DKIM Checker
Query {selector}._domainkey.{domain} for the DKIM TXT public key.
Ready to Analyze
Enter a target value above or click any sample preset chip to generate real-time diagnostic output.
About the DKIM Checker
The DKIM Checker queries the DKIM public key TXT record for a domain and selector, showing you the key algorithm, size, flags and full public key. DKIM (DomainKeys Identified Mail) is the cryptographic half of modern email authentication — it puts a signature on every outbound message using a private key held by your mail server, and receivers verify that signature against the public key you publish in DNS.
Because DKIM keys live at selector-specific hostnames (`selector._domainkey.yourdomain.com`), verifying setup means knowing which selectors your mail platform uses. Google Workspace uses `google` by default; Microsoft 365 uses `selector1` and `selector2`; Mailchimp uses `k1`; SendGrid uses `s1` and `s2`. This tool lets you enter any selector and confirm the key is published, well-formed and using a modern key size (2048-bit RSA is today's standard).
Use DKIM Checker whenever you set up a new sending platform, rotate keys as part of your security hygiene, or debug why a domain's DMARC is failing. A missing or malformed public key silently breaks DKIM verification, which cascades into DMARC failure and inbox-placement problems.
Enter the required value in the input field above (domain, IP, URL, or text depending on the tool).
Click the action button to run the check — results are computed instantly from our edge network.
Review the parsed output, key fields and any warnings shown in the result card.
Copy the result, share the page URL, or jump to a related tool from the sidebar to continue debugging.
- Selector-aware lookup — supports any provider
- Key size and algorithm display
- Detects revoked keys (empty p= value)
- Handles multi-string TXT records (long 2048-bit keys)