Validate a list of email addresses
Paste your addresses and check every one for valid format in an instant — with the exact reason for anything invalid, plus smart suggestions for common domain typos. Runs entirely in your browser. No sign-up.
Why validate email addresses?
A single mistyped address means a bounced email, a lost lead, or a message that never arrives. Lists pulled from forms, spreadsheets and exports are full of small errors — a missing dot, a stray space, a @gmail.con where @gmail.com was meant. Checking the format before you send keeps your bounce rate down and protects your sender reputation.
What counts as a valid email address?
A valid address needs all of these:
- A name before the
@with no illegal characters or misplaced dots. - Exactly one
@symbol. - A domain with at least one dot and a valid ending, like
.comor.co.uk. - No consecutive dots, and no dots or hyphens at the edges.
- Sensible length — up to 64 characters before the @ and 254 in total.
This tool applies each of those rules and tells you exactly which one an address breaks, rather than a vague "invalid."
Format checking vs. mailbox verification
This is a format validator: it confirms an address is well-formed and flags likely typos, all privately in your browser. It does not ping the mail server to confirm a mailbox is live — that can't be done without sending your list to a third-party service. For cleaning up real lists, format validation removes the large majority of problem addresses. Need to build the list first? Use the email extractor to pull addresses out of text, then remove duplicates before validating.
Frequently asked questions
How do I validate a list of email addresses?
Paste your addresses into the box on the left — one per line, or separated by commas or semicolons. Each address is checked instantly and marked valid or invalid, with the reason shown next to anything that fails. Then copy or download the valid ones.
What does this email validator check?
It checks the syntax and structure of each address the way a mail server would: a valid name before the @, exactly one @, a proper domain with a valid ending (TLD), no illegal characters, no misplaced or doubled dots, and correct length limits. It also flags likely typos in common domains — for example gmial.com or gmail.con — and suggests the intended spelling.
Does it check whether the mailbox actually exists?
No — and that's deliberate. Confirming a mailbox exists requires contacting the mail server, which would mean sending your list to a third party. This tool validates format and structure entirely in your browser so your list stays private. It catches the large majority of bad addresses — typos, malformed entries and impossible formats — without uploading anything.
Is my email list uploaded anywhere?
No. All validation runs locally in your browser using JavaScript. Your list is never uploaded, stored, or logged — nothing leaves your device. You can even go offline and it keeps working.
Can I export only the valid addresses?
Yes. Copy just the valid addresses to your clipboard, or download them as a CSV. You can also copy the invalid ones separately so you can review or fix them.
Is there a limit on how many emails I can check?
No. There are no limits on list size or how often you use it. Because everything runs on your device, you can validate large lists as often as you like, for free.