AI Models · Open-Source vs Paid

Kimi K3 Open vs GPT-4.1 Paid

Kimi K3 vs GPT-4.1 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Kimi K3OpenMoonshot AI
$0.79 /M input
$15 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window1M tokens
MultimodalYes
Self-hostYes
GPT-4.1PaidOpenAI
$2 /M input
$8 /M outputManaged API (no infra to run)
TypeProprietary
Context window1M tokens
MultimodalYes
Self-hostNo
Choose Kimi K3 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-4.1 if you want frontier capability through a managed API with zero infrastructure to run.

Kimi K3 vs GPT-4.1 specs

SpecKimi K3GPT-4.1Winner
MakerMoonshot AIOpenAI–
TypeOpen-weightProprietaryKimi K3
Context window1M tokens1M tokensKimi K3
Input price$0.79/M · free self-host$2/MKimi K3
Output price$15/M · free self-host$8/MGPT-4.1
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Kimi K3
LicenseModified MITProprietaryKimi K3

Price gap & when to choose each

1.9×cheaper per output token

GPT-4.1 is ~1.9× cheaper than Kimi K3 on output tokens ($8 vs $15 per M tokens).

Choose Kimi K3 if…
  • You want to self-host or run on your cloud
  • You need the longer 1M context window
  • You prioritize data privacy & control
  • You are building open or reproducible AI
Choose GPT-4.1 if…
  • You want frontier performance through a managed API
  • You want the lower output price
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityKimi K3GPT-4.1
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Kimi K3 vs GPT-4.1

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Kimi K3 delivers 2× more intelligence per dollar.
Kimi K3
GPT-4.1
Intelligence index
43.6
12.7
Coding index
76.2
–
GPQA
93.5%
66.6%
Humanity's Last Exam
46.9%
4.2%
Long Context Reasoning
88.7%
68.3%
SciCode
59.5%
–
τ-Bench Banking
46%
–
Terminal-Bench
85%
–
Math index
–
34.7
MMLU-Pro
–
80.6%
LiveCodeBench
–
45.7%
MATH-500
–
91.3%
AIME
–
43.7%
AIME 2025
–
34.7%
IFBench
–
43%
τ²-Bench
–
47.1%
Terminal-Bench Hard
–
13.6%
Speed
45.2 tok/s
0 tok/s
Latency
2.29s
0s
Intelligence per $
7.3
3.6

Benchmark data by Artificial Analysis.

How Kimi K3 and GPT-4.1 score

🏆 Best value & openness: Kimi K3 (4.6 vs 3.2 / 5)
CriterionKimi K3GPT-4.1
Cost-efficiency3.03.5
Context window5.05.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Kimi K3 Open

Moonshot AI · Open-weight

Kimi K3 is a 2.8T parameter open-weight multimodal reasoning model from Moonshot AI. It is suited for complex coding, knowledge work, and long-horizon agentic workflows, and is particularly strong at...

GPT-4.1 Paid

OpenAI · Proprietary

GPT-4.1 is a flagship large language model optimized for advanced instruction following, real-world software engineering, and long-context reasoning. It supports a 1 million token context window and outperforms GPT-4o and...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Kimi K3 (batch)Kimi K2.6Kimi K2.7 CodeKimi K2.5Kimi K2 ThinkingKimi K2 0905Kimi K2 0711
Other variants tracked
GPT-4.1 (batch)GPT-4.1 MiniGPT-4.1 Mini (batch)GPT-4.1 NanoGPT-4.1 Nano (batch)

Frequently asked questions

Is Kimi K3 as good as GPT-4.1?

Kimi K3 is open-weight and competitive on many tasks, but GPT-4.1 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Kimi K3 locally?

Yes. Kimi K3 has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-4.1 is API-only and cannot be self-hosted.

Kimi K3 vs GPT-4.1 — which should I pick in 2026?

Choose Kimi K3 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-4.1 if you want frontier capability through a managed API with zero infrastructure to run.

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