Free DKIM Lookup Tool

Free DKIM Record Checker
For Any Domain

Paste in a domain and we'll scan 30+ selectors used by Google, SendGrid, Mailgun, Klaviyo, HubSpot, Mailchimp, ActiveCampaign and more to find its DKIM signing key — and show you the key type and strength.

Free, no signup required. 10 checks/hour per IP.

Common questions

What is a DKIM record?
DKIM (DomainKeys Identified Mail) is a cryptographic signature added to outgoing mail headers. Receiving servers look up the matching public key at selector._domainkey.yourdomain.com to verify the message wasn't altered in transit and really came from an authorized sender.
Why didn't this tool find my DKIM record?
DKIM keys live at a selector-specific hostname (e.g. s1._domainkey.yourdomain.com), and the selector name varies by ESP and is sometimes randomized per account. We check 30+ of the most common selectors, but a custom or rotated selector may not be on that list — check your ESP's DNS setup instructions for the exact selector name, or inspect the DKIM-Signature header (look for 's=') in a received email.
What key size should my DKIM record use?
2048-bit RSA is the current standard and what most ESPs issue by default. 1024-bit keys are considered weak and some mailbox providers are starting to disregard them; if you find a 1024-bit key, ask your ESP about rotating to 2048-bit.
Can I have multiple DKIM selectors?
Yes — and it's common. Many domains run DKIM for several ESPs at once (e.g. Google Workspace for regular mail plus Klaviyo for marketing campaigns), each with its own selector. All of them should pass verification independently.