Contact Dedupe and Fuzzy Match API

API ID 14605

Find duplicate contacts and leads with fuzzy name, email, phone and address matching, including nickname support. JSON or CSV in, duplicate clusters out.

62 ms avg response

API Documentation

Endpoints

Request
Find duplicates in a list of up to 250 contact records per call. Send JSON {"records":[...], "threshold":0.85, "weights":{...}} and get back duplicate groups, scored pairs with match reasons, and a merged survivor record per group. Or send CSV (Content-Type: text/csv) and get the same CSV back with dup_group, is_duplicate, master_row and match_score columns; add ?output=unique for a deduplicated file and ?threshold= to tune strictness.
Endpoint ID: 37456
POST https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37456/dedupe+contacts
INPUT PARAMETERS

Dedupe Contacts — Endpoint Features

Object Description
Request Body Required Json

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

API EXAMPLE RESPONSE
JSON
{
    "threshold": 0.85,
    "input_count": 3,
    "unique_count": 2,
    "duplicate_count": 1,
    "groups": [
        {
            "group_id": 0,
            "indexes": [
                0,
                1
            ],
            "master_index": 0
        }
    ],
    "pairs": [
        {
            "a": 0,
            "b": 1,
            "score": 0.9,
            "reasons": [
                "phone_match",
                "name_match"
            ]
        }
    ],
    "merged": [
        {
            "name": "Bob Smith",
            "email": "[email protected]",
            "phone": "(555) 123-4567"
        },
        {
            "name": "Alice Jones",
            "email": "[email protected]"
        }
    ],
    "comparisons": 1,
    "skipped_blocks": 0,
    "group_of": [
        0,
        0,
        1
    ]
}
Dedupe Contacts — CODE SNIPPETS

curl --location --request POST 'https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37456/dedupe+contacts' --header 'Authorization: Bearer YOUR_API_KEY' 

--data-raw '{"records":[{"name":"Bob Smith","email":"[email protected]","phone":"(555) 123-4567"},{"name":"Smith, Robert","email":"[email protected]","phone":"555.123.4567"},{"name":"Alice Jones","email":"[email protected]"}]}'

    
Request
Compare two contact records and decide whether they are the same person. Returns an overall weighted score, per-field scores, match reasons and an is_duplicate flag at your threshold (default 0.85). Optional weights let you emphasize fields such as email, phone, name, address or any custom field.
Endpoint ID: 37458
POST https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37458/compare+two+contacts
INPUT PARAMETERS

Compare Two Contacts — Endpoint Features

Object Description
Request Body Required Json

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

API EXAMPLE RESPONSE
JSON
{
    "score": 0.916,
    "field_scores": {
        "phone": 1,
        "name": 0.789
    },
    "compared_fields": [
        "phone",
        "name"
    ],
    "reasons": [
        "phone_match"
    ],
    "is_duplicate": true,
    "threshold": 0.85
}
Compare Two Contacts — CODE SNIPPETS

curl --location --request POST 'https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37458/compare+two+contacts' --header 'Authorization: Bearer YOUR_API_KEY' 

--data-raw '{"a":{"name":"Jon Smyth","phone":"555-123-4567"},"b":{"name":"John Smith","phone":"+1 555 123 4567"}}'

    
Request
Raw string similarity between two texts (up to 1,000 characters each): Levenshtein distance and ratio, Jaro-Winkler and token Jaccard. Text is normalized (lowercase, punctuation and company suffixes) unless "normalize": false.
Endpoint ID: 37460
POST https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37460/string+similarity
INPUT PARAMETERS

String Similarity — Endpoint Features

Object Description
Request Body Required Json

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

API EXAMPLE RESPONSE
JSON
{
    "a": "acme corporation",
    "b": "acme corp",
    "levenshtein_distance": 7,
    "levenshtein_ratio": 0.563,
    "jaro_winkler": 0.913,
    "token_jaccard": 0.333
}
String Similarity — CODE SNIPPETS

curl --location --request POST 'https://zylalabs.com/api/14605/contact+dedupe+and+fuzzy+match+api/37460/string+similarity' --header 'Authorization: Bearer YOUR_API_KEY' 

--data-raw '{"a":"Acme Corporation","b":"ACME Corp."}'

    

API Access Key & Authentication

After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the Contact Dedupe and Fuzzy Match API simply include your bearer token in the Authorization header.

Headers
Header Description
Authorization Required Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.

No long-term commitment. Upgrade, downgrade, or cancel anytime.

Starts at
$10,000/Year


  • Custom Volume
  • Custom Rate Limit
  • Specialized Customer Support
  • Real-Time API Monitoring

Overview

Find duplicate contacts and leads with fuzzy name, email, phone and address matching, including nickname support. JSON or CSV in, duplicate clusters out.

Contact Dedupe and Fuzzy Match API FAQs

The "Dedupe Contacts" endpoint returns duplicate groups, scored pairs with match reasons, and merged records. The "Compare Two Contacts" endpoint provides a weighted score, field scores, match reasons, and a duplicate flag. The "String Similarity" endpoint returns similarity metrics like Levenshtein distance and Jaro-Winkler scores.

Key fields include "groups" (duplicate clusters), "pairs" (matched records with scores), "merged" (consolidated records), "score" (overall match score), and "field_scores" (individual field match scores) across the endpoints.

Parameters include "records" (for contact data), "threshold" (to set match strictness), and "weights" (to emphasize specific fields). The "String Similarity" endpoint accepts "normalize" to control text normalization.

Typical use cases include cleaning contact databases, merging duplicate leads, validating contact information, and enhancing CRM data quality. Businesses can leverage this API to improve customer outreach and data accuracy.

Data accuracy is maintained through fuzzy matching algorithms that account for variations in names, emails, and phone numbers. The API uses weighted scoring to prioritize more reliable fields, ensuring robust matching results.

Users can analyze the "groups" to identify duplicates, use "pairs" to understand match reasons, and leverage "merged" records for a unified contact profile. This helps in streamlining data management and improving customer interactions.

It matches contact records on name (nicknames, accents, "Last, First" order), email (case, +tags, Gmail dots), phone (any US format) and address, using weighted Jaro-Winkler, Levenshtein and token scoring.

POST /v1/dedupe accepts up to 250 records per call. Larger lists should be split into batches; requests above the limit return a 413 batch_too_large error.

Yes. Send a CSV with Content-Type: text/csv to /v1/dedupe and receive the same CSV back with dup_group, is_duplicate, master_row and match_score columns. Add ?output=unique to get only unique rows.

Yes. Set "threshold" (default 0.85) to make matching stricter or looser, and pass "weights" to emphasize fields such as email, phone, name or address.

General FAQs

To obtain your API key, first sign in to your account and navigate to the API you want to use. From the API's Pricing section, choose a plan and complete the subscription process. Once subscribed, return to the API page and you will see your API Access Key displayed at the top of the documentation page. You can use this key to authenticate your requests.

You can’t switch APIs during the free trial. If you subscribe to a different API, your trial will end and the new subscription will start as a paid plan.

The free trial lasts for 7 days and allows you to make up to 50 API requests.

No, the free trial is available only once, so we recommend using it on the API that interests you the most. Most of our APIs offer a free trial, but some may not include this option.

Yes. If the API offers a free trial, you will see a "Free 7-Day Trial" option in its Pricing section. The trial lasts for 7 days and allows up to 50 API requests, enabling you to evaluate the API before subscribing to a paid plan.

Zyla API Hub is like a big store for APIs, where you can find thousands of them all in one place. We also offer dedicated support and real-time monitoring of all APIs. Once you sign up, you can pick and choose which APIs you want to use. Just remember, each API needs its own subscription. But if you subscribe to multiple ones, you'll use the same key for all of them, making things easier for you.

Prices are listed in USD (United States Dollar), EUR (Euro), CAD (Canadian Dollar), AUD (Australian Dollar), and GBP (British Pound). We accept all major debit and credit cards. Our payment system uses the latest security technology and is powered by Stripe, one of the world's most reliable payment companies. If you have any trouble paying by card, just contact us at [email protected]

Additionally, if you already have an active subscription in any of these currencies (USD, EUR, CAD, AUD, GBP), that currency will remain for subsequent subscriptions. You can change the currency at any time as long as you don't have any active subscriptions.
The local currency shown on the pricing page is based on the country of your IP address and is provided for reference only. The actual prices are in USD (United States Dollar). When you make a payment, the charge will appear on your card statement in USD, even if you see the equivalent amount in your local currency on our website. This means you cannot pay directly with your local currency.
Occasionally, a bank may decline the charge due to its fraud protection settings. We suggest reaching out to your bank initially to check if they are blocking our charges. Also, you can access the Billing Portal and change the card associated to make the payment. If these does not work and you need further assistance, please contact our team at [email protected]
Prices are determined by a recurring monthly or yearly subscription, depending on the chosen plan.
API calls are deducted from your plan based on successful requests. Each plan comes with a specific number of calls that you can make per month. Only successful calls, indicated by a Status 200 response, will be counted against your total. This ensures that failed or incomplete requests do not impact your monthly quota.
Zyla API Hub works on a recurring monthly subscription system. Your billing cycle will start the day you purchase one of the paid plans, and it will renew the same day of the next month. So be aware to cancel your subscription beforehand if you want to avoid future charges.
To upgrade your current subscription plan, simply go to the pricing page of the API and select the plan you want to upgrade to. The upgrade will be instant, allowing you to immediately enjoy the features of the new plan. Please note that any remaining calls from your previous plan will not be carried over to the new plan, so be aware of this when upgrading. You will be charged the full amount of the new plan.
To check how many API calls you have left for the current month, refer to the 'X-Zyla-API-Calls-Monthly-Remaining' field in the response header. For example, if your plan allows 1,000 requests per month and you've used 100, this field in the response header will indicate 900 remaining calls.

You can monitor your API usage through the response headers included with every request:

x-zyla-api-calls-monthly-used: Shows the total number of API requests you have used during the current billing period.
x-zyla-api-calls-monthly-remaining: Shows the number of API requests you have remaining for the current billing period.

The 'X-Zyla-RateLimit-Reset' header shows the number of seconds until your rate limit resets. This tells you when your request count will start fresh. For example, if it displays 3,600, it means 3,600 seconds are left until the limit resets.

Yes, you can cancel your subscription at any time. Simply go to the Pricing section of the API you're subscribed to and click the "Unsubscribe" button.

Please note that upgrades, downgrades, and cancellations take effect immediately. Once your subscription is canceled, access to the service will end immediately, regardless of any remaining API calls in your quota.

After 7 days, you will be charged the full amount for the plan you were subscribed to during the trial. Therefore, it's important to cancel before the trial period ends. Refund requests for forgetting to cancel on time are not accepted.
When you subscribe to an API free trial, you can make up to 50 API calls. If you wish to make additional API calls beyond this limit, the API will prompt you to perform an "Start Your Paid Plan." You can find the "Start Your Paid Plan" button in your profile under Subscription -> Choose the API you are subscribed to -> Pricing tab.
You can contact us through our chat channel to receive immediate assistance. We are always online from 8 am to 5 pm (EST). If you reach us after that time, we will get back to you as soon as possible. Additionally, you can contact us via email at [email protected]

Please have a look at our Refund Policy: https://zylalabs.com/terms#refund


Related APIs