WebSDR receivers and beacons
WebSDR receivers, KiwiSDR and OpenWebRX: listen to the bands from receivers around the world right in your browser, check your own signal and see which NCDXF/IARU beacon is transmitting now to know at once where the band is open.
NCDXF/IARU beacons: who is on the air now i
Each transmission: callsign in CW at 22 words per minute and four one-second dashes at 100 W, 10 W, 1 W and 0.1 W. If you also hear the weakest dashes, propagation is very good.
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Each transmission: callsign in CW at 22 words per minute and four one-second dashes at 100 W, 10 W, 1 W and 0.1 W. If you also hear the weakest dashes, propagation is very good.18 beacons around the world transmit in turn, 10 seconds each, on five HF frequencies; the cycle repeats every 3 minutes, day and night. Listen with your radio or a WebSDR: if you hear the beacon, the band is open towards that area.
UTC time --:--:--
| Frequency | On the air now | From | Distance · heading | Next | In |
|---|---|---|---|---|---|
| 14.100 MHz | — | — | — | — | — |
| 18.110 MHz | — | — | — | — | — |
| 21.150 MHz | — | — | — | — | — |
| 24.930 MHz | — | — | — | — | — |
| 28.200 MHz | — | — | — | — | — |
Frequencies: 14.100 · 18.110 · 21.150 · 24.930 · 28.200 MHz, CW. The schedule starts at the beginning of every hour (minute 00, second 00).
The 18 beacons
| No. | Callsign | Location | Locator | Status |
|---|---|---|---|---|
| 1 | 4U1UN | New York (UN) | FN30as | active |
| 2 | VE8AT | Inuvik, Canada | CP38gh | active |
| 3 | W6WX | Mt. Umunhum, USA | CM97bd | active |
| 4 | KH6RS | Maui, Hawaii | BL10ts | active |
| 5 | ZL6B | Masterton, New Zealand | RE78tw | active |
| 6 | VK6RBP | Rolystone, Australia | OF87av | active |
| 7 | JA2IGY | Mt. Asama, Japan | PM84jk | active |
| 8 | RR9O | Novosibirsk, Russia | NO14kx | active |
| 9 | VR2B | Hong Kong | OL72bg | reported off by NCDXF |
| 10 | 4S7B | Colombo, Sri Lanka | MJ96wv | active |
| 11 | ZS6DN | Pretoria, South Africa | KG33xi | active |
| 12 | 5Z4B | Kikuyu, Kenya | KI88hr | active |
| 13 | 4X6TU | Tel Aviv, Israel | KM72jb | active |
| 14 | OH2B | Lohja, Finland | KP20eh | active |
| 15 | CS3B | São Jorge, Madeira | IM12jt | active |
| 16 | LU4AA | Buenos Aires, Argentina | GF05tj | active |
| 17 | OA4B | Lima, Peru | FH17mw | active |
| 18 | YV5B | Caracas, Venezuela | FK60nd | reported off by NCDXF |
See also: Band Conditions →
WebSDR receivers and other web receivers: where to find them
Three families of receivers you use from the browser, with nothing to install. The official lists show which are online now.
WebSDR
Software by Pieter-Tjerk de Boer, PA3FWM: many users listen to and tune the same receiver at once. The best known is the University of Twente one, which receives the whole shortwave spectrum.
WebSDR.org (PA3FWM) ↗
WebSDR University of Twente ↗
ARRL — WebSDR (PA3FWM) ↗
KiwiSDR
Shortwave SDR receiver with GPS; many are public. It includes a scanner for the NCDXF/IARU beacons.
OpenWebRX
Multi-user receiver usable from any browser, with no software to install.
Receiverbook
List and map of web receivers (OpenWebRX, WebSDR, KiwiSDR) filterable by type and band: the quickest way to find one near or far.
Listening to your own signal
A distant receiver tells you how your signal really gets out: useful to test an antenna or compare two settings.
Choose the receiver
On HF pick one at least a few hundred kilometres away: too close and it hears you by ground wave, which says nothing about propagation.
Tune before you transmit
Set frequency and mode (USB, LSB, CW) on the web receiver and check the frequency is clear.
Transmit briefly and identify
A few seconds, always with your callsign, as for any on-air test.
Allow for the delay
Web audio arrives a few seconds late: listen after you stop transmitting.
Compare
Repeat the test with another antenna or power level and note the web receiver’s S-meter.
Read the full guide: How to Transmit and Check Your Radio Signal with a WebSDR →
Good practice and common problems
The receiver is shared
On many web receivers other users are listening at the same time: do not leave the session open if you are not using it and, on KiwiSDRs, remember that channels are limited.
No sound
The browser blocks audio until you click on the page: press start or the waterfall. Also check volume and mode (USB/LSB).
The receiver does not respond or is slow
Many are run by radio amateurs on home connections: try another receiver from the list.
The web signal differs from your radio
Every receiver has its own antenna, local noise and location: always compare several receivers.
Sources: NCDXF — International Beacon Project, NCDXF — Beacon locations, NCDXF — Transmission schedule, NCDXF — Web receivers, WebSDR.org (PA3FWM), WebSDR University of Twente, KiwiSDR, OpenWebRX, Receiverbook, ARRL — WebSDR (PA3FWM). Sources consulted on 18 October 2026. Links open on the publisher’s website. RadioMeteo does not run the receivers listed.
Articles on WebSDR and web receivers
RadioMeteo articles on WebSDR, KiwiSDR, OpenWebRX and beacons appear here automatically when they are published.
How to Transmit and Check Your Radio Signal with a WebSDR
A WebSDR signal test checks whether a remote receiver can hear your transmission. Learn how to choose a receiver, tune it and interpret the…
Read the article →