About Spothole

Spothole is a utility to aggregate "spots" from amateur radio DX clusters and xOTA spotting sites, and provide an open JSON API as well as a website to browse the data.

While there are several other web-based interfaces to DX clusters, and sites that aggregate spots from various outdoor activity programmes for amateur radio, Spothole differentiates itself by supporting a larger number of data sources, and by being "API first" rather than just providing a web front-end. This allows other software to be built on top of it.

The API is deliberately well-defined with an OpenAPI specification and API documentation. The API delivers spots in a consistent format regardless of the data source, freeing developers from needing to know how each individual data source presents its data.

Spothole itself is also open source, Public Domain licenced code that anyone can take and modify. The source code is here.

The software was written by Ian Renton, MØTRT and other contributors. Full details are available in the README file.

This server is running Spothole version 1.1-pre.

Using Spothole

There are a number of different ways to use Spothole, depending on what you want to do with it and your level of technical skill:

1. You can use it on the web, like you are (probably) doing right now. This is how most people use it, to look up spots and alerts, and make interesting QSOs.
2. If you are using an Android or iOS device, you can "install" it on your device. Spothole is a Progressive Web App, meaning it's not delivered through app stores, but if you open the page on Chrome (Android) or Safari (iOS) there will be an option in the menu to install it. It will then appear in your main app menu.
3. You can embed the web interface in another website to show its spots in a custom dashboard or the like. The usage is explained in more detail in the README file.
4. You can write your own client using the Spothole API, using the main Spothole instance to provide data, and do whatever you like with it. The README contains guidance on how to do this, and the full API docs are linked above. You can also find reference implementations in the form of Spothole's own web-based front end, plus my other two tools built on Spothole: Field Spotter and the QSO Map Tool.
5. If you want to run your own version of Spothole so you can customise the configuration, such as enabling sources that I disable on the main instance, you can do that too. The README contains not only advice on how to set up Spothole but how to get it auto-starting with systemd, using an nginx reverse proxy, and setting up HTTPS support with certbot.
6. Finally, you can of course download the source code and develop Spothole to meet your needs. Whether you contribute your changes back to the main repository is up to you. As usual, the README file contains some advice on the structure of the repository, and how to get started writing your own spot provider.

FAQ

"Spots"? "DX Clusters"? What does any of this mean?

This is a tool for amateur ("ham") radio users. Many amateur radio operators like to make contacts with others who are doing something more interesting than sitting in their home "shack", such as people in rarely-seen countries, remote islands, or on mountaintops. Such operators are often "spotted", i.e. when someone speaks to them, they will put the details such as their operating frequency into an online system, to let others know where to find them. A DX Cluster is one type of those systems. Most outdoor radio awards programmes, such as "Parks on the Air" (POTA) have their own websites for posting spots.

Spothole is an "aggregator" for those spots, so it checks lots of different services for data, and brings it all together in one place. So no matter what kinds of interesting spots you are looking for, you can find them here.

As well as spots, it also provides a similar feed of "alerts". This is where amateur radio users who are going to interesting places soon will announce their intentions.

What are "DX", "DE" and modes?

In amateur radio terminology, the "DX" contact is the "interesting" one that is using the frequency shown and looking for callers. They might be on a remote island or just in a local park, but either way it's interesting enough that someone has "spotted" them. The callsign listed under "DE" is the person who entered the spot of the "DX" operator. "Modes" are the type of communication they are using. For example you might see "CW" which is Morse Code, or voice "modes" like SSB or FM, or more exotic "data" modes which are used for computer-to-computer communication.

What data sources are supported?

Spothole can retrieve spots from: Telnet-based DX clusters, the Reverse Beacon Network (RBN), the APRS Internet Service (APRS-IS), POTA, SOTA, WWFF, GMA, WWBOTA, HEMA, Parks 'n' Peaks, ZLOTA, WOTA, the UK Packet Repeater Network, and any site based on the xOTA software by nischu.

Spothole can retrieve alerts from: NG3K, POTA, SOTA, WWFF, Parks 'n' Peaks, WOTA and BOTA.

Note that the server owner has not necessarily enabled all these data sources. In particular it is common to disable RBN, to avoid the server being swamped with FT8 traffic, and to disable APRS-IS and UK Packet Net so that the server only displays stations where there is likely to be an operator physically present for a QSO.

Between the various data sources, the following Special Interest Groups (SIGs) are supported: Parks on the Air (POTA), Summits on the Air (SOTA), Worldwide Flora & Fauna (WWFF), Global Mountain Activity (GMA), Worldwide Bunkers on the Air (WWBOTA), HuMPs Excluding Marilyns Award (HEMA), Islands on the Air (IOTA), Mills on the Air (MOTA), the Amateur Radio Lighthouse Socirty (ARLHS), International Lighthouse Lightship Weekend (ILLW), Silos on the Air (SIOTA), World Castles Award (WCA), New Zealand on the Air (ZLOTA), Keith Roget Memorial National Parks Award (KRMNPA), Wainwrights on the Air (WOTA), Beaches on the Air (BOTA), Worked All Britain (WAB), Worked All Ireland (WAI), and Toilets on the Air (TOTA).

As of the time of writing in November 2025, I think Spothole captures essentially all outdoor radio programmes that have a defined reference list, and almost certainly those that have a spotting/alerting API. If you know of one I've missed, please let me know!

Why can I filter spots by both SIG and Source? Isn't that basically the same thing?

Mostly, but not quite. While POTA spots generally come from the POTA source and so on, there are a few exceptions:

1. Sources like GMA and Parks 'n' Peaks provide spots for multiple different programmes (SIGs).
2. Cluster spots may name SIGs in their comment, in which case the source remains the Cluster, but a SIG is assigned.
3. Some SIGs, such as Worked all Britain (WAB), don't have their own spotting site and can only be identified through comments on spots retrieved from other sources.
4. SIGs have well-defined names, whereas the server owner may name the sources as they see fit.

Spothole's web interface exists not just for the end user, but also as a reference implementation for the API, so I have chosen to demonstrate both methods of filtering.

How is this better than DXheat, DXsummit, POTA's own website, etc?

It's probably not? But it's nice to have choice.

I think it's got three key advantages over those sites:

1. It provides a public, well-documented API with an OpenAPI specification. Other sites don't have official APIs or don't bother documenting them publicly, because they want people to use their web page. I like Spothole's web page, but you don't have to use it—if you're a programmer, you can build your own software on Spothole's API. Spothole does the hard work of taking all the various data sources and providing a consistent, well-documented data set. You can then do the fun bit of writing your own application.
2. It grabs data from a lot more sources. I've seen other sites that pull in DX Cluster and POTA spots together, but nothing on the scale of what Spothole supports.
3. Spothole is open source, so anyone can contribute the code to support a new data source or add new features, and share them with the community.

Why does this website ask me if I want to install it?

Spothole is a Progressive Web App, which means you can install it on an Android or iOS device by opening the site in Chrome or Safari respectively, and clicking "Install" on the pop-up panel. It'll only prompt you once, so if you dismiss the prompt and change your mind, you'll find an Install / Add to Home Screen option on your browser's menu.

Installing Spothole on your phone is completely optional, the website works exactly the same way as the "app" does.

Why hasn't my spot/alert shown up yet?

To avoid putting too much load on the various servers that Spothole connects to, the Spothole server only polls them once every two minutes for spots, and once every hour for alerts. (Some sources, such as DX clusters, RBN, APRS-IS and WWBOTA use a non-polling mechanism, and their updates will therefore arrive more quickly.) Then if you are using the web interface, that has its own rate at which it reloads the data from Spothole, which is once a minute for spots or 30 minutes for alerts. So you could be waiting around three minutes to see a newly added spot, or 90 minutes to see a newly added alert.

What licence does Spothole use?

Spothole's source code is licenced under the Public Domain. You can write a Spothole client, run your own server, modify it however you like, you can claim you wrote it and charge people £1000 for a copy, I don't really mind. (Please don't do the last one. But if you're using my code for something cool, it would be nice to hear from you!)

Data Accuracy

Please note that the data coming out of Spothole is only as good as the data going in. People mis-hear and make typos when spotting callsigns all the time. There are also plenty of cases where Spothole's data, particularly location data, may be inaccurate. For example, there are POTA parks that span multiple US states, countries that span multiple CQ zones, portable operators with no requirement to sign /P, etc. If you are doing something where accuracy is important, such as contesting, you should not rely on Spothole's data to fill in any gaps in your log.

Privacy

Spothole collects no data about you, and there is no way to enter personally identifying information into the site apart from by spotting and alerting through Spothole or the various services it connects to. All spots and alerts are "timed out" and deleted from the system after a set interval, which by default is one hour for spots and one week for alerts.

Settings you select from Spothole's menus are sent to the server, in order to provide the data with the requested filters. They are also stored in your browser's local storage, so that your preferences are remembered between sessions.

There are no trackers, no ads, and no cookies.

Spothole is open source, so you can audit the code if you like.

Thanks

This project would not have been possible without those volunteers who have taken it upon themselves to run DX clusters, xOTA programmes, DXpedition lists, callsign lookup databases, and other online tools on which Spothole's data is based.

Spothole is also dependent on a number of Python libraries, in particular pyhamtools, and many JavaScript libraries, as well as the Font Awesome icon set and flag icons from the Noto Color Emoji set.

This software is dedicated to the memory of Tom G1PJB, SK, a friend and colleague who sadly passed away around the time I started writing it in Autumn 2025. I was looking forward to showing it to you when it was done.