Kimi K2.6 vs Qwen3.8 27B vs Grok 4.20 (Reasoning)
Too close to call on our weighted score (Grok 4.20 (Reasoning) 67, Qwen3.8 27B 66, Kimi K2.6 64). The right pick depends on what you value most.
Moonshot AIKimi K2.6
64/100- ECI151.1
- Price$0.95 / $4.00
- Context262K
Alibaba (Qwen)Qwen3.8 27B
66/100- ECI151.8
- Price$0.40 / $2.55
- Context262K
xAIGrok 4.20 (Reasoning)
67/100- ECI152.3
- Price$1.25 / $2.50
- Context1M
Too close to call
It is close. Our weighted score puts them within 2 points (Grok 4.20 (Reasoning) 67/100, Qwen3.8 27B 66/100, Kimi K2.6 64/100), so choose by what matters most for your work: Grok 4.20 (Reasoning) for raw capability and Qwen3.8 27B on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGrok 4.20 (Reasoning)Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.3 · Qwen3.8 27B 151.8 · Kimi K2.6 151.1
- Lowest priceQwen3.8 27BQwen3.8 27B $0.938 · Grok 4.20 (Reasoning) $1.56 · Kimi K2.6 $1.71 per 1M tokens (3:1 blend)
- Longest contextGrok 4.20 (Reasoning)Grok 4.20 (Reasoning) 1,000,000 · Kimi K2.6 262,144 · Qwen3.8 27B 262,144 tokens
- Widest inputsSame inputsKimi K2.6: Text, Images, Video · Qwen3.8 27B: Text, Images, Video · Grok 4.20 (Reasoning): Text, Images, PDFs
- Self-hostingKimi K2.6 and Qwen3.8 27BPublishes downloadable weights
| Measure | Weight | Kimi K2.6 | Qwen3.8 27B | Grok 4.20 (Reasoning) |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 78 | 79 | 79 |
| Price | 25% | 37 | 49 | 39 |
| Inputs & features | 15% | 80 | 70 | 80 |
| Context window | 10% | 37 | 37 | 60 |
| Overall | 100% | 64/100 | 66/100 | 67/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Kimi K2.6Moonshot AI | Qwen3.8 27BAlibaba (Qwen) | Grok 4.20 (Reasoning)xAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 151.1 | 151.8 | 152.3 (best) |
| ECI rank | #55 of 165 | #54 of 165 | #51 of 165 (best) |
| GPQA DiamondGraduate-level science questions | 90.8% (best) | — | 89.3% |
| FrontierMath Tiers 1–3Research-level mathematics | 57.2% (best) | — | 44.9% |
| OTIS Mock AIME 2024–2025Competition mathematics | 96.1% (best) | — | 92.2% |
| SWE-bench VerifiedFixing real GitHub issues | 76.7% | — | — |
| SimpleQA VerifiedShort factual questions | 34.9% (best) | — | 30.2% |
| Price per million tokens | |||
| Input | $0.95 | $0.40 (best) | $1.25 |
| Output | $4.00 | $2.55 | $2.50 (best) |
| Cached input | $0.16 (best) | — | $0.20 |
| Blended (3:1) | $1.71 | $0.938 (best) | $1.56 |
| Long-context rate | Same rate | Same rate | Over 200K: $2.50 / $5.00 |
| Price source | Official Moonshot AI API | Median of 49 providers | Official xAI API |
| Limits | |||
| Context window | 262,144 tokens | 262,144 tokens | 1,000,000 tokens (best) |
| Max output | 262,144 tokens (best) | 32,768 tokens | 30,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | No | Yes |
| Audio | No | No | No |
| Video | Yes | Yes | No |
| Reasoning | Yes | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | No | Yes |
| Availability | |||
| Weights | Open | Open | Proprietary |
| API model ID | kimi-k2.6 | — | grok-4.20-0309-reasoning |
| API providers | 60 (best) | 53 | 15 |
| Released | Apr 20, 2026 | Aug 14, 2026 | Mar 9, 2026 |
| Knowledge cutoff | Jan 2025 | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Kimi K2.6$17.50
- Qwen3.8 27B$9.10
- Grok 4.20 (Reasoning)$17.50
Which should you choose?
Which is better: Kimi K2.6, Qwen3.8 27B or Grok 4.20 (Reasoning)?
It is close. Our weighted score puts them within 2 points (Grok 4.20 (Reasoning) 67/100, Qwen3.8 27B 66/100, Kimi K2.6 64/100), so choose by what matters most for your work: Grok 4.20 (Reasoning) for raw capability and Qwen3.8 27B on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Kimi K2.6, Qwen3.8 27B or Grok 4.20 (Reasoning)?
Qwen3.8 27B is cheaper at $0.40 input / $2.55 output per million tokens (median across 49 API providers). Grok 4.20 (Reasoning) costs $1.25 input / $2.50 output per million tokens (official xAI API price); Kimi K2.6 costs $0.95 input / $4.00 output per million tokens (official Moonshot AI API price). At a typical mix of three input tokens to one output token, that is $0.938 per million tokens for Qwen3.8 27B versus $1.56 for Grok 4.20 (Reasoning) (1.7× as much) and $1.71 for Kimi K2.6 (1.8× as much).
Which scores higher on benchmarks?
Grok 4.20 (Reasoning) scores higher on the Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.3 (#51 of 165), Qwen3.8 27B 151.8 (#54 of 165) and Kimi K2.6 151.1 (#55 of 165). The confidence ranges of the top two overlap (149.5–154.7 vs 149.9–153.6), so treat the gap as small.
Which is better for coding?
There are no published SWE-bench Verified results for Qwen3.8 27B and Grok 4.20 (Reasoning) yet, so there is no like-for-like coding score. On overall capability, Grok 4.20 (Reasoning) leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
Grok 4.20 (Reasoning) has the largest context window at 1,000,000 tokens, against 262,144 for Kimi K2.6 and 262,144 for Qwen3.8 27B. Maximum output per response: Kimi K2.6 up to 262,144, Qwen3.8 27B up to 32,768, Grok 4.20 (Reasoning) up to 30,000 tokens.
Which can read images, PDFs, audio or video?
Kimi K2.6 accepts text, images and video; Qwen3.8 27B accepts text, images and video; Grok 4.20 (Reasoning) accepts text, images and PDFs. They handle the same number of input types.
Are any of these open source?
Kimi K2.6 and Qwen3.8 27B publishes its weights and can be self-hosted; Grok 4.20 (Reasoning) is proprietary.
Which is newer?
Qwen3.8 27B is the newest, released Aug 14, 2026. Kimi K2.6 came out Apr 20, 2026; Grok 4.20 (Reasoning) came out Mar 9, 2026. Knowledge cutoff: Kimi K2.6 Jan 2025.
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
- Kimi K2.6 vs GLM-5.1Z.ai (Zhipu) · ECI 149.9
- Kimi K2.6 vs GPT-5.4 miniOpenAI · ECI 148.8
- Kimi K2.6 vs InklingThinking Machines · ECI 148.5
- Qwen3.8 27B vs Inkling SmallThinking Machines · ECI 150.5
- Qwen3.8 27B vs Mistral Large 4Mistral AI · ECI 150.6
- Qwen3.8 27B vs DeepSeek V4 Pro 0813DeepSeek · ECI 155.9
