Unit Converter API

Overview

To use Unit Converter, you need an API key. You can get one by creating a free account and visiting your dashboard.

GET Endpoint

https://api.apiverve.com/v1/unitconverter

Example

How to call the Unit Converter API in different programming languages.

curl -X GET \
  "https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg" \
  -H "X-API-Key: your_api_key_here"

const response = await fetch('https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg', {
  method: 'GET',
  headers: {
    'X-API-Key': 'your_api_key_here',
    'Content-Type': 'application/json'
  }
});

const data = await response.json();
console.log(data);

import requests

headers = {
    'X-API-Key': 'your_api_key_here',
    'Content-Type': 'application/json'
}

response = requests.get('https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg', headers=headers)

data = response.json()
print(data)

package main

import (
    "fmt"
    "io"
    "net/http"

)

func main() {
    req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg", nil)

    req.Header.Set("X-API-Key", "your_api_key_here")
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, _ := io.ReadAll(resp.Body)
    fmt.Println(string(body))
}

{
  "status": "ok",
  "error": null,
  "data": {
    "result": {
      "result": 45.36,
      "from": "100 lb",
      "to": "kg"
    },
    "unitDefinitions": {
      "from": {
        "abbr": "lb",
        "measure": "mass",
        "system": "imperial",
        "singular": "Pound",
        "plural": "Pounds"
      },
      "to": {
        "abbr": "kg",
        "measure": "mass",
        "system": "metric",
        "singular": "Kilogram",
        "plural": "Kilograms"
      }
    }
  }
}

Authentication

The Unit Converter API requires authentication via API key. Include your API key in the request header:

X-API-Key: your_api_key_here

Learn more about authentication →

Interactive API Playground

Test the Unit Converter API directly in your browser with live requests and responses.

Parameters

The following parameters are available for the Unit Converter API:

Response

The Unit Converter API returns responses in JSON, XML, YAML, and CSV formats. The JSON response is shown in the Example section above; alternative formats below.

Other Response Formats

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <status>ok</status>
  <error xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
  <data>
    <result>
      <result>45.36</result>
      <from>100 lb</from>
      <to>kg</to>
    </result>
    <unitDefinitions>
      <from>
        <abbr>lb</abbr>
        <measure>mass</measure>
        <system>imperial</system>
        <singular>Pound</singular>
        <plural>Pounds</plural>
      </from>
      <to>
        <abbr>kg</abbr>
        <measure>mass</measure>
        <system>metric</system>
        <singular>Kilogram</singular>
        <plural>Kilograms</plural>
      </to>
    </unitDefinitions>
  </data>
</response>

status: ok
error: null
data:
  result:
    result: 45.36
    from: 100 lb
    to: kg
  unitDefinitions:
    from:
      abbr: lb
      measure: mass
      system: imperial
      singular: Pound
      plural: Pounds
    to:
      abbr: kg
      measure: mass
      system: metric
      singular: Kilogram
      plural: Kilograms

Response Structure

All API responses follow a consistent structure with the following fields:

Learn more about response formats →

Response Data Fields

When the request is successful, the data object contains the following fields:

Headers

Only X-API-Key is required. Optional headers include Accept for response format negotiation (JSON, XML, or YAML), User-Agent, and X-Request-ID for request tracing. See all request headers →

GraphQL AccessALPHA

Access Unit Converter through GraphQL to combine it with other API calls in a single request. Query only the unit converter data you need with precise field selection, and orchestrate complex data fetching workflows.

Credit Cost: Each API called in your GraphQL query consumes its standard credit cost.

POST https://api.apiverve.com/v1/graphql

query {
  unitconverter(
    input: {
      value: 100
      from: "lb"
      to: "kg"
    }
  ) {
    result {
      result
      from
      to
    }
    unitDefinitions {
      from {
        abbr
        measure
        system
        singular
        plural
      }
      to {
        abbr
        measure
        system
        singular
        plural
      }
    }
  }
}

Note: Authentication is handled via the x-api-key header in your GraphQL request, not as a query parameter.

CORS Support

The Unit Converter API accepts cross-origin requests from any origin, so it can be called directly from browser-based applications without a proxy. See CORS support →

Rate Limiting

Unit Converter requests are throttled per minute on the Free plan and unthrottled on paid plans. Exceeding the limit returns 429 Too Many Requests; rate-limit usage is reported in the X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset response headers. See per-plan limits and best practices →

Error Codes

The Unit Converter API uses standard HTTP status codes — 200 on success, 400 for invalid parameters, 401 for missing or invalid keys, 403 for insufficient credits, 429 for rate-limit exhaustion, and 500/503 for server-side issues. Each error response includes an X-Request-ID header you can quote when contacting support. See full error handling guide →

SDKs for Unit Converter

Official Unit Converter packages on npm, PyPI, NuGet, and JitPack — plus a Postman collection and an OpenAPI spec. See the SDK guide →

JitPack

No-Code Integrations

Unit Converter works with Zapier, Make, Pipedream, n8n, and Power Automate using the same API key. See setup guides →

Zapier

Make

Pipedream

n8n

Power Automate

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