DKIM record checker
Enter your domain and DKIM selector to see the public key your email provider published. You get a pass, warning or fail result in plain English, a note if the key is revoked or only 1024-bit, and the raw record to copy.
Amazon SES uses Easy DKIM: three CNAME records named with random tokens (token._domainkey.yourdomain.com), so there is no fixed selector. Copy a token from the SES console, or read the s= tag from an email you sent through SES.
What is DKIM?
DKIM (DomainKeys Identified Mail) lets your email provider sign every message it sends for your domain with a private key. The matching public key is published in DNS as a TXT record at <selector>._domainkey.yourdomain.com. Receiving servers use it to check that the message really came from your domain and wasn't changed on the way. Together with SPF and a DMARC record, it helps keep your form emails out of spam.
How to find your DKIM selector
- Open an email you received from your domain (send yourself one if needed).
- Show the original message or full headers (in Gmail: the three-dot menu, then "Show original").
- Find the
DKIM-Signatureheader. Thes=tag is the selector and thed=tag is the domain. - Enter both above and press Check DKIM.
FAQ
What does this DKIM checker look up?
One public DNS TXT record: <selector>._domainkey.yourdomain.com. It shows whether a key is published, the key type, an approximate RSA key size, whether the key is revoked (empty p=) and whether testing mode (t=y) is on. Nothing else is queried.
Why does it say no DKIM record found?
Most often the selector is wrong. Each email provider picks its own selector, and one domain can have several. Open an email you sent, find the DKIM-Signature header and use its s= value. If that still finds nothing, DKIM isn't turned on in your provider yet.
Is a 1024-bit DKIM key still OK?
It still works, but 2048-bit RSA keys are the current recommendation. Most providers let you create a 2048-bit key under a new selector; publish it, switch signing to it, then remove the old record.
How does Amazon SES DKIM work?
SES Easy DKIM adds three CNAME records named with random tokens (token._domainkey.yourdomain.com) that point to keys Amazon hosts. There is no fixed selector, so copy a token from the SES console or read the s= tag from an email sent through SES.
Do I need DKIM if I already have SPF and DMARC?
Yes. DMARC passes when SPF or DKIM passes and lines up with your From domain. DKIM survives forwarding, where SPF often breaks, so having both makes your form emails far more likely to reach the inbox.
Email deliverability checker · DMARC record generator · What DKIM means · Why form emails go to spam
More free form tools
Form backend cost calculator
Enter monthly submissions and compare the cheapest listed plan across eight form backends.
Email deliverability checker
Enter a domain to check its SPF, DMARC and MX records and get a plain-English fix for each.
SPF record checker
Look up a domain's SPF record, see each mechanism explained and count DNS lookups against the 10-lookup limit.
DMARC record generator
Pick a policy and report address and copy a ready _dmarc TXT record.
DMARC checker
Look up a domain's DMARC record and see the policy and every tag explained.
SPF record generator
Tick your email providers and copy one SPF TXT record with a lookup count.
Contact form spam checker
Paste form HTML to audit its honeypot, endpoint, CAPTCHA markers and spam resistance.
Honeypot field generator
Generate a hidden anti-spam input with your chosen name and hiding technique.
Form action URL tester
Check a form action URL for reachability, CORS headers, POST acceptance and backend.
Email obfuscator
Encode your email so spam scrapers can't read it but people can still click it.
Mailto link generator
Build a mailto: URL with recipients, CC, BCC, subject and a pre-filled body.
Alphanumeric regex tester
Test letters and numbers only, spaces, handles and Unicode; copy validation patterns.
Email regex tester
Test the WHATWG email regex and two other patterns against edge cases and your own list.
Phone number regex tester
Test numbers against E.164, US/Canada and digits-only patterns and copy code snippets.
ZIP code regex tester
Test US ZIP, ZIP+4, Canadian and UK postal codes and copy the regex or HTML pattern.
Number regex tester
Test digits, decimals, money and thousands separators and copy validation patterns.
Date regex tester
Test dd/mm/yyyy, mm/dd/yyyy and ISO dates with leap-year checks and copy JS or HTML patterns.
Name regex tester
Test name patterns for O'Brien, accents and Unicode letters; copy JS or HTML pattern snippets.
Username regex tester
Test username presets for GitHub, Instagram and X; check reserved names and copy JS or HTML patterns.
IP address regex tester
Test IPv4, IPv6, CIDR and private-range patterns and copy JS or HTML pattern snippets.
URL regex tester
Test website URLs against http(s) regex patterns and new URL(), and copy JS, HTML or PHP code.
HMAC-SHA256 generator
Generate and verify webhook signatures for common providers in your browser.
URL encoder and decoder
Encode text, build an x-www-form-urlencoded body or parse a query string.
Password regex generator
Pick strength rules, test passwords live and copy the regex or HTML pattern.
UTM builder
Build campaign URLs with UTM parameters, tag a CSV in bulk and check tagged links.
HTML to JSX converter
Paste HTML and get JSX or a working React/Next.js form component.
Image to Base64 converter
Convert images to Base64 data URLs in your browser and copy HTML and CSS snippets.
Base64 to image converter
Paste a Base64 data URI to preview and download the decoded image.
Base64 decode & encode
Decode Base64 to readable UTF-8 text or encode text to Base64, locally in your browser.
URL to Base64 converter
Fetch a direct image URL in your browser and get its Base64 data URL.
HTML form generator
Build a form visually and copy HTML, React JSX or Tailwind code.
AI form generator
Describe your form in plain English and copy working HTML.
Time regex tester
Test 24-hour, AM/PM and ISO time patterns and copy JavaScript, Python or HTML snippets.
Credit card regex tester
Test Visa, Mastercard 2-series, Amex and more card patterns with brand detection and a Luhn check.
Hex color regex tester
Test #RGB, #RRGGBB and alpha hex colors plus rgb() and hsl() values with live color swatches.
UUID regex tester
Test UUID v1-v8, nil/max and GUID formats with version and variant checks; copy JS or HTML patterns.
Terms explained in the form glossary: DKIM, SPF, DMARC