoTDUVudHJ1c3QsIEluYy4xKDAmBgNVBAsT\nH1NlZSB3d3cuZW50cnVzdC5uZXQvbGVnYWwtdGVybXMxOTA3BgNVBAsTMChjKSAy\nMDEyIEVudHJ1c3QsIEluYy4gLSBmb3IgYXV0aG9yaXplZCB1c2Ugb25seTEuMCwG\nA1UEAxMlRW50cnVzdCBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eSAtIEwxSzAeFw0y\nMzA1MTIyMTI3NDlaFw0...

Pros and Cons

The SSL Certificate Validation API excels in providing detailed SSL certificate information, making it suitable for security audits and compliance checks. However, it may not offer as many features as some other APIs, which could limit its use in more complex scenarios.

Ideal Use Cases

This API is ideal for developers looking to integrate SSL validation into their applications, as well as for businesses conducting security audits and monitoring third-party sites for SSL compliance.

How It Differs from Other APIs

Unlike the SSL Certificate Checker API, which focuses on checking the validity of certificates, the SSL Certificate Validation API provides a broader range of information about the certificate itself, including its public key algorithm and signature algorithm.

Need help implementing SSL Certificate Validation API? View the integration guide for step-by-step instructions.

Secure Mail Check API

The Secure Mail Check API is designed to improve communication accuracy by providing real-time validation of email addresses. This API is crucial for businesses that rely on email communication and need to ensure the legitimacy of the email addresses they interact with.

Key Features and Capabilities

One of the primary features of the Secure Mail Check API is the Email Validate function. This feature allows users to enter an email address and receive validation results, including the status of the email, user identification, and domain details.

{"email":"[email protected]","status":"VALID","user":"johnmccart","domain":"gmail.com","stringStatus":"VALID","dnsStatus":"CONFIRMED","mailServerStatus":"CONFIRMED","smtpStatus":"CONFIRMED","message":"Valid email"}

Pros and Cons

The Secure Mail Check API is highly effective for ensuring accurate email communication, but it may not provide as much detail as some other APIs regarding the underlying infrastructure of the email servers.

Ideal Use Cases

This API is ideal for businesses during onboarding and user registration processes, where validating email addresses in real-time can significantly reduce communication errors and improve data accuracy.

How It Differs from Other APIs

While other APIs focus on SSL certificate validation, the Secure Mail Check API specifically targets email validation, making it a unique tool for businesses that prioritize email communication.

Looking to optimize your Secure Mail Check API integration? Read our technical guides for implementation tips.

Domain Checker API

The Domain Checker API is a powerful tool that reveals crucial domain details, from ownership to registration dates. This API is essential for users looking to streamline domain management and enhance security.

Key Features and Capabilities

One of the standout features of the Domain Checker API is the Domain Data function. This feature allows users to check the availability of a domain by entering the desired URL, providing information on registration status, expiration dates, and DNS settings.

{"server":"gamma","name":"yahoo.com","idnName":"yahoo.com","status":["clientUpdateProhibited (https://www.icann.org/epp#clientUpdateProhibited)","clientTransferProhibited (https://www.icann.org/epp#clientTransferProhibited)","clientDeleteProhibited (https://www.icann.org/epp#clientDeleteProhibited)","serverUpdateProhibited (https://www.icann.org/epp#serverUpdateProhibited)","serverTransferProhibited (https://www.icann.org/epp#serverTransferProhibited)","serverDeleteProhibited (https://www.icann.org/epp#serverDeleteProhibited)"],"nameserver":["ns5.yahoo.com","ns3.yahoo.com","ns1.yahoo.com","ns4.yahoo.com","ns2.yahoo.com"],"ips":"lucky7meboo.yahoo.com","created":"1995-01-18 09:00:00","changed":"2023-12-18 10:09:50","expires":"2025-01-19 06:00:00","registered":true,"dnssec":"unsigned","whoisserver":"whois.markmonitor.com","contacts":{"owner":[{"handle":null,"type":null,"name":null,"organization":"Yahoo Assets LLC","email":"Select Request Email Form at https://domains.markmonitor.com/whois...

Pros and Cons

The Domain Checker API is excellent for quickly determining domain availability and managing registrations. However, it may not provide as much detail on SSL certificates as other APIs, which could limit its use in security-focused applications.

Ideal Use Cases

This API is ideal for businesses and developers looking to register new domains or manage existing ones efficiently. It can also be integrated into domain registration platforms to streamline the user experience.

How It Differs from Other APIs

Unlike the SSL certificate APIs, which focus on SSL validation, the Domain Checker API is specifically designed for domain management, making it a valuable tool for those in the domain registration industry.

Need help implementing Domain Checker API? View the integration guide for step-by-step instructions.

Conclusion

In conclusion, as we look towards 2025, the landscape of secure cert checker APIs is evolving. Each of the APIs discussed—SSL Certificate Checker API, SSL Certificate Validation API, Secure Mail Check API, and Domain Checker API—offers unique features and capabilities that cater to different needs. Depending on your specific requirements, whether it's SSL validation, email verification, or domain management, there is an API that can meet your needs effectively. For comprehensive SSL certificate management, the SSL Certificate Checker API stands out, while the Secure Mail Check API is ideal for businesses focused on email communication. Ultimately, the best choice will depend on your specific use case and integration requirements.