GPT-5.6 Sol vs Grok 4.3 vs Kimi K2.7 Code
Too close to call on our weighted score (Grok 4.3 67, GPT-5.6 Sol 66, Kimi K2.7 Code 64). The right pick depends on what you value most.
OpenAIGPT-5.6 Sol
66/100- ECI161.8
- Price$4.00 / $20.00
- Context1.05M
xAIGrok 4.3
67/100- ECI149.2
- Price$1.25 / $2.50
- Context1M
Moonshot AIKimi K2.7 Code
64/100- ECI150.0
- Price$0.95 / $4.00
- Context262K
Too close to call
It is close. Our weighted score puts them within a point (Grok 4.3 67/100, GPT-5.6 Sol 66/100, Kimi K2.7 Code 64/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Grok 4.3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.6 SolCapabilities Index (ECI): GPT-5.6 Sol 161.8 · Kimi K2.7 Code 150.0 · Grok 4.3 149.2
- Lowest priceGrok 4.3Grok 4.3 $1.56 · Kimi K2.7 Code $1.71 · GPT-5.6 Sol $8.00 per 1M tokens (3:1 blend)
- Longest contextGPT-5.6 SolGPT-5.6 Sol 1,050,000 · Grok 4.3 1,000,000 · Kimi K2.7 Code 262,144 tokens
- Widest inputsSame inputsGPT-5.6 Sol: Text, Images, PDFs · Grok 4.3: Text, Images, PDFs · Kimi K2.7 Code: Text, Images, Video
- Self-hostingKimi K2.7 CodePublishes downloadable weights
| Measure | Weight | GPT-5.6 Sol | Grok 4.3 | Kimi K2.7 Code |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 93 | 77 | 78 |
| Price | 25% | 7 | 41 | 39 |
| Inputs & features | 15% | 80 | 80 | 80 |
| Context window | 10% | 61 | 60 | 37 |
| Overall | 100% | 66/100 | 67/100 | 64/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.6 SolOpenAI | Grok 4.3xAI | Kimi K2.7 CodeMoonshot AI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 161.8 (best) | 149.2 | 150.0 |
| ECI rank | #8 of 148 (best) | #55 of 148 | #49 of 148 |
| GPQA DiamondGraduate-level science questions | 93.5% (best) | 88.8% | 87.9% |
| FrontierMath Tiers 1–3Research-level mathematics | 89.1% (best) | 42.8% | 54.0% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 93.3% | 95.6% |
| SimpleQA VerifiedShort factual questions | 69.7% (best) | 33.2% | 36.5% |
| Price per million tokens | |||
| Input | $4.00 | $1.25 | $0.95 (best) |
| Output | $20.00 | $2.50 (best) | $4.00 |
| Cached input | $0.40 | $0.20 | $0.19 (best) |
| Blended (3:1) | $8.00 | $1.56 (best) | $1.71 |
| Long-context rate | Over 272K: $8.00 / $30.00 | Over 200K: $2.50 / $5.00 | Same rate |
| Price source | Official OpenAI API | Official xAI API | Official Moonshot AI API |
| Limits | |||
| Context window | 1,050,000 tokens (best) | 1,000,000 tokens | 262,144 tokens |
| Max output | 128,000 tokens | 30,000 tokens | 262,144 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | No |
| Audio | No | No | No |
| Video | No | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · medium · high | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Open |
| API model ID | gpt-5.6-sol | grok-4.3 | kimi-k2.7-code |
| API providers | 40 | 27 | 51 (best) |
| Released | Jul 9, 2026 | Apr 17, 2026 | Jun 12, 2026 |
| Knowledge cutoff | Feb 16, 2026 | — | 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.
- GPT-5.6 Sol$80.00
- Grok 4.3$17.50
- Kimi K2.7 Code$17.50
Which should you choose?
Which is better: GPT-5.6 Sol, Grok 4.3 or Kimi K2.7 Code?
It is close. Our weighted score puts them within a point (Grok 4.3 67/100, GPT-5.6 Sol 66/100, Kimi K2.7 Code 64/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Grok 4.3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.6 Sol, Grok 4.3 or Kimi K2.7 Code?
Grok 4.3 is cheaper at $1.25 input / $2.50 output per million tokens (official xAI API price). Kimi K2.7 Code costs $0.95 input / $4.00 output per million tokens (official Moonshot AI API price); GPT-5.6 Sol costs $4.00 input / $20.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.56 per million tokens for Grok 4.3 versus $1.71 for Kimi K2.7 Code (1.1× as much) and $8.00 for GPT-5.6 Sol (5.1× as much).
Which scores higher on benchmarks?
GPT-5.6 Sol scores higher on the Capabilities Index (ECI): GPT-5.6 Sol 161.8 (#8 of 148), Kimi K2.7 Code 150.0 (#49 of 148) and Grok 4.3 149.2 (#55 of 148). Their confidence ranges do not overlap (159.3–165.3 vs 148.1–151.8), so the gap is a real one. On individual benchmarks: GPQA Diamond — GPT-5.6 Sol 93.5%, Grok 4.3 88.8%, Kimi K2.7 Code 87.9%; FrontierMath Tiers 1–3 — GPT-5.6 Sol 89.1%, Kimi K2.7 Code 54.0%, Grok 4.3 42.8%; OTIS Mock AIME 2024–2025 — GPT-5.6 Sol 100%, Kimi K2.7 Code 95.6%, Grok 4.3 93.3%; SimpleQA Verified — GPT-5.6 Sol 69.7%, Kimi K2.7 Code 36.5%, Grok 4.3 33.2%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.6 Sol, Grok 4.3 and Kimi K2.7 Code yet, so there is no like-for-like coding score. On overall capability, GPT-5.6 Sol 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?
GPT-5.6 Sol has the largest context window at 1,050,000 tokens, against 1,000,000 for Grok 4.3 and 262,144 for Kimi K2.7 Code. Maximum output per response: GPT-5.6 Sol up to 128,000, Grok 4.3 up to 30,000, Kimi K2.7 Code up to 262,144 tokens.
Which can read images, PDFs, audio or video?
GPT-5.6 Sol accepts text, images and PDFs; Grok 4.3 accepts text, images and PDFs; Kimi K2.7 Code accepts text, images and video. They handle the same number of input types.
Are any of these open source?
Kimi K2.7 Code publishes its weights and can be self-hosted; GPT-5.6 Sol and Grok 4.3 is proprietary.
Which is newer?
GPT-5.6 Sol is the newest, released Jul 9, 2026. Kimi K2.7 Code came out Jun 12, 2026; Grok 4.3 came out Apr 17, 2026. Knowledge cutoff: GPT-5.6 Sol Feb 16, 2026, Kimi K2.7 Code 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.
