Locator to coordinates
API · /maidenhead-api
Maidenhead Locator API
healthy
4,890 Subscribers
Convert between latitude/longitude and the Maidenhead Locator System — the grid-square "QTH locator" (like JN58td or IO91wm) used by amateur radio, APRS and contesting to describe a position compactly. The encode endpoint turns a latitude and longitude into a locator at 4-, 6-, 8- or 10-character precision. The decode endpoint turns a locator back into the centre coordinates, the south-west corner and the size of the grid square. The distance endpoint gives the great-circle distance (kilometres and miles) and bearing between the centres of two locators — the classic "how far and which way is that station". Everything is computed locally and deterministically, so it is instant and private. Ideal for amateur-radio and APRS tools, contest logging, antenna aiming, and grid-based mapping. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the Maidenhead system; for Plus Codes, MGRS, UTM and DMS use a geo-convert API and for precise geodesic distance use a geodesy API.
api.oanor.com/maidenhead-api
API health
healthy- Uptime
- 100.00%
- Server probes · 24h
- Avg latency
- 95 ms
- Server probes · 24h
- Subscribers
- 4,890
- active
- Total calls
- 44
- last 7 days
Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 8,535 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- 8,535 calls/month
- 2 req/sec
- Encode + decode + distance
- No credit card
Starter
€10.05 /month
- 18,050 calls / month
- 8 requests / second
- Hard cap (429 above quota, no overage)
- 18.05k calls/month
- 8 req/sec
- 4/6/8/10-char precision
- Email support
Pro
€29.95 /month
- 231,500 calls / month
- 20 requests / second
- Hard cap (429 above quota, no overage)
- 231.5k calls/month
- 20 req/sec
- Ham-radio / APRS pipelines
- Priority support
Mega
€67.95 /month
- 1,200,000 calls / month
- 50 requests / second
- Hard cap (429 above quota, no overage)
- 1.2M calls/month
- 50 req/sec
- Platform scale
- Dedicated SLA
Built by
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api.oanor.com/antenna-api
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Frequently asked questions
Quick answers about pricing, quotas, and integration.
How do I get an API key for Maidenhead Locator API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Maidenhead Locator API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Maidenhead Locator API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Maidenhead Locator API cost?
Maidenhead Locator API has a free tier with 100 calls / month. Paid plans start at €10.05 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Maidenhead Locator API GDPR-compliant?
All requests to Maidenhead Locator API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.
Pick an endpoint from the list on the left to see its details and try it.
Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/maidenhead-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."const res = await fetch("https://api.oanor.com/maidenhead-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();$ch = curl_init("https://api.oanor.com/maidenhead-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);import requests
r = requests.get(
"https://api.oanor.com/maidenhead-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())Ratings
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