Grok 4.6 vs GPT-5.6 Sol
Too close to call on our weighted score (GPT-5.6 Sol 66, Grok 4.6 65). The right pick depends on what you value most.
xAIGrok 4.6
65/100- ECI156.6
- Price$2.00 / $6.00
- Context500K
OpenAIGPT-5.6 Sol
66/100- ECI161.8
- Price$4.00 / $20.00
- Context1.05M
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within 1 points (GPT-5.6 Sol 66/100, Grok 4.6 65/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Grok 4.6 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 · Grok 4.6 156.6
- Lowest priceGrok 4.6Grok 4.6 $3.00 · GPT-5.6 Sol $8.00 per 1M tokens (3:1 blend)
- Longest contextGPT-5.6 SolGPT-5.6 Sol 1,050,000 · Grok 4.6 500,000 tokens
- Widest inputsGPT-5.6 SolGrok 4.6: Text, Images · GPT-5.6 Sol: Text, Images, PDFs
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Grok 4.6 | GPT-5.6 Sol |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 86 | 93 |
| Price | 25% | 27 | 7 |
| Inputs & features | 15% | 70 | 80 |
| Context window | 10% | 48 | 61 |
| Overall | 100% | 65/100 | 66/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Grok 4.6xAI | GPT-5.6 SolOpenAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 156.6 | 161.8 (best) |
| ECI rank | #19 of 148 | #8 of 148 (best) |
| GPQA DiamondGraduate-level science questions | 94.0% (best) | 93.5% |
| FrontierMath Tiers 1–3Research-level mathematics | 66.0% | 89.1% (best) |
| OTIS Mock AIME 2024–2025Competition mathematics | 99.2% | 100% (best) |
| SimpleQA VerifiedShort factual questions | 49.3% | 69.7% (best) |
| Price per million tokens | ||
| Input | $2.00 (best) | $4.00 |
| Output | $6.00 (best) | $20.00 |
| Cached input | $0.50 | $0.40 (best) |
| Blended (3:1) | $3.00 (best) | $8.00 |
| Long-context rate | Over 200K: $4.00 / $12.00 | Over 272K: $8.00 / $30.00 |
| Price source | Official xAI API | Official OpenAI API |
| Limits | ||
| Context window | 500,000 tokens | 1,050,000 tokens (best) |
| Max output | 500,000 tokens (best) | 128,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high · xhigh | Yeslow · medium · high · xhigh · max |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | grok-4.6 | gpt-5.6-sol |
| API providers | 29 | 40 (best) |
| Released | Aug 12, 2026 | Jul 9, 2026 |
| Knowledge cutoff | Feb 1, 2026 | Feb 16, 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Grok 4.6$32.00
- GPT-5.6 Sol$80.00
Which should you choose?
Which is better: Grok 4.6 or GPT-5.6 Sol?
It is close. Our weighted score puts them within 1 points (GPT-5.6 Sol 66/100, Grok 4.6 65/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Grok 4.6 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Grok 4.6 or GPT-5.6 Sol?
Grok 4.6 is cheaper at $2.00 input / $6.00 output per million tokens (official xAI 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 $3.00 per million tokens for Grok 4.6 versus $8.00 for GPT-5.6 Sol (2.7× 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) and Grok 4.6 156.6 (#19 of 148). Their confidence ranges do not overlap (159.3–165.3 vs 154.7–158.9), so the gap is a real one. On individual benchmarks: GPQA Diamond — Grok 4.6 94.0%, GPT-5.6 Sol 93.5%; FrontierMath Tiers 1–3 — GPT-5.6 Sol 89.1%, Grok 4.6 66.0%; OTIS Mock AIME 2024–2025 — GPT-5.6 Sol 100%, Grok 4.6 99.2%; SimpleQA Verified — GPT-5.6 Sol 69.7%, Grok 4.6 49.3%.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4.6 and GPT-5.6 Sol 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. Both 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 500,000 for Grok 4.6. Maximum output per response: Grok 4.6 up to 500,000, GPT-5.6 Sol up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Grok 4.6 accepts text and images; GPT-5.6 Sol accepts text, images and PDFs. GPT-5.6 Sol handles the widest range of inputs.
Are any of these open source?
No. Grok 4.6 and GPT-5.6 Sol are proprietary and only available through APIs and apps.
Which is newer?
Grok 4.6 is the newest, released Aug 12, 2026. GPT-5.6 Sol came out Jul 9, 2026. Knowledge cutoff: Grok 4.6 Feb 1, 2026, GPT-5.6 Sol Feb 16, 2026.
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.
