[ Free tool · Check ]
DKIM Lookup
Verify a DKIM selector is published and the key is valid.
Leave the selector blank to try 20 common ones (google, selector1, k1, s1…).
[ About this tool ]
This DKIM lookup fetches the public key at <selector>._domainkey.<domain>, decodes it and reports the key type and length.
How to read the results
- ›2048-bit RSA or Ed25519 keys are recommended.
- ›1024-bit keys still work but are weak.
- ›An empty p= value means the key was revoked.
- ›Find the selector in the s= tag of a message's DKIM-Signature header.
Frequently asked questions
How do I find my DKIM selector?
Open a sent message's original headers and look for s= in the DKIM-Signature line. Common selectors include google, selector1, selector2, k1 and s1.
How do I test DKIM?
Look up the selector here, then send a message to yourself and check the Authentication-Results header for dkim=pass.
Learn more in our guide: DKIM (DomainKeys Identified Mail)
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