ZMIME
Comparison · 2 models · Updated Nov 2, 2026

Kimi K2 Instruct vs GPT OSS 120B

GPT OSS 120B comes out ahead, 58 to 50 on our weighted score, and it is the cheaper option too.

  1. Moonshot AI

    Kimi K2 Instruct

    Released Jul 11, 2025

    50/100
    • ECI139.9
    • Price$0.57 / $2.30
    • Context131K
    Full specs Remove Kimi K2 Instruct
  2. Our pick

    OpenAI

    GPT OSS 120B

    Released Aug 5, 2025

    58/100
    • ECI139.8
    • Price$0.15 / $0.60
    • Context131K
    Full specs Remove GPT OSS 120B

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT OSS 120B is our pick

GPT OSS 120B is the better all-round choice, scoring 58/100 against Kimi K2 Instruct (50). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityKimi K2 InstructCapabilities Index (ECI): Kimi K2 Instruct 139.9 · GPT OSS 120B 139.8
  • Lowest priceGPT OSS 120BGPT OSS 120B $0.263 · Kimi K2 Instruct $1.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameKimi K2 Instruct 131,072 · GPT OSS 120B 131,072 tokens
  • Widest inputsSame inputsKimi K2 Instruct: Text · GPT OSS 120B: Text
  • Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
How the score is built
MeasureWeightKimi K2 InstructGPT OSS 120B
CapabilityCapabilities Index (ECI)50%6464
Price25%4874
Inputs & features15%2535
Context window10%2525
Overall100%50/10058/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Kimi K2 Instruct vs GPT OSS 120B specifications side by side
SpecificationKimi K2 InstructMoonshot AIGPT OSS 120BOpenAI
Capability
Capabilities Index (ECI)139.9 (best)139.8
ECI rank#112 of 165 (best)#114 of 165
GPQA DiamondGraduate-level science questions—75.8%
OTIS Mock AIME 2024–2025Competition mathematics—88.9%
Price per million tokens
Input$0.57$0.15 (best)
Output$2.30$0.60 (best)
Cached input——
Blended (3:1)$1.00$0.263 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 11 providersMedian of 65 providers
Limits
Context window131,072 tokens131,072 tokens
Max output32,768 tokens32,768 tokens
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningNoYes
Tool callingYesYes
Structured outputNoNo
Availability
WeightsOpenModified MITOpen
API model ID——
API providers1167 (best)
ReleasedJul 11, 2025Aug 5, 2025
Knowledge cutoff—Jun 2024
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Kimi K2 Instruct$10.30
  • GPT OSS 120B$2.70
04 — Questions

Which should you choose?

Which is better: Kimi K2 Instruct or GPT OSS 120B?

GPT OSS 120B is the better all-round choice, scoring 58/100 against Kimi K2 Instruct (50). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Kimi K2 Instruct or GPT OSS 120B?

GPT OSS 120B is cheaper at $0.15 input / $0.60 output per million tokens (median across 65 API providers). Kimi K2 Instruct costs $0.57 input / $2.30 output per million tokens (median across 11 API providers). At a typical mix of three input tokens to one output token, that is $0.263 per million tokens for GPT OSS 120B versus $1.00 for Kimi K2 Instruct (3.8× as much).

Which scores higher on benchmarks?

Kimi K2 Instruct scores higher on the Capabilities Index (ECI): Kimi K2 Instruct 139.9 (#112 of 165) and GPT OSS 120B 139.8 (#114 of 165). The confidence ranges of the top two overlap (136.3–141.6 vs 135.6–142.2), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for Kimi K2 Instruct and GPT OSS 120B yet, so there is no like-for-like coding score. On overall capability, Kimi K2 Instruct leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Kimi K2 Instruct and GPT OSS 120B share the same 131,072-token context window. Maximum output per response: Kimi K2 Instruct up to 32,768, GPT OSS 120B up to 32,768 tokens.

Which can read images, PDFs, audio or video?

Kimi K2 Instruct accepts text; GPT OSS 120B accepts text. They handle the same number of input types.

Are any of these open source?

Yes, both publish their weights (Modified MIT), so you can self-host them.

Which is newer?

GPT OSS 120B is the newest, released Aug 5, 2025. Kimi K2 Instruct came out Jul 11, 2025. Knowledge cutoff: GPT OSS 120B Jun 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.

05 — Keep comparing

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