What email patterns are detected?

Common patterns include: first.last@, f.last@, first@, last.first@, first_last@, and more. All detected variants are returned with their usage percentage.

How accurate is the pattern detection?

Patterns are computed from verified email addresses in our database. The percentage reflects the actual distribution across known contacts at the domain.

Can a company have multiple patterns?

Yes. Many companies use more than one email format. The API returns all detected patterns ranked by frequency.

How many credits per request?

1 credit per email format request.

How can I use this data?

Use the dominant pattern to generate email addresses for prospects, validate guessed addresses, or enrich your CRM data with predicted formats.

What SDKs are available?

13 official SDKs: C#, Dart, Deno, Elixir, Go, Lua, Node.js, Perl, PHP, Python, R, Ruby and Rust.

// get /v1/email-format

Email Format API

Detect the email format patterns used by any company domain. Returns all detected patterns with their percentage distribution so you can predict employee addresses.

Get free API key API reference

1 email count credit

// api console

Example response from the API reference

[0].format: {first}
[0].percentage: 66

// 01 · request

Email Format is one HTTPS request

Send the parameters with your key and secret. Every SDK, the CLI and the MCP server make this same call.

GET/email-formatParameter

domainrequired: Company domain

GET /email-format

curl "https://api.tomba.io/v1/email-format?domain=piedpiper.com" \
  -H "X-Tomba-Key: $TOMBA_API_KEY" \
  -H "X-Tomba-Secret: $TOMBA_SECRET_KEY"

const res = await fetch("https://api.tomba.io/v1/email-format?domain=piedpiper.com", {
  headers: {
    "X-Tomba-Key": process.env.TOMBA_API_KEY,
    "X-Tomba-Secret": process.env.TOMBA_SECRET_KEY
  }
});
const { data } = await res.json();

import os, requests

res = requests.get(
    "https://api.tomba.io/v1/email-format?domain=piedpiper.com",
    headers={
        "X-Tomba-Key": os.environ["TOMBA_API_KEY"],
        "X-Tomba-Secret": os.environ["TOMBA_SECRET_KEY"],
    },
)
data = res.json()["data"]

// 02 · response

What comes back

JSON, the same in every language. Fields Tomba doesn't know are null, never guessed.

GET/email-formatField

data[].formatstring: Pattern such as {first}.{last}
data[].percentageinteger: Share of the company's addresses

GET /email-format

200 OK· 1 email count credit

{
  "data": [
    {
      "format": "{first}",
      "percentage": 66
    },
    {
      "format": "{first}.{last}",
      "percentage": 34
    }
  ]
}

// 03 · cost and limits

What a call costs

A call is charged only under the condition below. Rate limits depend on your plan.

// cost

1email count credit

Charged when: Every successful call, including an empty result.

Errors, 429 and 451 responses, and the same request again within your usage window cost nothing.

How credits work

// rate limits

Requests per second / minute / day

	Free	Basic	Growth	Pro
Search, finder, similar, technology	1 / 2 / 5	3 / 50 / 500	5 / 80 / 1,000	8 / 150 / 4,000
Email verifier	1 / 2 / 10	2 / 40 / 500	3 / 60 / 1,000	5 / 100 / 4,000

Pro Plus, Scale and credit packs of 50,000 or more: no limit on these endpoints. Enterprise: no per-second or per-minute limit, 100,000 requests a day. Daily limits reset at 00:00 UTC. Rate limits

// faq

Email Format API Questions

Still have questions? Visit the help center

const res = await fetch("https://api.tomba.io/v1/email-finder?domain=piedpiper.com&first_name=Richard&last_name=Hendricks", { headers: { "X-Tomba-Key": process.env.TOMBA_API_KEY, "X-Tomba-Secret": process.env.TOMBA_SECRET_KEY } }); const { data } = await res.json();

import os, requests res = requests.get( "https://api.tomba.io/v1/email-finder?domain=piedpiper.com&first_name=Richard&last_name=Hendricks", headers={ "X-Tomba-Key": os.environ["TOMBA_API_KEY"], "X-Tomba-Secret": os.environ["TOMBA_SECRET_KEY"], }, ) data = res.json()["data"]

{ "data": { "email": "richard@piedpiper.com", "first_name": "Richard", "last_name": "Hendricks", "full_name": "Richard Hendricks", "website_url": "piedpiper.com", "company": "Pied Piper", "pattern": "{first}", "department": "executive", "type": "personal", "position": "CEO", "country": "US", "gender": "male", "twitter": null, "linkedin": "https://www.linkedin.com/in/richard-hendricks", "score": 100, "accept_all": false, "phone_number": true, "verification": { "date": "2025-01-15T10:32:00+01:00", "status": "valid" }, "sources": [ { "uri": "https://piedpiper.com/blog/engineering", "website_url": "piedpiper.com", "extracted_on": "2024-06-01T09:14:07+01:00", "last_seen_on": "2025-01-10T17:02:44+01:00", "still_on_page": true } ], "phone_data": [] } }

Email Format API

Email Format is one HTTPS request

What comes back

What a call costs

Related endpoints

Email Format API Questions

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