SK Telecom A.X
SK Telecom's Korean-first open-weight LLM family, led by A.X K2
Overview
SK Telecom A.X is a family of Korean-focused large language models: A.X K2 (688B MoE, 256K context), K1 (500B), and the smaller 4.0, 4.0 Light and 3.1, with open weights on Hugging Face (mostly Apache 2.0; 4.0 under the Qwen licence). Powers SKT's A. assistant; enterprise access via SKT.
Pricing
Pricing shown for reference only. These figures reflect RECATOOLS research as of 1 Oct 2026 and may be out of date or incomplete. This is not financial or purchasing advice — always confirm the current price on the provider’s official website before making any decision.
- A.X K2, K1, 3.1 and 4.0 Light (Apache 2.0)
- A.X 4.0 (Qwen licence)
- Quantised NVFP4 and GGUF builds
- Lightweight and custom models
- Sovereign AI Package
Use cases
What you can produce with SK Telecom A.X
- A.X K2 688B mixture-of-experts model
- A.X K1, 4.0, 4.0 Light and 3.1 models
- Open weights on Hugging Face
- Vision, audio and speech derivative models
- Powers the A. (A-dot) assistant and A. Biz
ASEAN Perspective
SK Telecom A.X in Southeast Asia
SK Telecom's GTAA partnership with Singapore's Singtel — whose group covers 770 million subscribers across 21 countries including Indonesia, India, and Australia — is the clearest near-term ASEAN on-ramp for A.X technology. SKT is also building an AI data centre in Vietnam (in partnership with SK Innovation, using LNG cold-energy cooling) and has named Malaysia and Singapore as target markets for its Sovereign AI Package. Data-residency is central to SKT's pitch: the Sovereign AI Package explicitly bundles domestic AIDC infrastructure with A.X K1 so that governments and enterprises can run Korean or nationally-localised LLMs without data crossing borders — a compelling argument in ASEAN markets with growing data-protection mandates. However, as of mid-2026 no A.X production service is publicly live in any Southeast Asian country, and the GTAA telco LLM supports Bahasa as a named target language but has not yet publicly benchmarked ASEAN-language performance.
A.X has grown into one of Korea's strongest open-weight model families: A.X K2 is a large, permissively licensed mixture-of-experts model with long context and strong Korean results on SKT's own benchmarks, and SKT remains in the final stage of Korea's sovereign AI programme. All the performance figures are self-reported, there is no public API, and running K2 requires serious hardware. A strong option for Korean-language work and for teams that want large open models; others will find more support around global alternatives.
What we found
A.X is SK Telecom's family of large language models, branded in 2023 and built largely for Korean. Its flagship, A.X K2, released in July 2026, is a mixture-of-experts model with 688 billion parameters, 33 billion of them active, a 256,000-token context, thinking and non-thinking modes, and support for Korean, English, Chinese, Japanese and Spanish; SKT says it averages 32.2 points better than A.X K1 across 14 benchmarks and scores 80.5 on the Korean KMMLU-Pro test, the best in SKT's own comparison. It follows A.X K1, a 500-billion-parameter model announced in December 2025 that SKT calls Korea's first hyperscale AI model, and the smaller A.X 4.0, 4.0 Light and 3.1; A.X 4.0 scored 78.3 on KMMLU against 72.5 for GPT-4o, by SKT's measure. Derivative models cover vision, audio and speech, and SKT says its next model will reach a trillion parameters. All these benchmarks are SKT's own.
A.X powers SKT's A. (A-dot) assistant, which SKT says has 10 million monthly users, including call summaries in A. Phone and A. Note; the A. Biz office assistant for reports and newsletters; internal tools at SK hynix; quantised models for South Korea's Ministry of National Defense; and drug research with SK Biopharmaceuticals. In June 2026 SKT signed agreements with KG Steel and KONEC to pilot AI agents in factories. Its consortium, with Krafton, 42dot, Rebellions, Liner, SelectStar, Seoul National University and KAIST, passed the second stage of Korea's sovereign AI foundation-model programme in August 2026, with a final evaluation due by the end of the year.
A.X K2, K1, 3.1 and 4.0 Light are free on Hugging Face under the Apache 2.0 licence, A.X 4.0 under the Qwen licence, and SKT also publishes quantised builds. There is no self-serve public API or price list; enterprise and lightweight-model access is arranged through SKT, and API access has gone to government-programme participants and selected start-ups.
It is most relevant to Korean-language applications and to organisations wanting large open-weight models.
Compiled by RECATOOLS from public sources: vendor documentation and pricing, code repositories and published reporting.
Notable facts
- A.X K1's 519B total parameters activate only 33B at a time per token — making it as computationally efficient as a ~33B dense model while retaining the knowledge capacity of a 519B one.
- SK Telecom's A-dot AI assistant blocked approximately 1.1 billion voice-phishing and spam call attempts in 2025 alone — more than 3 million fraudulent calls stopped per day.
- The GTAA telco alliance (SKT + Deutsche Telekom + e& + Singtel + SoftBank) collectively reaches an estimated 1.3 billion mobile subscribers across 50 countries — larger than the population of any single nation except China or India.
- Despite being a telecom company, SKT trained A.X 3.1 entirely in-house — model architecture, data curation, and training — on its own TITAN supercomputing cluster, without relying on any external base model.
Frequently asked questions
About this listing
This entry was compiled from publicly available data including SK Telecom A.X's official website, press releases, documentation, and reputable third-party publications. RECATOOLS is not affiliated with SK Telecom A.X unless explicitly stated.
Third-party AI tools update their pricing, features, availability, and policies frequently. Information here may be outdated by the time you read this — we make reasonable efforts to keep listings current, but cannot guarantee absolute accuracy.
For the latest details, please refer to SK Telecom A.X directly →
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