Co-Star
Acquired8 known investors
Co–Star is a New York astrology and social networking app that generates NASA-data-based natal charts and daily horoscopes.
Also known as Co-Star Astrology Society · Co–Star · Co–Star Personalized Astrology
Founders & leadership
Investors · 8
Also in the syndicate · 2
Company profile
researched Aug 2026Co–Star is an American astrology and social networking service, operated by Co–Star Astrology Society and headquartered in New York City. Users enter their date, time and place of birth to generate an astrological natal chart and receive daily horoscopes and push notifications; they can add friends to compare charts and view compatibility readings.
The service combines publicly accessible NASA JPL data on planetary positions with human-written interpretive text. Co–Star's algorithm maps human-written text snippets to planetary movements to assemble personalized content, and the company describes the horoscopes as produced by human astrologers collaborating with AI technology. In July 2023 it added The Void, an in-app service for asking open-ended questions answered from Co–Star's astrological database.
The app is distributed free on iOS and Android with in-app purchases for premium features such as full natal charts of non-users, love reports, and Eros for couples. In July 2026, TechCrunch reported, citing Bloomberg, that AI lab Midjourney had acquired Co-Star for undisclosed terms, with Co-Star's roughly two dozen employees joining Midjourney.
Founding story
Banu Guler created an astrological chart as a gift in 2015; the idea subsequently developed into a mobile app built with collaborators Anna Kopp and Ben Weitzman, launching publicly in 2017.
Business model
Co–Star distributes a free consumer mobile app on iOS and Android and monetizes through in-app purchases and premium features. Paid features listed by the app stores include asking questions of "the stars" (The Void), viewing the full natal chart of someone who does not use the app, a personalized report on how a user loves, and Eros, a couples-oriented compatibility feature. Some user reviews state that features previously available for free have moved behind payment.
In-app purchases and premium/subscription features within an otherwise free app.
Traction
More than 20 million downloads reported as of April 2021; 5M+ downloads on Google Play; about 4.3 million monthly active users reported in July 2026. Ratings of 4.8 across 206K iOS ratings and 4.6 across roughly 96K Google Play reviews, plus App Store Editors' Choice recognition.
Latest developments
On July 24, 2026, TechCrunch reported, citing Bloomberg, that Midjourney had acquired Co-Star for undisclosed terms; Co-Star's team of about two dozen employees joined Midjourney, and Co-Star was reported to have roughly 4.3 million monthly active users. The Google Play listing shows the app still being updated as of June 2026.
▸Full profile — market position, technology, go-to-market, geography, history, risks & controversies
Market position
One of the more widely covered consumer astrology apps, with more than 20 million downloads reported at the time of its April 2021 Series A and about 4.3 million monthly active users reported at acquisition in 2026. It ranked #50 in the App Store's Lifestyle chart at the time of the listing and holds a 4.8 rating from 206K iOS ratings and 4.6 from 96K Google Play reviews.
Coverage cited in the sources emphasizes the app's distinctive editorial voice — described variously as "slightly robotic," "brutally honest," "truly insane" and comparable to "a free therapy session" — alongside its use of NASA JPL data and a hybrid human-writer plus algorithmic/AI content pipeline, and its social layer for comparing charts with friends.
Technology
The service uses artificial intelligence to analyze publicly accessible NASA JPL data and identify patterns in a user's transits, charting planetary positions in real time. An algorithm maps human-written text snippets to planetary movements to generate personalized daily horoscopes, compatibility readings and birth-chart interpretations; the company states human astrologers collaborate with AI to produce this content. The Void applies the same astrological database to open-ended user questions.
Go-to-market
Direct-to-consumer distribution through the Apple App Store and Google Play, amplified by press coverage (New York Times, Vogue, Vanity Fair, Rolling Stone Australia, The Verge, Newsweek, Business Insider, Gizmodo, BuzzFeed News), celebrity mentions, App Store editorial features including Editors' Choice and two App of the Day placements, and social media accounts on Instagram, TikTok and Twitter. The Android launch was seeded via a 120,000-person waitlist.
Consumers interested in astrology, with coverage describing a millennial and young-adult user base and, as of 2021, increased adoption among young women in the United States. The Google Play listing carries a Teen content rating.
Geography
Headquartered in New York City; the developer listing gives an address at 401 Broadway Ste 610, New York, NY 10013, United States. The app is available in English on iOS and Android.
History
The concept began in 2015 when Banu Guler created an astrological chart as a gift; the idea later developed into a mobile application with collaborators Anna Kopp and Ben Weitzman. The app launched publicly on October 17, 2017. The company raised a $750,000 pre-seed round from Female Founders Fund in early 2018, a $5.2 million seed round from Maveron, Aspect and 14W in 2019, and a $15 million Series A led by Spark Capital announced in April 2021. An Android version shipped in January 2020 to a 120,000-person waitlist, and The Void question-answering feature launched in July 2023. In July 2026, Midjourney acquired the company on undisclosed terms.
Risks & controversies
User reviews on Google Play criticize the removal of previously free content behind paywalls and login failures via Facebook authentication; an App Store review calls the in-app purchases expensive. The Google Play data-safety section states no data is shared with third parties, that the app may collect personal info and messages among other data types, that data is encrypted in transit and that deletion can be requested.
Compiled by commissioned research from 4 cited public sources — announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed — not independently audited.
Timeline · 5
launches, deals, and filingsAI lab Midjourney acquired Co-Star, per a Bloomberg report cited by TechCrunch. Deal terms were not disclosed; Co-Star's team of about two dozen employees joined Midjourney.
The iOS app is listed with an Editors' Choice award and is described as a 2x App of the Day; ranked #50 in the Lifestyle chart.
Co–Star released an in-app service called The Void, letting users ask open-ended questions and receive answers informed by Co–Star's astrological database.
Two years after the iOS release, Co–Star launched its Android app to a waitlist of 120,000 people.
Co–Star, an astrological social networking service, was founded and released on October 17, 2017, initially on iOS.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
▸Research sources · 4
primary sources listed
- Co–Star Personalized Astrology - App Store - Appleapps.apple.com · web
4 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does Co-Star do?
- Co–Star is a New York astrology and social networking app that generates NASA-data-based natal charts and daily horoscopes.
- Who founded Co-Star?
- Co-Star was founded by Banu Guler.
- Who are Co-Star's investors?
- Co-Star's investors include Imagination Capital, Maveron, Acrew Capital, Female Founders, Gingerbread Capital, Spark Capital.