Kimi K2.6 vs Qwen3.8 Max vs Grok 4.20 (Reasoning)
Too close to call on our weighted score (Qwen3.8 Max 69, Grok 4.20 (Reasoning) 68, Kimi K2.6 65). The right pick depends on what you value most.
Moonshot AIKimi K2.6
65/100- ECI151.1
- Price$0.95 / $4.00
- Context262K
Alibaba (Qwen)Qwen3.8 Max
69/100- ECI156.6
- Price$2.00 / $6.00
- Context1M
xAIGrok 4.20 (Reasoning)
68/100- ECI152.0
- Price$1.25 / $2.50
- Context1M
Too close to call
It is close. Our weighted score puts them within 1 points (Qwen3.8 Max 69/100, Grok 4.20 (Reasoning) 68/100, Kimi K2.6 65/100), so choose by what matters most for your work: Qwen3.8 Max for raw capability and Grok 4.20 (Reasoning) on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityQwen3.8 MaxCapabilities Index (ECI): Qwen3.8 Max 156.6 · Grok 4.20 (Reasoning) 152.0 · Kimi K2.6 151.1
- Lowest priceGrok 4.20 (Reasoning)Grok 4.20 (Reasoning) $1.56 · Kimi K2.6 $1.71 · Qwen3.8 Max $3.00 per 1M tokens (3:1 blend)
- Longest contextQwen3.8 Max and Grok 4.20 (Reasoning)Qwen3.8 Max 1,000,000 · Grok 4.20 (Reasoning) 1,000,000 · Kimi K2.6 262,144 tokens
- Widest inputsQwen3.8 MaxKimi K2.6: Text, Images, Video · Qwen3.8 Max: Text, Images, PDFs, Video · Grok 4.20 (Reasoning): Text, Images, PDFs
- Self-hostingKimi K2.6Publishes downloadable weights
| Measure | Weight | Kimi K2.6 | Qwen3.8 Max | Grok 4.20 (Reasoning) |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 79 | 86 | 81 |
| Price | 25% | 39 | 27 | 41 |
| Inputs & features | 15% | 80 | 90 | 80 |
| Context window | 10% | 37 | 60 | 60 |
| Overall | 100% | 65/100 | 69/100 | 68/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Kimi K2.6Moonshot AI | Qwen3.8 MaxAlibaba (Qwen) | Grok 4.20 (Reasoning)xAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 151.1 | 156.6 (best) | 152.0 |
| ECI rank | #45 of 148 | #20 of 148 (best) | #41 of 148 |
| GPQA DiamondGraduate-level science questions | 90.8% | 92.7% (best) | 89.3% |
| FrontierMath Tiers 1–3Research-level mathematics | 57.2% | 74.7% (best) | 44.9% |
| OTIS Mock AIME 2024–2025Competition mathematics | 96.1% | 99.4% (best) | 92.2% |
| SWE-bench VerifiedFixing real GitHub issues | 76.7% | — | — |
| SimpleQA VerifiedShort factual questions | 34.9% | 45.8% (best) | 30.2% |
| Price per million tokens | |||
| Input | $0.95 (best) | $2.00 | $1.25 |
| Output | $4.00 | $6.00 | $2.50 (best) |
| Cached input | $0.16 (best) | $0.25 | $0.20 |
| Blended (3:1) | $1.71 | $3.00 | $1.56 (best) |
| Long-context rate | Same rate | Same rate | Over 200K: $2.50 / $5.00 |
| Price source | Official Moonshot AI API | Official Alibaba API | Official xAI API |
| Limits | |||
| Context window | 262,144 tokens | 1,000,000 tokens (best) | 1,000,000 tokens (best) |
| Max output | 262,144 tokens (best) | 131,072 tokens | 30,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | Yes | Yes |
| Audio | No | No | No |
| Video | Yes | Yes | No |
| Reasoning | Yes | Yeslow · medium · xhigh | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Open | Proprietary | Proprietary |
| API model ID | kimi-k2.6 | qwen3.8-max | grok-4.20-0309-reasoning |
| API providers | 46 (best) | 25 | 11 |
| Released | Apr 21, 2026 | Aug 3, 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 Max$32.00
- Grok 4.20 (Reasoning)$17.50
Which should you choose?
Which is better: Kimi K2.6, Qwen3.8 Max or Grok 4.20 (Reasoning)?
It is close. Our weighted score puts them within 1 points (Qwen3.8 Max 69/100, Grok 4.20 (Reasoning) 68/100, Kimi K2.6 65/100), so choose by what matters most for your work: Qwen3.8 Max for raw capability and Grok 4.20 (Reasoning) on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Kimi K2.6, Qwen3.8 Max or Grok 4.20 (Reasoning)?
Grok 4.20 (Reasoning) is cheaper at $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); Qwen3.8 Max costs $2.00 input / $6.00 output per million tokens (official Alibaba API price). At a typical mix of three input tokens to one output token, that is $1.56 per million tokens for Grok 4.20 (Reasoning) versus $1.71 for Kimi K2.6 (1.1× as much) and $3.00 for Qwen3.8 Max (1.9× as much).
Which scores higher on benchmarks?
Qwen3.8 Max scores higher on the Capabilities Index (ECI): Qwen3.8 Max 156.6 (#20 of 148), Grok 4.20 (Reasoning) 152.0 (#41 of 148) and Kimi K2.6 151.1 (#45 of 148). Their confidence ranges do not overlap (154.5–158.8 vs 149.3–154.4), so the gap is a real one. On individual benchmarks: GPQA Diamond — Qwen3.8 Max 92.7%, Kimi K2.6 90.8%, Grok 4.20 (Reasoning) 89.3%; FrontierMath Tiers 1–3 — Qwen3.8 Max 74.7%, Kimi K2.6 57.2%, Grok 4.20 (Reasoning) 44.9%; OTIS Mock AIME 2024–2025 — Qwen3.8 Max 99.4%, Kimi K2.6 96.1%, Grok 4.20 (Reasoning) 92.2%; SimpleQA Verified — Qwen3.8 Max 45.8%, Kimi K2.6 34.9%, Grok 4.20 (Reasoning) 30.2%.
Which is better for coding?
There are no published SWE-bench Verified results for Qwen3.8 Max and Grok 4.20 (Reasoning) yet, so there is no like-for-like coding score. On overall capability, Qwen3.8 Max 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?
Qwen3.8 Max and Grok 4.20 (Reasoning) have the largest context windows (1,000,000 and 1,000,000 tokens), against 262,144 for Kimi K2.6. Maximum output per response: Kimi K2.6 up to 262,144, Qwen3.8 Max up to 131,072, 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 Max accepts text, images, PDFs and video; Grok 4.20 (Reasoning) accepts text, images and PDFs. Qwen3.8 Max handles the widest range of inputs.
Are any of these open source?
Kimi K2.6 publishes its weights and can be self-hosted; Qwen3.8 Max and Grok 4.20 (Reasoning) is proprietary.
Which is newer?
Qwen3.8 Max is the newest, released Aug 3, 2026. Kimi K2.6 came out Apr 21, 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 Oct 4, 2026.
