GPT-5.4 mini vs GPT-5.6 Sol vs Grok 4.3
Too close to call on our weighted score (Grok 4.3 67, GPT-5.6 Sol 66, GPT-5.4 mini 63). The right pick depends on what you value most.
OpenAIGPT-5.4 mini
63/100- ECI148.8
- Price$0.75 / $4.50
- Context400K
- OpenAI
GPT-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
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, GPT-5.4 mini 63/100), 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 · Grok 4.3 149.2 · GPT-5.4 mini 148.8
- Lowest priceGrok 4.3Grok 4.3 $1.56 · GPT-5.4 mini $1.69 · 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 · GPT-5.4 mini 400,000 tokens
- Widest inputsGPT-5.6 Sol and Grok 4.3GPT-5.4 mini: Text, Images · GPT-5.6 Sol: Text, Images, PDFs · Grok 4.3: Text, Images, PDFs
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | GPT-5.4 mini | GPT-5.6 Sol | Grok 4.3 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 77 | 93 | 77 |
| Price | 25% | 39 | 7 | 41 |
| Inputs & features | 15% | 70 | 80 | 80 |
| Context window | 10% | 44 | 61 | 60 |
| Overall | 100% | 63/100 | 66/100 | 67/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.4 miniOpenAI | GPT-5.6 SolOpenAI | Grok 4.3xAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 148.8 | 161.8 (best) | 149.2 |
| ECI rank | #56 of 148 | #8 of 148 (best) | #55 of 148 |
| GPQA DiamondGraduate-level science questions | 86.9% | 93.5% (best) | 88.8% |
| FrontierMath Tiers 1–3Research-level mathematics | 51.2% | 89.1% (best) | 42.8% |
| OTIS Mock AIME 2024–2025Competition mathematics | 88.9% | 100% (best) | 93.3% |
| SimpleQA VerifiedShort factual questions | 29.4% | 69.7% (best) | 33.2% |
| Price per million tokens | |||
| Input | $0.75 (best) | $4.00 | $1.25 |
| Output | $4.50 | $20.00 | $2.50 (best) |
| Cached input | $0.075 (best) | $0.40 | $0.20 |
| Blended (3:1) | $1.69 | $8.00 | $1.56 (best) |
| Long-context rate | Same rate | Over 272K: $8.00 / $30.00 | Over 200K: $2.50 / $5.00 |
| Price source | Official OpenAI API | Official OpenAI API | Official xAI API |
| Limits | |||
| Context window | 400,000 tokens | 1,050,000 tokens (best) | 1,000,000 tokens |
| Max output | 128,000 tokens (best) | 128,000 tokens (best) | 30,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | Yes | Yes |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yeslow · medium · high · xhigh | Yeslow · medium · high · xhigh · max | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | gpt-5.4-mini | gpt-5.6-sol | grok-4.3 |
| API providers | 29 | 40 (best) | 27 |
| Released | Mar 17, 2026 | Jul 9, 2026 | Apr 17, 2026 |
| Knowledge cutoff | Aug 31, 2025 | 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.
- GPT-5.4 mini$16.50
- GPT-5.6 Sol$80.00
- Grok 4.3$17.50
Which should you choose?
Which is better: GPT-5.4 mini, GPT-5.6 Sol or Grok 4.3?
It is close. Our weighted score puts them within a point (Grok 4.3 67/100, GPT-5.6 Sol 66/100, GPT-5.4 mini 63/100), 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-5.4 mini, GPT-5.6 Sol or Grok 4.3?
Grok 4.3 is cheaper at $1.25 input / $2.50 output per million tokens (official xAI API price). GPT-5.4 mini costs $0.75 input / $4.50 output per million tokens (official OpenAI 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 $1.69 for GPT-5.4 mini (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), Grok 4.3 149.2 (#55 of 148) and GPT-5.4 mini 148.8 (#56 of 148). Their confidence ranges do not overlap (159.3–165.3 vs 147.6–150.8), so the gap is a real one. On individual benchmarks: GPQA Diamond — GPT-5.6 Sol 93.5%, Grok 4.3 88.8%, GPT-5.4 mini 86.9%; FrontierMath Tiers 1–3 — GPT-5.6 Sol 89.1%, GPT-5.4 mini 51.2%, Grok 4.3 42.8%; OTIS Mock AIME 2024–2025 — GPT-5.6 Sol 100%, Grok 4.3 93.3%, GPT-5.4 mini 88.9%; SimpleQA Verified — GPT-5.6 Sol 69.7%, Grok 4.3 33.2%, GPT-5.4 mini 29.4%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.4 mini, GPT-5.6 Sol and Grok 4.3 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 400,000 for GPT-5.4 mini. Maximum output per response: GPT-5.4 mini up to 128,000, GPT-5.6 Sol up to 128,000, Grok 4.3 up to 30,000 tokens.
Which can read images, PDFs, audio or video?
GPT-5.4 mini accepts text and images; GPT-5.6 Sol accepts text, images and PDFs; Grok 4.3 accepts text, images and PDFs. GPT-5.6 Sol handles the widest range of inputs.
Are any of these open source?
No. GPT-5.4 mini, GPT-5.6 Sol and Grok 4.3 are proprietary and only available through APIs and apps.
Which is newer?
GPT-5.6 Sol is the newest, released Jul 9, 2026. Grok 4.3 came out Apr 17, 2026; GPT-5.4 mini came out Mar 17, 2026. Knowledge cutoff: GPT-5.4 mini Aug 31, 2025, 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.
