About Coeluna
Coeluna is a free, account-free astrology studio. We build clear, beautifully made tools — birth charts, daily horoscopes, compatibility and tarot — that run entirely in your browser, so your birth details never leave your device. This page explains who makes Coeluna, how the calculations work, and how we think about astrology.
What Coeluna is
Coeluna turns your date, time and place of birth into a complete natal chart — Sun, Moon, rising sign, every planet and house — and explains each placement in plain language. Alongside the chart we offer daily horoscopes, synastry readings for relationships, a full tarot deck and a growing library of guides. Everything is free, there are no accounts, and there is nothing to install.
Who makes it
Coeluna is made by a small, independent team of astrology writers and software engineers. Our writers draft and edit every interpretation by hand — the sign, planet, house, aspect, placement and compatibility pages are written, not auto-generated — while our engineers build the chart engine and keep the site fast and private. We publish under the Coeluna name rather than individual bylines, but everything you read here is human-written and human-reviewed.
How we calculate your chart
Planetary positions are computed from well-established astronomical models — the same VSOP and Meeus methods used by professional ephemerides — and house cusps from your exact birth time and coordinates. City and time-zone data come from the open GeoNames database. Because all of this runs in your browser, the same birth details always reproduce the same chart, and none of it is sent to a server.
How we write about astrology
We treat astrology as a tool for reflection and self-understanding, not prediction — and never as medical, legal or financial advice. Our interpretations aim to be specific, fair and genuinely useful, describing tendencies and tensions rather than making promises. Take what resonates, leave what doesn't, and always trust your own judgement over a chart.
Private by design
Your birth data is processed locally and is never transmitted to or stored by us. Recent charts live only in your browser's local storage, on your own device. The full details are in our privacy policy.
Get in touch
Questions, corrections or feedback are always welcome — email us at contact@coeluna.com.