Quick deliverability check
Is your DKIM key lock-tight — or one rotation away from a failed signature?
Pick a selector from the curated list (defaults to google), paste any sending domain, and we'll resolve the DKIM TXT record at <selector>._domainkey.<domain>, parse the RFC 6376 tags (v=, k=, h=, t=, c=, p=), and ask the analyst for a 0-100 score plus 3-5 plain-English findings. The summary anchors on four concrete axes — key length (RSA bits / Ed25519), hash choice (sha256 vs sha1), missing canonicalization tag, and replay-scope (t= flag).
<selector>._domainkey.<domain> over DNS, parse the RFC 6376 tags (v=, k=, h=, t=, c=, p=), flag the key length and hash-algorithm safety, and ask the analyst for a 0-100 score plus 3-5 plain-English findings.Drop your email above — we'll only ping you about the monitor. No newsletters, no upsells.
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DKIM validator — frequently asked questions
Related sender-reputation check
Check blocklist status too
SPF, DKIM, and DMARC cover authentication; blocklist status is another part of sender reputation. Check your sending domain or IP against DNS blocklists.
Run the blacklist lookup checker →Pair this checker with the guide
Want the step-by-step walkthrough?
The DKIM setup pillar guide explains how DKIM signatures are generated and verified, how to publish the public key as a TXT record at <selector>._domainkey.<domain>, what a 2048-bit key vs an Ed25519 key requires, how multiple selectors compose per ESP, and how the canonicalization tag (c=) ties back to your mail server's body normalisation. Read it when you are setting up a new selector, rotating a compromised key, or onboarding a new ESP.
Pair this checker with the guide
Looking for the bigger deliverability picture?
DKIM is one of four DNS records that govern deliverability. The email authentication pillar walkthrough explains how DKIM composes with SPF, DMARC, and BIMI as one stack — what each protocol does in the receiver, the order to publish each record so the next layer does not break the previous one, and why Google and Yahoo made all four mandatory in 2024. Read the pillar before publishing DKIM for the first time.
Read the email authentication guide →