gpt-oss-120b vs Kimi K2.6

OpenAI · US  |  Moonshot AI · China · Updated June 2026

Quick verdict

Pick gpt-oss-120b for self-hostable on a single 80gb h100 gpu via mxfp4 or configurable reasoning depth (low/medium/high). Pick Kimi K2.6 for open-weight agentic coding and long-horizon tasks or multi-agent swarms (scales to ~300 sub-agents). On a tight budget at scale, gpt-oss-120b is the value pick.

gpt-oss-120b (OpenAI, US) and Kimi K2.6 (Moonshot AI, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. gpt-oss-120b is openAI's open-weight 117B-parameter MoE reasoning model (5.1B active) that runs on a single 80GB GPU and approaches o4-mini on reasoning, coding, and tool use. Kimi K2.6 is moonshot's open-weight 1T-parameter (32B active) MoE model — frontier-class agentic coding you can download and self-host. They diverge most on price, context window and coding benchmarks — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

Specgpt-oss-120bKimi K2.6
ProviderOpenAI (US) Moonshot AI (China)
ReleasedAugust 5, 2025 April 20, 2026
Context window131K (~197 pages) 256K (~393 pages)
Price (in/out)Open weight (self-host / free) $0.6/$2.5 per 1M tokens
Open weight?Yes — self-hostable Yes — self-hostable
Modalitiestext, code text, image, video, code
SWE-Bench Verified62.4% 80.2%
MRCR v2 @ 1MNot published Not published

Who wins what

Self-hostable on a single 80GB H100 GPU via MXFP4

gpt-oss-120b

A core design strength of gpt-oss-120b.

Configurable reasoning depth (low/medium/high)

gpt-oss-120b

A core design strength of gpt-oss-120b.

Agentic tool use, function calling, and code execution

gpt-oss-120b

A core design strength of gpt-oss-120b.

Open-weight agentic coding and long-horizon tasks

Kimi K2.6

A core design strength of Kimi K2.6.

Multi-agent swarms (scales to ~300 sub-agents)

Kimi K2.6

A core design strength of Kimi K2.6.

Self-hosting and data-residency control

Kimi K2.6

A core design strength of Kimi K2.6.

Lowest cost at scale

gpt-oss-120b

At Open weight (self-host / free), it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Kimi K2.6

Its 256K window is about 2× larger, fitting roughly 393 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

gpt-oss-120b

At Open weight (self-host / free) it undercuts Kimi K2.6, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Kimi K2.6

Larger 256K window fits more in one prompt.

Anyone whose priority is self-hostable on a single 80gb h100 gpu via mxfp4

gpt-oss-120b

It is specifically built for that.

Anyone whose priority is open-weight agentic coding and long-horizon tasks

Kimi K2.6

That is its strongest area.

An enterprise with regional data-residency rules

gpt-oss-120b or Kimi K2.6

Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

gpt-oss-120b: where it fits

OpenAI's open-weight 117B-parameter MoE reasoning model (5.1B active) that runs on a single 80GB GPU and approaches o4-mini on reasoning, coding, and tool use. Released August 5, 2025 by OpenAI, it is built for self-hostable on a single 80GB H100 GPU via MXFP4, configurable reasoning depth (low/medium/high), agentic tool use, function calling, and code execution, and full chain-of-thought visibility for debugging.

Its trade-offs are real: text-only, no image, audio, or video input, and 131K context and 5.1B active params trail the largest frontier closed models. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

Kimi K2.6: where it fits

Moonshot's open-weight 1T-parameter (32B active) MoE model — frontier-class agentic coding you can download and self-host. Released April 20, 2026 by Moonshot AI, it is built for open-weight agentic coding and long-horizon tasks, multi-agent swarms (scales to ~300 sub-agents), self-hosting and data-residency control, and strong price-to-performance across many API providers.

Its trade-offs: 256K context trails the 1M Claude and Gemini flagships, weaker on single-turn vision and grounded multimodal tasks, and chinese-jurisdiction data and newer vendor track record. At $0.6 in / $2.5 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

This is less "which is smarter" and more "which ecosystem fits." gpt-oss-120b (US) and Kimi K2.6 (China) differ on pricing philosophy, data-residency, and tooling as much as on raw scores. gpt-oss-120b is the cheaper option, which matters at volume. The pragmatic move is to run one real task through both and judge the outputs against your own constraints — including where your data is allowed to be processed.

Want both gpt-oss-120b and Kimi K2.6 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is gpt-oss-120b or Kimi K2.6 better for coding?

On SWE-Bench Verified, gpt-oss-120b scores 62.4% and Kimi K2.6 scores 80.2% — Kimi K2.6 has the measurable edge.

Which is cheaper, gpt-oss-120b or Kimi K2.6?

gpt-oss-120b is cheaper — Open weight (self-host / free) vs $0.6/$2.5 per 1M tokens.

Which has the bigger context window?

Kimi K2.6 — 256K vs 131K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both gpt-oss-120b and Kimi K2.6 together?

Yes — a multi-model platform like LumiChats gives you gpt-oss-120b, Kimi K2.6 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, gpt-oss-120b or Kimi K2.6?

Kimi K2.6 — released April 20, 2026, about 9 months after gpt-oss-120b.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.