host.tools

DKIM tester

Email /api/v1/email/dkim

Look up DKIM keys for any selector. Auto-tries common selectors.

Try: host.com google.com checkhost.com hostinfo.com [email protected]
Related: MX lookup SPF tester DKIM tester DMARC tester SMTP test

3 selectors returned a key

Domain: github.com

google._domainkey length: 410 
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAj6T5sl/RwdSqGoYWaWaFbS2UAeyPrEmd0gogocmRfS441qwR8/0KB81Hw89P0l4YiFRrXYk7NVIGfyCRHAYYZUzCkGeOysI2EjgzLFhd/NEsbRzOEc/kWkK/RO6JFq/5lOn6M9AZw/ap9tds4JG9ApgNNdSpPxp9DmvpsOSgNMVflRxQFrk3kdS4RNAPKu/OPoA7dlR/A/pECryjRoYgENtDXzdnK70HgCekems6UDzxDj61cjyoKoXtEMF/QsaHEQ1Gjfv014rDJBsubk/kT5VqHkWHa/ia68Z5r228Ety/wFfQNjXTx/J7KGZ9GkZlKED659eiJcLnWcKDSiQlhwIDAQAB
selector1._domainkey length: 235 
v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCxZC/z2cK+2s1f/ktzSDSeFzkfIHrjwtGFsfKMAYvKaXjPVNzKykpbXBkX5nB7dVUTFttda7aROr2iSrIseQ27Ui+4rUZVzgFanE8RaXhYM9n5wPKNv8GtLJk7JgcsYZ7ErgID4uW2sEYyV/dnRYw6rDzOaeRKkKELTUfJI5ebLQIDAQAB;
k1._domainkey length: 226 
k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDbNrX2cY/GUKIFx2G/1I00ftdAj713WP9AQ1xir85i89sA2guU0ta4UX1Xzm06XIU6iBP41VwmPwBGRNofhBVR+e6WHUoNyIR4Bn84LVcfZE20rmDeXQblIupNWBqLXM1Q+VieI/eZu/7k9/vOkLSaQQdml4Cv8lb3PcnluMVIhQIDAQAB;
How to use DKIM tester
  1. 1
    Paste your input

    Enter the value at the top — domain, IP, URL, email, ASN, hash, whatever fits this tool. The smart input auto-detects type.

  2. 2
    Click "Inspect"

    host.tools issues real probes (DNS, HTTP, TCP, TLS, WHOIS where applicable) and renders the result in milliseconds.

  3. 3
    Open the API tab

    Every web tool has a sibling /api/v1/email/dkim JSON endpoint with the same payload. One copy-as-curl click and you're scripting it.

Why this matters

SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT — six little records decide whether your mail lands in the inbox or the spam folder. Get them right once, sleep better forever.

API equivalent
/api/v1/email/dkim?q=support%40github.com 
curl -s '/api/v1/email/dkim?q=support%40github.com'
Embed this tool
<iframe src="/email/dkim?q={INPUT}&embed=1"
  width="100%" height="600" frameborder="0"></iframe>

Drop into any HTML page. The embed=1 flag hides nav and footer.

FAQ · DKIM tester

Common questions

Is DKIM tester free?
Yes — every tool is free on the web with a 200/hour rate limit per IP. The matching API endpoint /api/v1/email/dkim is free up to 100 requests/hour, no key required.
Where does the data come from?
Real-time probes against authoritative sources (DNS root, RIRs, registries, the target server itself), plus partner data feeds from hostinfo.com (GeoIP/ASN) and hostcheck.com (reputation).
How fresh are the results?
Live by default. Cached for 5 minutes to make repeat queries instant; pass ?nocache=1 for a forced refresh.
Can I run this from the command line?
Yes — every tool ships with a copy-as-curl. There's also an official CLI: host.tools email dkim YOUR_INPUT.
Can I monitor results over time?
Pro tier lets you schedule any tool to run every 1/5/15/60 min and alert on diff. See monitors.
host.tools Pro

Run DKIM tester on a schedule. Get pinged when it changes.

Pro gets you bulk lookups, monitors, webhook alerts, history, exports and 10,000 API calls/day. $19/mo.

See pricing Tour monitors
  • ✓Schedule any tool — every 1, 5, 15, 60 min
  • ✓Diff against last run, alert on change
  • ✓Webhook + email + Slack + PagerDuty + OpsGenie
  • ✓Bulk CSV upload, 1,000 inputs per job
  • ✓Export results as CSV / NDJSON / Excel
  • ✓90-day history, comparison view