GPT-4.1 vs Kimi K2 Instruct
Too close to call on our weighted score (GPT-4.1 52, Kimi K2 Instruct 50). The right pick depends on what you value most.
OpenAIGPT-4.1
52/100- ECI136.7
- Price$2.00 / $8.00
- Context1.05M
Moonshot AIKimi K2 Instruct
50/100- ECI139.9
- Price$0.57 / $2.30
- Context131K
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within 2 points (GPT-4.1 52/100, Kimi K2 Instruct 50/100), so choose by what matters most for your work: Kimi K2 Instruct for raw capability and GPT-4.1 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityKimi K2 InstructCapabilities Index (ECI): Kimi K2 Instruct 139.9 · GPT-4.1 136.7
- Lowest priceKimi K2 InstructKimi K2 Instruct $1.00 · GPT-4.1 $3.50 per 1M tokens (3:1 blend)
- Longest contextGPT-4.1GPT-4.1 1,047,576 · Kimi K2 Instruct 131,072 tokens
- Widest inputsGPT-4.1GPT-4.1: Text, Images, PDFs · Kimi K2 Instruct: Text
- Self-hostingKimi K2 InstructPublishes downloadable weights (Modified MIT)
| Measure | Weight | GPT-4.1 | Kimi K2 Instruct |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 60 | 64 |
| Price | 25% | 23 | 48 |
| Inputs & features | 15% | 70 | 25 |
| Context window | 10% | 61 | 25 |
| Overall | 100% | 52/100 | 50/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-4.1OpenAI | Kimi K2 InstructMoonshot AI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 136.7 | 139.9 (best) |
| ECI rank | #125 of 165 | #112 of 165 (best) |
| GPQA DiamondGraduate-level science questions | 66.9% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 6.0% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 38.3% | — |
| SWE-bench VerifiedFixing real GitHub issues | 48.5% | — |
| SimpleQA VerifiedShort factual questions | 31.1% | — |
| Price per million tokens | ||
| Input | $2.00 | $0.57 (best) |
| Output | $8.00 | $2.30 (best) |
| Cached input | $0.50 | — |
| Blended (3:1) | $3.50 | $1.00 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Median of 11 providers |
| Limits | ||
| Context window | 1,047,576 tokens (best) | 131,072 tokens |
| Max output | 32,768 tokens | 32,768 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | Yes | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | No | No |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | OpenModified MIT |
| API model ID | gpt-4.1 | — |
| API providers | 31 (best) | 11 |
| Released | Apr 14, 2025 | Jul 11, 2025 |
| Knowledge cutoff | Apr 2024 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-4.1$36.00
- Kimi K2 Instruct$10.30
Which should you choose?
Which is better: GPT-4.1 or Kimi K2 Instruct?
It is close. Our weighted score puts them within 2 points (GPT-4.1 52/100, Kimi K2 Instruct 50/100), so choose by what matters most for your work: Kimi K2 Instruct for raw capability and GPT-4.1 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-4.1 or Kimi K2 Instruct?
Kimi K2 Instruct is cheaper at $0.57 input / $2.30 output per million tokens (median across 11 API providers). GPT-4.1 costs $2.00 input / $8.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.00 per million tokens for Kimi K2 Instruct versus $3.50 for GPT-4.1 (3.5× 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-4.1 136.7 (#125 of 165). The confidence ranges of the top two overlap (136.3–141.6 vs 134.0–138.5), so treat the gap as small.
Which is better for coding?
There are no published SWE-bench Verified results for Kimi K2 Instruct 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?
GPT-4.1 has the largest context window at 1,047,576 tokens, against 131,072 for Kimi K2 Instruct. Maximum output per response: GPT-4.1 up to 32,768, Kimi K2 Instruct up to 32,768 tokens.
Which can read images, PDFs, audio or video?
GPT-4.1 accepts text, images and PDFs; Kimi K2 Instruct accepts text. GPT-4.1 handles the widest range of inputs.
Are any of these open source?
Kimi K2 Instruct publishes its weights (Modified MIT) and can be self-hosted; GPT-4.1 is proprietary.
Which is newer?
Kimi K2 Instruct is the newest, released Jul 11, 2025. GPT-4.1 came out Apr 14, 2025. Knowledge cutoff: GPT-4.1 Apr 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.
Related comparisons
- Add DeepSeek-R1Three-way comparison
- GPT-4.1 vs DeepSeek-R1DeepSeek · ECI 138.8
- GPT-4.1 vs Claude Sonnet 3.7Anthropic · ECI 141.0
- GPT-4.1 vs Gemini 2.5 ProGoogle · ECI 145.3
- GPT-4.1 vs QwQ 32BAlibaba (Qwen) · ECI 137.5
- Kimi K2 Instruct vs Gemini 2.5 FlashGoogle · ECI 140.6
- Kimi K2 Instruct vs DeepSeek R1 0528DeepSeek · ECI 141.2
