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How to use the ZeroBounce API

Below you will find the instructions on how to use our API, it's very easy to use and requires SSL. The API requires that you have an active credit balance and will never consume a credit for any unknown result. This endpoint can be called asynchronously and is currently not rate limited.

To test out or API without using credits - Please use the emails provided in our sandbox documentation.

The response time for our API is between one second and 70 seconds. Since API's are meant to be fast by nature, we limit the amount of time we spend validating an email address. So if we encounter a slow mail server or a mail server with a greylisting algorithm you will get an unknown result. You can always re-validate those conditions, uploading a file to the bulk email validator.

On average 96-98% of all domains will return in 1 to 5 seconds, there are a handful of domains that run off Postfix/Dovecot that have a 20 second connection time for real-time validations and a very small fractional percentage of other domains that are very slow to respond to SMTP inquiries. All the major ISP will return in 1 to 3 seconds, which is usually the majority of most email distribution.



API URL (With GEO Append):

URL Parameters

  • Parameter
  • email
    The email address you want to validate
  • ipAddress
    The IP Address the email signed up from (Can be blank, but parameter required)
  • apiKey
    Your API Key, found in your account

If you want to call the API from your browser to test it, all you need to do is to replace the API KEY with your key:
or if you don't need GEO Append simply call the validate method.

The API will return these results in a JSON format using the "validate" method.

  • Properties
  • address
    The email address you are validating.
  • status
    [valid, invalid, catch-all, unknown, spamtrap, abuse, do_not_mail]
  • sub_status
    [antispam_system, greylisted, mail_server_temporary_error, forcible_disconnect, mail_server_did_not_respond, timeout_exceeded, failed_smtp_connection, mailbox_quota_exceeded, exception_occurred, possible_traps, role_based, global_suppression, mailbox_not_found, no_dns_entries, failed_syntax_check, possible_typo, unroutable_ip_address, leading_period_removed, does_not_accept_mail, alias_address]
  • account
    The portion of the email address before the "@" symbol.
  • domain
    The portion of the email address after the "@" symbol.
  • disposable
    [true, false] If the email domain is disposable, which are usually temporary email addresses.
  • toxic
    [true, false] These email addresses are known to be abuse, spam, or bot created.
  • firstname
    The first name of the owner of the email when available or [null].
  • lastname
    The last name of the owner of the email when available or [null].
  • gender
    The gender of the owner of the email when available or [null].
  • creationdate
    The creation date of the email when available or [null] [Obsolete].
  • location
    The location of the owner of the email when available or [null] [Obsolete].
  • processedat
    The UTC time the email was validated.

The API will return these additional fields using the "validatewithip" will return these additional additional fields using the validatewithip method:

  • Properties
  • city
    The city of the IP passed in.
  • region
    The region/state of the IP passed in.
  • zipcode
    The zipcode of the IP passed in.
  • country
    The country of the IP passed in.



Successful Response
Successful Response with IP
Error Response

API Validation V1 and V2 Rate Limits

We allow a maximum of 50.000 requests in 10 seconds (validations) for the and before temporarily blocking for 1 minute.

Bad API key requests to and 200 times in 1 hour will result in a temporary block for 1 hour.