Compared
Four services, and the cells nobody has checked.
Comparison pages are usually written by the winner. This one has a rule instead: a cell only gets an answer if a dated review of that service says so. Everything else reads “not verified”, including cells where we are fairly sure of the answer. 15 cells say that today, and they are the honest state of what we know.
| What is being compared | CAS | OpenFate.ai | XuanSeal | Co-Star |
|---|---|---|---|---|
| Computation engine disclosed | Yes. The bridge, the counting rule and the element we could not bridge are written out on The Four Skies. | Not verified. | Not verified. | Markets its positions as coming from NASA data. Nothing beyond that marketing is verified. |
| Every claim cites a placement | Yes. Each paragraph of the sample reading names the pillar, palace or planet it came from. | Not verified. | Not verified. | Not verified. |
| Verdict decided by code, not the model | Yes. Agreement is counted in code from the five-element cycle. The model writes up a verdict it did not reach. | Not verified. It sells a reading across two or three systems. Whether anything decides between them is the open question. | Not verified. | Not verified. |
| One-time payment | One payment of $9.90 when pricing starts. Nothing costs anything while our payment provider is in review. | Not verified. | Yes for the reports — $39.99 for the ten-chapter BaZi book, $29.99 for the 2026 year book. There is also a $99 a year plan. | No. Free tier and a subscription. |
| Works without a birth time | Yes, with two of the four skies shut and the reading saying so rather than guessing at them. | Not verified. | Not verified. | Not verified. |
| Eastern and Western in one reading | Four systems: BaZi, Zi Wei Dou Shu, the Western chart and the Thai day. | Yes. A combined reading across Western, BaZi, Zi Wei Dou Shu and Vedic. | No. BaZi only, with no Western astrology. | No. Western astrology only. |
| Chapters and length | Nine chapters, about 5,700 words. | Not verified. | Ten chapters. The word count is not verified, so we cannot claim ours is longer. | Not verified. |
| App | No. Web only. | Not verified. | No. Web only. | Yes, and it is where the product lives. |
Where we lose
- Scale
Co-Star reported more than 30 million users in 2023. We have not launched. Nothing in this table changes that gap, and a comparison that left it out would be the kind of page we are trying not to write.
- Length
XuanSeal's natal book is ten chapters to our nine. We have not bought one, so we do not know how many words that is, and we are not going to imply ours is bigger.
- No app
Co-Star is an app and we are a website. If what you want is a widget on your home screen, we do not have one and are not building one.
- Not the only crossing
OpenFate.ai sells a reading across Western, BaZi, Zi Wei Dou Shu and Vedic. Crossing East and West is not ours alone. What we have not been able to check is whether anything there decides between the systems or whether they are set side by side.
How this table was made
The competitor cells come from one internal review dated 2 September 2026, in which each site was opened and read, plus an earlier reference file. Prices were on the page on that day. XuanSeal launched in June 2026, so its prices are young and we expect to redo this table every quarter.
“Not verified” means exactly that: nobody here has bought the product or confirmed the answer, so the cell stays empty rather than getting a guess. Two of those purchases are planned. When they happen, the cells change and this note stays.
If you work at one of these services and a cell is wrong, we would rather fix it than keep it.
The rows we can prove are the ones about method.
That is where the difference is meant to be. The bridge between four elements and five, the counting rule that decides which skies agree, and the fact that a model never gets to pick the verdict — all three are written down and none of them are a claim about how accurate we are.
Read the method