Get an API key
Sign-up isn't self-serve yet, so a person sends your key. Tell us roughly what you're checking and you'll have it without a sales call.
What happens after you ask
We read the request
A person does, not a sequence. If your volume or use case needs a different setup, that's the reply you get, rather than a generic welcome.
You get two keys
A live key, and a sandbox key that starts zb_test_ and never spends a credit. The sandbox has reserved addresses for each result, so you can build your branches before you send us a real one.
You make one POST
Send an address to /v1/verify and read result. It is one of four values: valid, invalid, catch_all or unknown. Role, disposable and free-provider come back as separate true or false flags.
You only pay for answers
The first 100 checks each month are free. After that, a credit is spent when we return valid, invalid or catch_all. An unknown costs nothing, and neither does a duplicate in the same batch.
Ask us for a key
Sign-up isn't self-serve yet. Email us your monthly volume and what you're building, and we'll send a key. The first 100 checks each month are free and need no card.
Email usWhat it costs once you're past the free checks
Credits never expire, so buy the pack that fits the list in front of you and not the one that fits a forecast.
| Credits | Price | Per address |
|---|---|---|
| 1,000 | $5 | $0.00500 |
| 10,000 | $25 | $0.00250 |
| 50,000 | $89 | $0.00178 |
| 100,000 | $139 | $0.00139 |
| 500,000 | $549 | $0.00110 |
| 1,000,000 | $949 | $0.00095 |
One credit is one answer on one distinct address. Unknown results, duplicates, our errors and every sandbox call are free.
Questions before you ask
How long until I get the key?
A person sends it, so it depends on the hour. We would rather tell you that than promise a number of minutes we haven't measured.
Do I need a card for the free checks?
No. The 100 free checks a month need no card, and they reset on the first of the month. They don't roll over.
Can I try it before I ask for a key?
Yes. The free checker on this site inspects one address in your browser without a key. It checks the shape of the address and flags role, throwaway and consumer-webmail patterns. It can't look up mail records or talk to the mail server, which is the part that needs the API.
Is there an SDK?
Not yet. The API is one JSON POST, and the library pages show it as plain HTTP in each language, which is usually less code than an SDK would add.
What do you do with the addresses I send?
We check them and hold the results until you delete the job. Retention is a setting on your account, and the privacy and data processing pages say exactly what leaves our infrastructure during a check.