Email Validation API

Easily validate any email addresses.
High Accuracy
Our email validation tool performs advanced real-time checks that give you high accuracy.
Easy to integrate
Using our simple HTTP API, verify any email address at collection points.
Fast verification
Our system runs millions of parallel validations. Clean thousands of emails in few minutes.
Well documented
Our API reference documentation gives you everything about Real Time API

Real-time Email Verification

Easily integrate validTo with your website, web application or any marketing platform. Our email verification API can be used to validate email addresses in real-time. It takes only a few minutes and requires no technical skills.
curl --request POST \{your_api_key}' \
     --header 'Accept: application/json' \
     --header 'Content-Type: application/json' \
     --data '
     "auto_verify": true,
     "local_file": "@/mailing-list.csv"
const fetch = require('node-fetch');

const url = '{your_api_key}';
const options = {
  method: 'POST',
  headers: {Accept: 'application/json', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    auto_verify: true,
    local_file: '@/mailing-list.csv'

fetch(url, options)
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error('error:' + err));

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', '{your_api_key}', [
  'body' => '{"auto_verify":true,"local_file":"@/mailing-list.csv"}',
  'headers' => [
    'Accept' => 'application/json',
    'Content-Type' => 'application/json',

echo $response->getBody();
require 'uri'
require 'net/http'

url = URI("{your_api_key}")

http =, url.port)

request =
request["Accept"] = 'application/json'
request["Content-Type"] = 'application/json'
request.body = "{\"auto_verify\":true,\"local_file\":\"@/mailing-list.csv"}"

response = http.request(request)
puts response.read_body
import requests

url = "{your_api_key}"

payload = {
    "auto_verify": True,
    "local_file": "@/mailing-list.csv"
headers = {
    "Accept": "application/json",
    "Content-Type": "application/json"

response = requests.request("POST", url, json=payload, headers=headers)


Bulk Email Validation API

Clean all new email addresses before they are added to your lists to improve your sender reputation and avoid email deliverability issues. Use our bulk email validation API to clean whole lists in a single call.

Frequently Asked Questions

Below we have listed some frequently asked questions about validTo API
Please find the full documentation for the API in API Docs.
You can make up to 120 requests per minute to the API endpoint.
Login to your validTo app and under API, you can generate your api key.
No. In a single plan, you can perform bulk email verification, single email verification and API email verification.
Still have unanswered questions? Get in touch

Start Cleaning Email Lists

Reduce hard bounces. Build sender reputation. Improve email delivery.

Get 100 free verification credits, no monthly subscription & no credit card necessary