Street View for the Sun
Heliora runs in the web browser. There is no iOS or Android app. Drop a pin anywhere on Earth and see the sun's exact path across the sky from that spot, with the real terrain on the horizon.
The Problem
Every sunrise/sunset app on the internet assumes you're standing on a perfectly flat plane. They all give you the same time whether you're in a deep valley or on an exposed ridge.
If you're a photographer chasing golden hour, an eclipse chaser picking a viewing spot, or just someone who wants to know when the sun actually clears the mountain behind your house — those flat-earth times can be off by 10, 20, even 40 minutes.
Heliora fixes this. It reads real satellite elevation data, builds a 360° terrain profile from your exact coordinates, and computes when the sun actually appears or disappears behind the landscape. No approximations, no lookup tables — real geometry from real terrain.
Key Features
Terrain-Adjusted Sun Times
Sunrise and sunset times computed against a 360° horizon profile built from satellite elevation data. See exactly when the sun clears a ridge or drops behind a mountain at your location.
3D Sky View
A full-dome sky simulation showing the sun's arc, moon position, and real terrain silhouette on the horizon — rendered in your browser with Three.js. Drag to look around, scrub time to watch the sun move.
Eclipse Simulation
Preview any solar eclipse from 2024–2035 at any location. See contact times, obscuration, sky darkening, corona, diamond ring effect, and whether terrain blocks the low sun during the event.
Line-ups Behind a Landmark
Pick a named summit or any target point, and Heliora searches ahead for the moments the sun (next 12 months), the full moon (next 18 months) or a naked-eye planet (next 60 nights) sits behind it. Candidates that the terrain horizon would hide, or that fall in daylight, are dropped.
Golden Hour Finder
Scan upcoming days to find when golden hour lasts longest at your location. Get precise start/end times and compass bearings for planning photo shoots.
Night Sky
Stars, constellations, and Milky Way visibility computed from sidereal time. See when the galactic center rises above your terrain horizon during astronomical darkness.
Works Anywhere
Global coverage. Drop a pin on any coordinate on Earth. Terrain data covers all landmasses. Shareable URLs let you send an exact view to someone else.
What Makes Heliora Different
Published sunrise and sunset tables compute against a flat mathematical horizon, so they give the same time for a valley floor and a nearby hilltop. Some photography apps let you check terrain by hand, one obstacle at a time. Heliora computes the whole horizon for you and uses it everywhere:
For a fuller product-by-product account, including what the paid apps offer that Heliora does not, see the comparison page.
How It Works
Solar Eclipses, 2026 and 2027
Heliora launched around the total solar eclipse of 12 August 2026, which crossed northern Spain with the sun low in the west, so a ridge could take it mid-event. About 27,000 people used Heliora on the day. The next total eclipse, on 2 August 2027, crosses southern Spain, North Africa and Egypt, with more than six minutes of totality near Luxor.
Heliora has eclipse guides for over 33,000 cities for each of the two eclipses, each computed individually with local contact times and obscuration. Use the 3D sky view to check whether a nearby mountain blocks the sun at your chosen viewing spot.
Replay the 2026 eclipse from Oviedo, Spain › · 2026 vs 2027 compared ›
Coverage
9 August 2026 — Il Post wrote about Heliora: Come osservare l’eclissi solare del 12 agosto dall’Italia
11 August 2026 — Internazionale wrote about Heliora: Come vedere l’eclissi solare del 12 agosto
12 August 2026 — Il Post wrote about Heliora: Come vedere l’eclissi solare di stasera
12 August 2026 — t-online covered Heliora: Sonnenfinsternis heute: Tool zeigt Ihnen Blickrichtung und Bedeckung
Heliora was also linked from CERN's eclipse-safety announcement for its Geneva site, Eyes on the sky: a rare solar eclipse will be visible from CERN on 12 August (10 August 2026), as a way to find a viewing spot. That page is a safety notice from CERN's HSE department, not a review or an endorsement of Heliora.
Frequently Asked Questions
- What is Heliora?
- Heliora is a free, browser-based tool that shows the sun's exact path from any location on Earth, with sunrise and sunset times adjusted for real terrain. It uses satellite elevation data to compute when mountains, ridges, or hills actually block the sun at your specific position — not just the flat-horizon time that most apps show.
- Is Heliora free?
- Yes. Heliora is completely free to use. No account, no sign-up, no paywall. Open the app, drop a pin, and get terrain-adjusted sun data immediately.
- How accurate are the sun times?
- Sun and moon positions are computed to within ±1 arcminute using the astronomy-engine library. Terrain data comes from the free AWS Terrain Tiles dataset (Terrarium tiles, built from NASA SRTM, USGS 3DEP and other sources), with elevation sampled at roughly 110 m spacing (from source datasets of ~30 m resolution). The combination gives sunrise/sunset accuracy within about 1–3 minutes for most locations. Full details are on the method & accuracy page.
- How does it handle eclipses?
- Heliora computes local eclipse circumstances for any location using a precision astronomical engine. It calculates contact times (C1 through C4), obscuration percentage, and eclipse type from your exact coordinates. The 3D sky view renders the eclipse in real time — sky darkening, corona, diamond ring effect — and shows whether nearby terrain blocks the low sun during the event.
- What makes it different from TimeAndDate or PhotoPills?
- Published sunrise and sunset tables assume a flat horizon. They give the same time whether you're in a valley or on a ridge. Heliora decodes real elevation data from satellite terrain tiles, ray-casts a 360° horizon profile from your exact coordinates, and uses it automatically for rise and set times and for its landmark line-up scans. It also renders a full 3D sky dome with the actual terrain silhouette. PhotoPills does things Heliora does not; the comparison page lists them.
- Is Heliora the same as the iOS apps named Heliora?
- No. Heliora is the free web app at heliora.app, built in Spain, and it has no native iOS app. Two App Store apps from other developers use the name, "Heliora: Sun Path Tracker" and "Sun Position Heliora". Neither is affiliated with heliora.app. The terrain-horizon features, eclipse simulation and landmark line-up scans described on this page belong to heliora.app.
- Does it work on mobile?
- Yes. Heliora works in any modern mobile browser (Chrome, Safari, Firefox) — no install needed. The interface adapts with a bottom sheet panel and touch-friendly controls.
Free. No account needed. Drop a pin and see terrain-adjusted sun data in seconds.