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KOREA'S FIRST AI UNICORNFOUNDED 2020SOLAR SERIESOPENAI-COMPATIBLE APIDOCUMENT AI

Upstage Solar API Pricing (November 2026)

Upstage Solar API prices run from $0.10 to $1.20 per million tokens across 2 current models. The cheapest is Solar Mini 4 at $0.10 input and $0.40 output per million tokens. The flagship, Solar Pro 4, costs $0.30 input and $1.20 output per million tokens. Every rate below was read on Upstage's own pricing page, on the date shown in its row.

Models priced here
2
2 GA
Founded
2020
Yongin, South Korea
Flagship list
$0.30/M
Solar Pro 4 input
Flagship discount
-50%
no end date; was -70% to Oct 10
Valuation
>$679M
Series C-1, 2026
Cached input
-80%
Solar Pro 4 cache hit
§ 01 / PRICES

Upstage Solar API pricing per 1M tokens

Methodology →
Model Input /M Cache read /M Output /M Batch in /M Batch out /M Context Status Checked
Solar Pro 4 solar-pro4 $0.30 $0.06−80% $1.20 — — 512K Flagship 2026-10-23
Solar Mini 4 solar-mini4 $0.10 $0.01−90% $0.40 — — 512K Current 2026-10-23

US dollars per million tokens, list rates on Upstage's own API. Cache read is the price of a cached input token. Batch is the asynchronous API, where the vendor offers one. The date in each row is when we last read it on the vendor's pricing page; it links to that page.

§ 02 / MONTHLY COST

Upstage Solar API monthly cost estimates

What light use (10M input + 2M output tokens a month), medium use (100M input + 20M output tokens a month), heavy use (1B input + 200M output tokens a month) costs on each current model, at list price with no caching and no batch discount.

Model Input / output per 1M Light · 10M + 2MMedium · 100M + 20MHeavy · 1B + 200M
Solar Mini 4 $0.10 / $0.40 $1.80$18.00$180
Solar Pro 4 $0.30 / $1.20 $5.40$54.00$540

Prompt caching and the Batch API cut these figures; the next sections show by how much. For your own token counts, use the LLM API cost calculator.

§ 03 / PRICE HISTORY

Upstage Solar API price history

How Upstage priced 4 models · AUG 26 → SEP 26.

oldest → newest →
$2$1.5$1$0.5 $0.6 $0.15 $0.6 $0.15 $1.2 $0.3 $0.4 $0.1 Solar Pro 2 AUG 26 Solar Pro 3 AUG 26 Solar Pro 4 AUG 26 Solar Mini 4 SEP 26
Input · newest $0.1/M
Output · newest $0.4/M
Each point is a model at its listed $/M price.

Upstage Solar API price changes and releases

Company milestones and the Solar line. Sourced from Upstage's own newsroom, its pricing and docs pages, and Wikipedia.

OCT 30 · 2026
Solar Pro 3, Pro 2 and the original Solar Mini retired - end of service reached; Upstage's model history lists their last builds as deprecated on October 30, 2026 and points them to Solar Pro 4 and Solar Mini 4
LIFECYCLE
OCT 11 · 2026
Solar Pro 4 does not return to list - the 70% window closes and a third phase opens at 50% off until further notice, $0.15/$0.60, on the day Upstage's card had promised list price
PRICING
OCT 10 · 2026
Solar Pro 3 and Pro 2 set to retire - Upstage marks both for end of service on October 30, 2026 (KST) and points them to Solar Pro 4; the notice was not on the pricing page on September 26
LIFECYCLE
SEP 22 · 2026
Solar Mini 4 ships - a 35B mixture-of-experts with 3B active and a 512K window at $0.10/$0.40 list, a third of Solar Pro 4, and 50% off to Oct 22
RELEASE
SEP 09 · 2026
The Solar Pro 4 discount is extended, not ended — a second phase at 70% off runs Sept 11 to Oct 10 at $0.09/$0.36, where the page had promised list price from Sept 11
PRICING
AUG 16 · 2026
AI//COST adds Upstage — Solar Pro 4, Pro 3 and Pro 2 priced from Upstage's own rate card, with the flagship's 90% launch discount recorded against its list price
PRICING
AUG · 2026
Solar Pro 4 ships as an agentic model for tool calling and terminal work, reasoning on by default, launched free for five days and then at 90% off
RELEASE
JUL · 2026
Solar Open 2 announced — an open-weight agent model, with an Upstage AI agent embedded in the Daum portal
RELEASE
2026
Korea's first generative-AI unicorn — Series C-1 of ₩180B (~$122.3M) led by Sequoia Capital, with Hyundai Motor and Kia joining, pushing valuation past ₩1 trillion
CORPORATE
2024
$72M Series B raised to expand globally — at the time the most-funded South Korean AI software company
CORPORATE
DEC · 2023
Solar 10.7B tops the Hugging Face Open LLM Leaderboard, built with Upstage's Depth-Up Scaling technique
RELEASE
OCT · 2020
Upstage founded in Yongin by Sung Kim, previously an HKUST professor and head of Naver's Clova team
CORPORATE
§ 04 / RETIRED

Retired Upstage Solar models and their replacements

2 Upstage Solar models no longer answer on Upstage's API. The price is the last one Upstage listed; the replacement is the current end of the vendor's own succession chain.

Model Status Last price in / out per 1M Use instead
Solar Pro 3 Retired Oct 30, 2026 $0.15 / $0.60 Solar Pro 4
Solar Pro 2 Retired Oct 30, 2026 $0.15 / $0.60 Solar Pro 4
§ 05 / WHICH MODEL

Which Upstage Solar model should you use?

Full price table →
If you want the agentic flagship while it is still discounted…
Solar Pro 4
Profile →
If you need high-volume agents at the lowest Solar rate…
Solar Mini 4
Profile →
If you were on Solar Pro 3 or Pro 2 (both retired Oct 30, 2026)…
Solar Pro 4
Profile →
If you need document parsing and OCR rather than chat…
Document AI, priced separately
Upstage pricing →
§ 06 / WHERE TO BUY

Where to buy Upstage Solar API access

Methodology →
§ 07 / ALTERNATIVES

Upstage Solar API pricing vs other providers

All providers →
PRICE PEER

Zhipu (Z.ai / GLM)

Similar price band with a far broader lineup, free tiers and open weights. But it is China-based and on the US Entity List, which is a procurement question Upstage does not raise.

$0.60/M GLM-4.7 →
CHEAPEST PEER

DeepSeek

Cheaper still off-peak and MIT open weights, but it moved to peak/off-peak billing in August 2026, so its cost now depends on the hour. Upstage's rate is flat.

Peak / off-peak →
FRONTIER LEADER

Anthropic

Leads coding and reasoning by a wide margin, with mature enterprise terms. But an order of magnitude more expensive per token.

Claude lineup →
OPEN-WEIGHT PEER

Mistral

EU-native open weights with GDPR-first residency — the closest analogue to Upstage's compact-model pitch outside Asia, with a wider catalogue.

EU residency →
OPEN-WEIGHT GIANT

Alibaba (Qwen)

The Qwen (Tongyi Qianwen) model family from Alibaba Cloud's Tongyi Lab. First released in 2023, Qwen is the most-downloaded open-weight model family in the world — most tiers ship under Apache 2.0 on Hugging Face and ModelScope, while the proprietary Max tier is served through Alibaba Cloud's Model Studio.

18 models · from $0.03/M →
OPENAI API

OpenAI

The lab behind ChatGPT and the GPT family. Founded as a nonprofit in 2015 by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman and others; restructured into a capped-profit LLC in 2019 and finally into a public-benefit corporation on October 28, 2025. Ships the largest commercial model lineup, the largest consumer AI product, and — after the April 2026 funding round — the highest-valued private AI company in history at ~$852B.

16 models · from $0.02/M →

Upstage Solar API pricing FAQ

Practical questions about Solar pricing, the discount schedule, and what Upstage does not publish.

Q · 01

Which Solar model should I start with?

+
Solar Pro 4 for agentic work - it is the flagship, at a list price of $0.30/$1.20, billed since October 11, 2026 at 50% off ($0.15/$0.60) until further notice, after launch discounts of 90% and 70%. For high-volume calls use Solar Mini 4: a third of Pro 4's list at $0.10/$0.40 with the same 512K window; its launch discount ended on October 22, so that list price is what it bills now. Do not start on Solar Pro 3 or Solar Pro 2: Upstage ended service for both on October 30, 2026.
Q · 02

Why did the flagship cost less than the mid tier?

+
It did, during its launch discount. Solar Pro 4 billed $0.03/$0.12 at 90% off through September 10 and $0.09/$0.36 at 70% off through October 10, 2026 - both under Solar Pro 3's $0.15/$0.60. Upstage moved the end of that 70% window twice (October 10, then October 9, then October 10 again), and when it closed, list price did not follow: since October 11 Solar Pro 4 bills $0.15/$0.60 at 50% off until further notice — the same as Solar Pro 3 — and on October 30 Solar Pro 3 itself left service.
Q · 03

What context window do the Solar models have?

+
Upstage's model history page now gives them: 512K for Solar Pro 4 and Solar Mini 4, 128K for Solar Pro 3 and 64K (65,536 tokens) for Solar Pro 2, with 128K max output on the two newest. When we added Upstage on August 16, 2026 we found no context figure on any first-party page; the docs page we checked then no longer exists, so we cannot say whether the figures were published at the time.
Q · 04

How hard is it to migrate to Upstage?

+
Mechanically, easy. The API is OpenAI-compatible: point the OpenAI SDK at https://api.upstage.ai/v1 and pass a Solar model name. Rate limits scale with your commitment tier - from 100 requests/min and 250,000 tokens/min on Tier 0 to 8,000 and 3M on Enterprise - so size the prepaid tier to your peak load. Accounts on Upstage's legacy tiers are held at 100 requests and 50,000 tokens per minute on the newest models.
Q · 05

Are reasoning tokens billed extra?

+
They are billed, at the output rate. Solar Pro 4 reasons by default, and Upstage's docs count reasoning tokens inside usage.completion_tokens — the same bucket as the visible answer. The response exposes usage.completion_tokens_details.reasoning_tokens so you can see how much of a bill is thinking.
Q · 06

Is Upstage only an LLM company?

+
No — document AI is arguably its core business. Parsing, OCR and information extraction are sold on the same pricing page under a separate tab, with their own units, and are not covered by the per-token rates here. The Embed model, meanwhile, is scheduled for end of service on December 31, 2026, so do not build new retrieval on it.
§ 08 / ABOUT

About Upstage

www.upstage.ai →

Upstage is a South Korean AI company founded in October 2020 by Sung Kim, a former professor at the Hong Kong University of Science and Technology who previously led Naver's Clova team. It is headquartered in Yongin, south of Seoul.

The company made its name twice over. First with document AI — parsing, OCR and extraction — which remains a large part of the business and is priced separately from the chat models. Then with Solar: in December 2023 Solar 10.7B topped the Hugging Face Open LLM Leaderboard, built using Upstage's own Depth-Up Scaling (DUS) technique, which grows a model by duplicating and re-stacking layers rather than training a larger one from scratch. The result was a compact model punching well above its parameter count — which is still the line's pitch.

Funding has escalated quickly: a $72M Series B in 2024 made it the most-funded South Korean AI software company at the time, and a ₩180 billion (~$122.3M) Series C-1 led by Sequoia Capital — with Hyundai Motor and Kia participating — pushed its valuation past ₩1 trillion and made it Korea's first generative-AI unicorn.

For buyers, the practical picture is this. The API is OpenAI-compatible, so trying it costs a base-URL change. Prices are low against Western frontier labs and roughly in the range of the cheaper Chinese labs, without the procurement questions a China-based vendor raises for some teams. Specs are now published on its model history page - a 512K window on Solar Pro 4 and the new Solar Mini 4 - and rate limits scale with a prepaid commitment tier, from 100 requests/min on Tier 0 to 8,000 on Enterprise. Size the tier before sizing the model: at the default tier the rate limit binds long before the price does.