How to use JS Email Validator
- Start by entering an email address or domain in JS Email Validator.
- Trigger JS Email Validator and it sends the DNS lookups from your browser, not from this site.
- Review the result, which JS Email Validator fetches live from a public DNS resolver.
About this tool
There is no server of ours behind JS Email Validator. JS Email Validator validates an address syntax locally, then checks the domain MX, SPF and DMARC records over DNS-over-HTTPS.
Proving a specific mailbox exists requires sending mail, which a browser cannot do, so JS Email Validator focuses on the DNS signals that genuinely can be checked. The MX, SPF and DMARC checks are DNS queries sent from your browser to a public resolver; this site has no backend and never sees them, and a connection is required.
Frequently asked questions
What does JS Email Validator do?
JS Email Validator validates the address format and checks the domain's MX, SPF and DMARC records via DNS from your browser.
Do I need an account for JS Email Validator?
No — JS Email Validator needs no account, sign-up or installation.
Where does JS Email Validator run its checks?
JS Email Validator runs DNS lookups (MX, SPF, DMARC) from your browser against a public DNS-over-HTTPS resolver. This site has no backend and never sees them; the public resolver does.
Can JS Email Validator confirm a mailbox really exists?
JS Email Validator checks address syntax and the domain's MX, SPF and DMARC via DNS-over-HTTPS; proving a live mailbox needs to send mail, which a browser cannot do.