How to use the ZeroBounce API


  1. Register your new account with ZeroBounce.
  2. Verify your email by clicking the link in the email we send you.
  3. Log in to your ZeroBounce account.
  4. Access our Bulk Email Upload page.
  5. Try out our service for free by uploading a .CSV, .XLS, XLSX or .TXT file with up to 100 contacts.
  6. Review your results and decide how many emails you need to validate.
  7. Buy more credits find more details about buy credits
  8. Upload your .CSV, .XLS, .XLSX or .TXT with the emails you would like to verify.
    NOTE: Give the system approximately 45-60 minutes per 100,000 contacts.
  9. Download your new clean list by clicking on the file name underlined in green below.AResults download page

    AResults download page

  10. Select the columns you want appended on the download and then click "Download File".Select the data you need to download

    Select the data you need to download

  11. Once you download your file, you will receive an email with the unique key to unlock the encrypted .ZIP file.Your downloaded file will be encrypted

    Your downloaded file will be encrypted. After your download completes you will receive an email with the encryption key

  12. When you open the .zip file below, you will be prompted to enter the unique key above.Find your downloaded file and open it

    Find your downloaded file and open it. You will be prompted to enter the key provided to you by email

  13. Once you enter the key, you will have access to the files with your validated email results.The files will be accessible once you enter the key

    The files will be accessible once you enter the key

Validation Process FAQs

  • Do I have to register on the website to use the service?

  • No! Luckily, we have a single email verifier on the front page of our website. Check it out!

  • What is the minimum amount of records that I can validate?

  • Well, more is better than less, but the minimum purchase that we allow is 2,000 emails.

  • For how long can I use the credits I purchase?

  • Forever! ZeroBounce credits never expire. You can use them when and however you like.

  • If I didn't get my registration email, what should I do?

  • We know this can be a bother, but being patient and checking the junk folder are our best practices!

  • Can I use my credits in order to verify in real-time with your API?

  • This may seem like a leading question, but YES! You can absolutely use our API for your website forms or other creative ways to filter your email lists from the source. You can find instructions on how to do this hereto find more details about buy credits.

For more information on how to improve your email campaigns, check out our Complete Guide to Improve Inbox and Deliverability


If you need real time validations -- for example, if you want to verify your users' email addresses during the sign up process and reject them if they are invalid -- the API is going to be the faster and easier choice. If you need to validate lists, either as a one off or once every few days/weeks, then it's easier to use the browser and upload all your emails at once.