Convert coordinates across Decimal Degrees (DD)
Convert coordinates across Decimal Degrees (DD), DMS, UTM, and Geohash with GeoJSON & WKT outputs
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
Response
{
"coordinates": {
"dd": {
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"lat": 51.1079,
"lng": 17.0385
},
"dms": {
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"lat": {
"deg": 33,
"dir": "<dir>",
"min": 10,
"sec": 1.1
},
"lng": {
"deg": 33,
"dir": "<dir>",
"min": 10,
"sec": 1.1
}
},
"geoJson": {
"coordinates": [
3.9,
0.8
],
"type": "standard"
},
"geohash": {
"boundingBox": {
"maxLat": 51.1079,
"maxLng": 17.0385,
"minLat": 51.1079,
"minLng": 17.0385
},
"code": "ABC-123",
"precision": 18
},
"utm": {
"easting": 7.0,
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"hemisphere": "<hemisphere>",
"northing": 7.6,
"zone": 31
},
"wkt": "<wkt>"
},
"sourceFormat": "json",
"status": "success",
"tokensDeducted": 1
}What it does
Convert coordinates across Decimal Degrees (DD), DMS, UTM, and Geohash with GeoJSON & WKT outputs
Request
Body
| Field | Type | Required | Description |
|---|---|---|---|
coordinates | string | object | yes | Coordinates as string ("50.32, 19.18", "u27mb1x", DMS string) or object ({ lat: 50.32, lng: 19.18 } or { zone: 34, easting, northing }). |
from | enum | no | Optional explicit source coordinate format. One of: auto, dd, dms, utm, geohash. |
geohashPrecision | integer | no | Geohash output length precision (1 to 12 characters). |
Example request
{
"coordinates": "51.1079, 17.0385",
"from": "auto",
"geohashPrecision": 9
}Response
| Field | Type | Description |
|---|---|---|
coordinates | object | |
↳ dd | object | |
↳ dms | object | |
↳ geoJson | object | |
↳ geohash | object | |
↳ utm | object | |
↳ wkt | string | |
sourceFormat | string | |
status | string | |
tokensDeducted | integer |
Example response
{
"coordinates": {
"dd": {
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"lat": 51.1079,
"lng": 17.0385
},
"dms": {
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"lat": {
"deg": 33,
"dir": "<dir>",
"min": 10,
"sec": 1.1
},
"lng": {
"deg": 33,
"dir": "<dir>",
"min": 10,
"sec": 1.1
}
},
"geoJson": {
"coordinates": [
3.9,
0.8
],
"type": "standard"
},
"geohash": {
"boundingBox": {
"maxLat": 51.1079,
"maxLng": 17.0385,
"minLat": 51.1079,
"minLng": 17.0385
},
"code": "ABC-123",
"precision": 18
},
"utm": {
"easting": 7.0,
"formatted": "PL61 1090 1014 0000 0712 1981 2874",
"hemisphere": "<hemisphere>",
"northing": 7.6,
"zone": 31
},
"wkt": "<wkt>"
},
"sourceFormat": "json",
"status": "success",
"tokensDeducted": 1
}Errors
Every error answers with the same envelope: an HTTP status, a machine code and a sentence.
400 | The body or a parameter failed validation. The details array names the field. |
401 | No key, a revoked key or a wrong header. Send x-api-key. |
402 | The wallet cannot cover this call. Top up or wait for the monthly grant. |
404 | The resource does not exist, or it is not yours. Both answer identically and cost nothing. |
429 | Over the per-minute quota of your tier. Back off and retry. |
5xx | Upstream refused or timed out. The call is not billed. |
Code
curl -X POST 'https://app.castomapi.com/v1/convert/geo' \
-H 'x-api-key: <your-api-key>' \
-H 'Content-Type: application/json' \
-d '{"coordinates": "51.1079, 17.0385", "from": "auto", "geohashPrecision": 9}'const res = await fetch('https://app.castomapi.com/v1/convert/geo', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"coordinates": "51.1079, 17.0385", "from": "auto", "geohashPrecision": 9})
});
const data = await res.json();
console.log(data);import { request } from 'node:https';
// Node 18+ has fetch built in
const res = await fetch('https://app.castomapi.com/v1/convert/geo', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"coordinates": "51.1079, 17.0385", "from": "auto", "geohashPrecision": 9})
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/convert/geo',
headers={'x-api-key': '<your-api-key>'},
json={"coordinates": "51.1079, 17.0385", "from": "auto", "geohashPrecision": 9},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/convert/geo');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
CURLOPT_POSTFIELDS => json_encode(['coordinates' => '51.1079, 17.0385', 'from' => 'auto', 'geohashPrecision' => 9]),
]);
$data = json_decode(curl_exec($ch), true);
print_r($data);Cost and limits
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
Rate limits per minute
| No key | 10 |
| Free | 60 |
| Pro | 300 |
| Enterprise | 1200 |
Questions
What does Convert coordinates across Decimal Degrees (DD) cost?
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
How do I authenticate?
Send your key in the x-api-key header. One key covers every metered endpoint; there is nothing to enable per endpoint.
Can I send an Authorization: Bearer token instead?
Not for a metered endpoint — those take the x-api-key header and nothing else. Bearer tokens belong to the account side: the dashboard and account APIs accept a JWT session, and castomapi-auth issues those through a standard OAuth2 handshake, with authorization code, client credentials and refresh grants. The auth service page covers it.
What are the limits?
10 requests a minute per IP with no key at all, 60 a minute on the free tier, 300 on Pro, 1200 on Enterprise. Above the no-key tier the quota is per account, across every endpoint.
OpenAPI: https://app.castomapi.com/docs/json