Hunter.io alternative: the emails, as one free file

The last row is Hunter's, from its data page: an index of the public web, of every country. Datacircle's free file is a U.S. snapshot, and its API answers the LinkedIn profile behind a URL, not an email.

In the web app, Bulk Domain Search finds up to 10 emails a credit at the domains you upload: at best a tenth of the prices above, from $2.45 per 1,000 on Starter monthly to $0.84 on Scale billed yearly. Hunter's API has no bulk domain search: there, each email found is a credit.

Each person has a name, a current title and a LinkedIn profile URL, and is joined to their company: its website, LinkedIn page, industry, employee range and headquarters, where the file has them. Every column, with its fill rate: the free US B2B leads dataset.

Unzip the file into us_10m/ and pip install duckdb. Each search below ran on the October 2026 file, on a laptop. Domain Search, every email at a domain:

import duckdb

duckdb.sql("create view people as select * from 'us_10m/us_smb_mid_market_persons.parquet'")

# Every email at one company's domain, with the name and title
duckdb.sql("""
  select FULL_NAME, CURRENT_JOB_TITLE, EMAIL, LINKEDIN_URL
  from people
  where split_part(EMAIL, '@', 2) = 'acme.com'
""").show()

Bulk Domain Search, for a whole list of domains, written to a CSV:

# domains.csv: your list, one domain a line under a "domain" header
duckdb.sql("""
  copy (
    select d.domain, p.FULL_NAME, p.CURRENT_JOB_TITLE, p.EMAIL, p.MOBILE_PHONE
    from read_csv('domains.csv') d
    join people p on split_part(p.EMAIL, '@', 2) = lower(d.domain)
  ) to 'emails.csv'
""")

Email Finder, one person from a name and a domain:

# One person, from a name and a domain
duckdb.sql("""
  select EMAIL, CURRENT_JOB_TITLE
  from people
  where FULL_NAME ilike 'jane doe' and split_part(EMAIL, '@', 2) = 'acme.com'
""").show()

No credit is spent, whatever the number of rows. What the file doesn't hold, these queries won't find: a company outside the U.S., one of more than 500 employees (the free file's limit), a person it hasn't got. That's where Hunter's search of the web comes in. More queries, by state, industry and title: build a free B2B leads list with SQL.

• Finds an email at any domain, worldwide, from a name or a LinkedIn handle, and says where on the web it was found.
• Verifies the emails you bring, one by one or in bulk.
• Sends your cold emails: sequences from your own mailboxes, with tracking and A/B tests.
• Works where you do: browser extensions, a Google Sheets add-on, CRM integrations and an MCP server.

Datacircle sells data, not a prospecting tool. If you look up one person at a time across the world, Hunter does that; if you want the emails of U.S. companies by the hundred thousand, download them. Then send each LinkedIn URL to the LinkedIn profile API for the whole profile, at $0.00125 a profile found. Every vendor's price per 1,000 people, Hunter's included: B2B data API pricing compared; what each tool's free plan gives: free B2B database.

The free file is on your dashboard once you sign up with your work email, with the $5 credit and your API key.