About Boardhang

Boardhang is made by two climbers with a MoonBoard and a DIY LED system behind it. It is free, open source, and not affiliated with Moon Climbing.

Why it exists

Our board runs the open-source ArduinoMoonBoardLED firmware, and we drove it with the official app for a while. The friction added up. The default sorting never made sense and nothing was saved, so every trip into the catalog started with setting the same filters again. The grade pyramid didn’t add up. Climbing together meant constantly cross-checking who had done what. And every time someone changed the problem, someone else asked which one was lit.

So we wrote the app we wished we had — first for our own board, then for anyone with the same setup and the same complaints.

We are not Moon Climbing

Boardhang is unofficial. It is not affiliated with, or endorsed by, Moon Climbing Ltd, and MoonBoard is their trademark. The official MoonBoard app remains the only sanctioned, complete source of problems, and for some things — a complete problem list and an official logbook — it is still the right tool.

Where the catalog comes from

The catalog is a curated subset, not every problem ever set: around 12,000 problems including 2,832 official benchmarks, across MoonBoard 2016, MoonBoard 2024, Masters 2017, Masters 2019 and Mini MoonBoard 2025. The data is mirrored from the community Boardsesh API, which is the foundation a lot of community MoonBoard tools build on, including ours. It is not an official Moon Climbing dataset.

Built in the open

The whole app — catalog to Bluetooth — is on GitHub under the MIT license. Read the code, check our claims, or build on it. If something bugs you or there’s a feature you wish existed, open an issue or send a pull request.

Get in touch

For bugs, feature ideas and corrections, the fastest route is to open an issue — it is public, so other people benefit from the answer. For anything you would rather not raise in public, email [email protected]. That includes rights enquiries: if you hold rights in anything published here and want it changed or taken down, write to us and we will act on it.

What it costs

Nothing. Browsing the catalog and lighting problems on your board need no install and no account. Collaboration sessions need a free sign-in, because they show your crew what everyone has sent. There is no advertising and nothing is sold — see our privacy notice.