AstroSeek is one of the most loved websites in Western astrology — generous free calculators, dependable chart drawings, and a passionate community of users. The honest part is this: AstroSeek's strength has always been its consumer-facing web UI, not a polished developer API. If you came here looking for an API alternative because the AstroSeek developer surface is too limited for production work, this article is for you.
We'll compare five alternatives across pricing, Western coverage depth, transit features, latency, and developer experience.
Verified: May 10, 2026. Pricing changes frequently. Confirm current rates on each vendor's site before committing.
Why look for an alternative?
AstroSeek's main offering is the website, not the API. The API surface is small, the documentation is sparse compared to commercial-first providers, and latency is roughly ~750ms in our benchmark testing — fine for occasional batch jobs, too slow for interactive consumer apps.
Teams typically search for AstroSeek alternatives for four reasons:
None of this diminishes what AstroSeek built for the astrology community. It's a recognition that "great consumer site" and "great developer API" are different products. The alternatives below are positioned for the second job.
Quick comparison
| Provider | Pricing Model | Free Tier | Endpoints | Transits | Western House Systems | AI Interpretations | Avg Response |
|---|---|---|---|---|---|---|---|
| Astrology-API.io | Flat per-request | 50 req/mo | 100+ | Deep (current, future, exact aspects, ingresses) | 23 | Yes (multilingual) | ~287ms |
| Astrologer (Kerykeion) | Tiered on RapidAPI | Free tier on RapidAPI | ~12 | Core | ~9 | No (BYO LLM) | ~400–900ms |
| DivineAPI | Per-product subscription | 300 req/mo with paid plan | ~20 | Basic | 12 | No | ~450ms |
| RoxyAPI | Per-subscription | Trial available | ~30 | Moderate | 8 | Limited | ~50ms raw (fast) |
| Swiss Ephemeris (self-hosted) | One-time license | AGPL free | Library | Build yourself | All | Build yourself | Depends on your server |
1. Astrology API
The closest like-for-like alternative to AstroSeek for Western-focused developers who want production-grade infrastructure plus the deep technique coverage AstroSeek's web UI is famous for. 100+ endpoints, ~287ms average response, 23 house systems, AI interpretations in 9+ languages.
- Free: $0/mo — 50 requests, no credit card
- Starter: $11/mo — 1,000 requests
- Professional: $37/mo — 55,000 requests
- Business: $99/mo — 220,000 requests, all endpoints
- Enterprise: $399+/mo — custom
- Computes with Lx Ephemeris, our own Rust engine on NASA JPL DE440, verified against JPL Horizons to under 0.003″
- 23 house systems including Placidus, Koch, Regiomontanus, Campanus, Equal, Whole-Sign, Porphyry, Morinus, Topocentric, Alcabitius, and rarer systems professional Western astrologers ask for
- 97+ Arabic parts (vs. the handful most APIs expose)
- Full transit suite: current transits, future transits with exact aspect dates, planetary ingresses, retrograde watch with station details, void-of-course Moon
- Secondary progressions, solar arc directions, primary directions, profections, zodiacal releasing
- Solar and lunar returns
- Composite (midpoint) and Davison relationship charts
- Harmonic charts (any harmonic n)
- Fixed-star conjunctions (Sirius, Regulus, Spica, Algol, 8+ stars)
- AI interpretation endpoints in 9+ languages, deterministic per seed
- Free tier is intentionally small at 50 req/mo to push real-traffic users into Starter
- No SVG chart rendering in responses (returns JSON; you render with a client-side library)
- Slightly less Vedic depth than Vedic-specialist APIs — though it covers the major Vedic techniques
2. Astrologer API (Kerykeion)
The hosted version of the open-source Kerykeion Python library. Active, well-documented, Western-strong, with SVG chart rendering included in responses. Distributed via RapidAPI.
- Mature underlying ephemeris library via Kerykeion — solid accuracy for standard chart work
- SVG chart rendering in responses — saves you a client-side chart-drawing library
- Clean REST API: natal, synastry, transit, composite, solar return, lunar return
- Open-source roots (Kerykeion is AGPL-3.0); contribute back if your project is OSS
- Active maintainer (g-battaglia); the underlying library evolves consistently
- ~12 endpoints vs. 100+ on Astrology API — narrower coverage
- ~9 house systems (Placidus default + 8 others) vs. 23 on Astrology API
- RapidAPI marketplace layer adds latency (~400–900ms typical from US East)
- No native AI interpretations; you bring your own LLM
- English primary; locale support depends on library configuration
- Pricing is set at the RapidAPI tier level, which is request-based but routes through RapidAPI's billing
3. DivineAPI
A commercial multi-modality API: astrology, tarot, and numerology under one vendor. Decent Western coverage with 12 house systems, good documentation, responsive support.
- Multi-modality: astrology + tarot + numerology in one vendor
- 12 house systems — more than the typical 4-to-8 you find elsewhere
- Documentation quality is above average; sub-48-hour support responses in our testing
- Stable and reliable for moderate load
- ~20 endpoints; doesn't reach the depth of Astrology API or what AstroSeek's web UI shows
- No native AI interpretations
- ~450ms average response — fine, not at the top of the pack
- Per-product pricing stacks if you want all three modalities
- Western coverage is solid; advanced techniques (primary directions, zodiacal releasing) are absent
4. RoxyAPI
A newer all-in-one astrology API with strong raw response speed and MCP (Model Context Protocol) integration for AI/LLM workflows. Good Western fundamentals.
- Sub-50ms raw response on basic endpoints — among the fastest we've measured
- MCP support for AI agent integrations is genuinely novel
- 30+ endpoints across natal, transit, synastry
- Clean, well-organized documentation
- Newer than Prokerala and other long-established APIs; smaller customer base
- ~8 house systems vs. 23 on Astrology API
- AI interpretation features are limited; not multilingual at the depth Astrology API offers
- Horoscope text generation is English-primary (see our horoscope API comparison)
- Endpoint count narrower than Astrology API at the deeper end (no zodiacal releasing, primary directions, profections)
5. Swiss Ephemeris (self-hosted)
The originator library. Its Swiss publisher, which also runs astro.com, sells a commercial license that lets you host the calculation engine yourself. This is the path most desktop astrology software vendors take.
- You own the calculation infrastructure — no per-request cost
- All house systems, all ayanamsas, all asteroids, fixed stars — the full library surface
- Long-established accuracy track record; many desktop tools and some APIs run on it
- One-time license amortizes to nearly zero over a multi-year product
- Works fully offline; ideal for desktop and on-premise software
- You operate the infrastructure: ephemeris data files (gigabytes), C/Python/Java integration, your own REST layer if you want one, your own caching, your own monitoring
- AI interpretations, derived techniques (Arabic parts, dashas, etc.) are all on you to build
- Engineering time is the hidden cost; expect 4–12 engineer-weeks to reach feature parity with a managed API
- AGPL-free path requires open-sourcing your full app; commercial use needs the paid license
Decision framework
Pick your path based on your real constraints, not the vendor with the best landing page.
FAQ
Why does AstroSeek not have a strong commercial API?
AstroSeek was built as a consumer destination — free calculators, community discussion, chart drawings. The public API is a side-effect of the consumer infrastructure rather than a deliberately positioned developer product. There's nothing wrong with that strategy; it's just a different focus than commercial-first APIs.
What's the most underrated criterion when picking a Western astrology API?
House system breadth. Professional astrologers are particular about house systems — a Hellenistic practitioner wants Whole-Sign, a traditional Renaissance astrologer wants Regiomontanus, a modern psychological astrologer probably uses Placidus or Koch. Most APIs ship 4–8 systems. Astrology API ships 23. If your audience includes professional astrologers, this matters more than it sounds.
How important are AI interpretations?
For consumer-facing astrology apps in 2026, increasingly important. Generic Sun-sign horoscope text is a known retention killer (1/12 of your users see identical text). AI-generated interpretations based on the full birth chart feel personal, which drives engagement. The question is whether you build the AI layer yourself (BYO LLM + prompts + safety + testing) or use a vendor that ships it (Astrology API). The build cost is real — months of work — and the operational cost of running your own LLM bill is also real.
What about Astrolog or Morinus or other open-source desktop tools?
Those are excellent for personal use and astrologer workflows but they're not APIs you can call from a mobile app. If you want their math, the underlying engine is often the library from section 5 — license that directly from its publisher.
How fast can I switch from AstroSeek's API to one of these?
Days, not weeks, for most teams. AstroSeek's API surface is narrow, so the migration mapping is small. Start with Astrology-API.io's free tier, write a thin adapter layer that normalizes response shapes to your internal models, A/B between providers on one endpoint at a time. Most migrations of this kind take 1–2 engineer-weeks.
Do I need an API at all, or can I self-host an ephemeris library?
Honest answer: most app teams shouldn't self-host. The library is excellent, but the operational work — ephemeris data file management, the REST layer you'll have to build, the caching, the monitoring — typically costs more in engineer-hours than 12–24 months of a managed API subscription. The exceptions are desktop software vendors and teams with very deep math/infra muscle.
