Planetarium vs Simile

What is Simile?

A foundation model of human behavior that simulates how customers, employees or populations respond to change. It is built for enterprises in consumer, finance, travel, media, health and telecoms.

Populations that start from real people, trained on daily studies, purchase data and AI-led voice interviews; a second model labels each result's confidence.

How do Planetarium and Simile compare?

Row by row, from each company’s own pages. Where one publishes nothing on a point, the row says so.

How accurate is Simile?

Matched people's answers 85% as well as people matched their own when asked again. The figure comes from an academic paper by its founders: a 2024 Stanford study of 1,000 people; the company also reports over 7,000 evaluations and a per-result confidence label.

Planetarium was right 87 times in 100 when it names a winner (575 of 660), on 1,500 published news-headline A/B tests (Upworthy, 2013 to 2015), held out and scored once (October 2026). It named a winner on 660 and called the other 840 too close. Headlines only. The full record is on the accuracy page.

When is Simile the better choice?

• You need a simulation of individuals, and a confidence label on each result.
• You are rehearsing an earnings call, a policy change or a litigation outcome.
• You want a custom model trained on your own data.

When should you choose Planetarium?

• You want to test creative, messages, surveys or a website yourself, today.
• You want a published price and your first test free.
• You want an API or MCP for your own tools (Growth plan, $999 a month).

How much does Simile cost?

No price on the site.

Planetarium is self-serve by card: Starter $99, Pro $399, Growth $999 a month. First test free. See pricing.

How was this page made?

We publish this page and sell in this category. Every claim about another company comes from that company’s own public pages, or a paper or partner report it cites, read on October 27, 2026, and each is listed below. Where a company publishes nothing on a point, the page says so; that does not mean it cannot do it.

Each company measures accuracy its own way, on its own tests, so the figures are shown side by side but never ranked as one league table. We did not trial the other products. Our own figures are the ones on our pricing and accuracy pages. Something out of date? Tell us through the contact page and we will correct it.