Upstage profile, products and governance

The language models are the Solar family. Solar Pro 4 is the closed commercial flagship, announced on 20 August 2026 and built for tool calling and long-document reasoning, and Solar Mini 4 is a compact agent model with 3 billion active parameters. Solar Open 2 is a separate open-weight model on Hugging Face with 250 billion parameters, 15 billion active per token and a 1 million token context window, released in July 2026 under the Upstage Solar License, with Korea Times coverage dated 23 July. Syn Pro, co-developed with Karakuri, was certified as a domestic foundation model by Japan's METI in November 2025. Around the models sit Document Parse and Information Extract, APIs that turn contracts, forms and invoices into structured data, and Upstage Studio, a workflow product for document-heavy teams.

The last six months were busy. Upstage closed the first tranche of a Series C on 15 April 2026 and completed its acquisition of AXZ, the operator of the Daum portal, on 7 May 2026 through a share swap with Kakao. In March 2026 it announced an expanded collaboration with AMD on sovereign AI infrastructure in Korea. Solar Open 2 followed in July and Solar Pro 4 in August, and on 6 October 2026 Upstage launched the next version of Studio, which it says links contracts, invoices and delivery records and processes more than 3 million pages a day for over 100 enterprises. Its API pricing page lists Solar Pro 2 and Solar Pro 3 as reaching end of service on 30 October 2026 (KST).

On funding, Wowtale reported on 15 April 2026 that Sazze Partners led the Series C first close, sized at about KRW 180 billion or $126 million at press-time rates, taking the valuation past $1 billion and total funding to about KRW 400 billion, roughly $280 million. Earlier rounds were a KRW 31.6 billion Series A in 2021, a Series B that Upstage announced as $72 million in April 2024 and a $45 million Series B bridge in August 2025, in which Amazon and AMD took part. The about page names SoftBank Ventures Asia, SK Networks, Korea Telecom and Company K Partners among its investors. Kakao received a stake in Upstage in the AXZ swap; Digital Today says the industry puts it at 15 to 25 percent.

Revenue comes from per-token use of the Solar API, from Document Intelligence and Studio contracts, and from deployment through the AWS, Azure and Snowflake marketplaces or on premises. Digital Today reported on 15 May 2026 that Upstage's revenue was KRW 24.8 billion in 2025, up from KRW 5.9 billion in 2022, and that AXZ's own annual revenue is in the KRW 300 billion range, so consolidated revenue will jump once the deal is booked. Wowtale's April 2026 report adds that revenue growth exceeded 130 percent year over year.

Sung Kim is the CEO. Lucy Park is Chief Product Officer and Kasey Roh is US CEO, both named in the 6 October 2026 Studio release. The about page says the team has more than 100 people and counts more than 100 academic papers; it was named lead organisation for the Korean government's Independent Foundation Model project, per Wowtale. None of the pages read for this profile mention a responsible scaling policy or named red-team partners, and the model documentation is a Hugging Face card with architecture, benchmark and hardware tables rather than a system card.

Upstage loses where a buyer needs guarantees it has not yet published. The Korea region endpoint, which keeps requests and data inside Korea, is a closed beta that needs separate access authorisation and supports five models, with enhanced mode unavailable there. On 11 November 2026 an unauthenticated POST to both api.upstage.ai and kr.api.upstage.ai returned the same HTTP 401 invalid-key error, so the Korea endpoint resolves and answers like the global one but cannot be tried without credentials. Its privacy policy lets the free tier use request and response data for service improvement and research, and the site shows compliance badges but no public trust center. On raw model strength it is measured by its own release against Nvidia's Nemotron 3 Ultra and models from Mistral AI and Cohere, not against the largest US labs; for Korean consumer search and a competing sovereign model, Naver and LG AI Research are the other national names, and on document parsing Reducto is a direct alternative.

Upstage plans a Korea Exchange listing. Digital Today reported in May 2026 that it was accelerating IPO plans for the second half of the year, while the Korea Herald reported on 13 July 2026 that a listing is more likely in 2027, and none of the coverage read for this page confirms a filing. Daum will run as a separate corporation, with Upstage supplying models to it, and the plan is to add Solar to Daum's search. Kakao, which sold Daum, is profiled at Kakao, and its cloud partner is Amazon.