Build an Indian address form with a free PIN Code API

The problem

Asking users to type their district and state by hand is slow and error-prone — people misspell districts, pick the wrong state, or leave fields blank. In India the 6-digit PIN code already encodes the post office, district and state, so you can auto-fill those the moment the user finishes typing the pincode.

The endpoint

Use the free PIN Code API. No key, no signup:

GET https://api.apibharat.com/v1/pincode/{pincode}

Response is JSON (application/json). A valid pincode is 6 digits and cannot start with 0.

A real request

curl https://api.apibharat.com/v1/pincode/560001

{
  "success": true,
  "data": {
    "pincode": "560001",
    "district": "Bengaluru",
    "state": "Karnataka",
    "post_offices": [
      { "office_name": "Bangalore GPO", "region": "Bengaluru", "circle": "Karnataka" }
    ]
  },
  "message": "PIN code details found"
}

Wiring it into a form

Listen for a complete 6-digit pincode, validate the format client-side first, then call the API and fill the district and state:

<input id="pincode" maxlength="6" inputmode="numeric" placeholder="Pincode">
<input id="district" placeholder="District" readonly>
<input id="state" placeholder="State" readonly>

<script>
const pin = document.getElementById("pincode");
pin.addEventListener("input", async () => {
  const v = pin.value.trim();
  // Validate before spending a request.
  if (!/^[1-9][0-9]{5}$/.test(v)) return;

  const res = await fetch(`https://api.apibharat.com/v1/pincode/${v}`);
  const json = await res.json();
  if (!json.success) {
    // 404 = not found, 422 = bad format
    document.getElementById("district").value = "";
    document.getElementById("state").value = "";
    return;
  }
  document.getElementById("district").value = json.data.district;
  document.getElementById("state").value = json.data.state;
});
</script>

Validation & errors

• Format: check /^[1-9][0-9]{5}$/ before calling — it saves a round trip and gives instant feedback.
• 422 Unprocessable: the pincode isn't 6 digits. Show an inline "enter a valid 6-digit pincode" message.
• 404 Not found: a well-formed pincode with no record. Let the user type district/state manually as a fallback.
• One pincode can map to several post offices — the post_offices array lists them all if you want a locality dropdown.

Try it

Prefer to test without code? Use the PIN Code Finder (it also supports reverse search by area name), or read the full Pincode API reference.