Text Tools
Email Validator
Check whether an email address is correctly formatted.
Runs in your browser Your input never leaves your device.
0 characters | 0 words
—
About this tool
Paste one email address per line and the tool marks each as valid or invalid format as you type. It checks the structure only: allowed characters before the @, a domain made of labels separated by dots, and label length limits. It does not look up DNS records, contact a mail server or confirm that the mailbox exists, so a well-formed address can still bounce. Everything runs in your browser and nothing you paste is sent to our servers. Use it to clean up a list before an import or to spot typos such as a missing dot or a double @.
How to use it
- Paste or type your addresses, one per line.
- Read the result for each line: a check mark means valid format, a cross means invalid.
- Fix the flagged lines and check again.
- Copy the result if you need it elsewhere.
Example
The domain needs at least one dot, so single-label hosts like localhost fail.
Input
ada@example.com ada@@example.com ada@localhost
Result
✓ ada@example.com — valid ✗ ada@@example.com — invalid format ✗ ada@localhost — invalid format
Common problems
- A valid-looking address still bounces
- Format checks cannot tell whether the mailbox exists. Send a confirmation email to verify it.
- An address with non-English letters is marked invalid
- Only ASCII letters, digits and the usual symbols are accepted, so internationalized addresses are reported as invalid format.
- Spaces or commas break a line
- Put exactly one address on each line. Surrounding spaces are trimmed, but spaces inside an address make it invalid.