Grok 4 Fast Reasoning vs Solar Pro 3 vs GLM-4.6V-Flash
Grok 4 Fast Reasoning comes out ahead, 75 to 63 and 53 on our weighted score, though Solar Pro 3 is 9% cheaper per token.
- Our pick
xAIGrok 4 Fast Reasoning
75/100- ECI—
- Price$0.20 / $0.50
- Context2M
UpstageSolar Pro 3
53/100- ECI—
- Price$0.25 / $0.25
- Context131K
Z.ai (Zhipu)GLM-4.6V-Flash
63/100- ECI—
- Price$0.161 / $0.559
- Context128K
Grok 4 Fast Reasoning is our pick
Grok 4 Fast Reasoning is the better all-round choice, scoring 75/100 against GLM-4.6V-Flash (63) and Solar Pro 3 (53). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceSolar Pro 3Solar Pro 3 $0.25 · GLM-4.6V-Flash $0.261 · Grok 4 Fast Reasoning $0.275 per 1M tokens (3:1 blend)
- Longest contextGrok 4 Fast ReasoningGrok 4 Fast Reasoning 2,000,000 · Solar Pro 3 131,072 · GLM-4.6V-Flash 128,000 tokens
- Widest inputsGrok 4 Fast ReasoningGrok 4 Fast Reasoning: Text, Images, Audio, Video · Solar Pro 3: Text · GLM-4.6V-Flash: Text, Images, Video
- Self-hostingGLM-4.6V-FlashPublishes downloadable weights
| Measure | Weight | Grok 4 Fast Reasoning | Solar Pro 3 | GLM-4.6V-Flash |
|---|---|---|---|---|
| Price | 50% | 73 | 75 | 74 |
| Inputs & features | 30% | 80 | 35 | 70 |
| Context window | 20% | 72 | 25 | 24 |
| Overall | 100% | 75/100 | 53/100 | 63/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Grok 4 Fast ReasoningxAI | Solar Pro 3Upstage | GLM-4.6V-FlashZ.ai (Zhipu) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.20 | $0.25 | $0.161 (best) |
| Output | $0.50 | $0.25 (best) | $0.559 |
| Cached input | — | — | — |
| Blended (3:1) | $0.275 | $0.25 (best) | $0.261 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 4 providers | Official Upstage API | Median of 2 providers |
| Limits | |||
| Context window | 2,000,000 tokens (best) | 131,072 tokens | 128,000 tokens |
| Max output | 2,000,000 tokens (best) | 8,192 tokens | 32,768 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | No | Yes |
| PDFs | No | No | No |
| Audio | Yes | No | No |
| Video | Yes | No | Yes |
| Reasoning | Yes | Yeslow · medium · high | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | No | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Open |
| API model ID | — | solar-pro3 | glm-4.6v-flash |
| API providers | 5 | 4 | 6 (best) |
| Released | Dec 18, 2025 | Jan 26, 2026 | Dec 8, 2025 |
| Knowledge cutoff | — | Jul 2025 | — |
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 Fast Reasoning$3.00
- Solar Pro 3$3.00
- GLM-4.6V-Flash$2.73
Which should you choose?
Which is better: Grok 4 Fast Reasoning, Solar Pro 3 or GLM-4.6V-Flash?
Grok 4 Fast Reasoning is the better all-round choice, scoring 75/100 against GLM-4.6V-Flash (63) and Solar Pro 3 (53). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Grok 4 Fast Reasoning, Solar Pro 3 or GLM-4.6V-Flash?
Solar Pro 3 is cheaper at $0.25 input / $0.25 output per million tokens (official Upstage API price). GLM-4.6V-Flash costs $0.161 input / $0.559 output per million tokens (median across 2 API providers; free on Z.AI); Grok 4 Fast Reasoning costs $0.20 input / $0.50 output per million tokens (median across 4 API providers). At a typical mix of three input tokens to one output token, that is $0.25 per million tokens for Solar Pro 3 versus $0.261 for GLM-4.6V-Flash (1× as much) and $0.275 for Grok 4 Fast Reasoning (1.1× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Grok 4 Fast Reasoning has not been scored yet, Solar Pro 3 has not been scored yet and GLM-4.6V-Flash has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4 Fast Reasoning, Solar Pro 3 and GLM-4.6V-Flash yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Grok 4 Fast Reasoning has the largest context window at 2,000,000 tokens, against 131,072 for Solar Pro 3 and 128,000 for GLM-4.6V-Flash. Maximum output per response: Grok 4 Fast Reasoning up to 2,000,000, Solar Pro 3 up to 8,192, GLM-4.6V-Flash up to 32,768 tokens.
Which can read images, PDFs, audio or video?
Grok 4 Fast Reasoning accepts text, images, audio and video; Solar Pro 3 accepts text; GLM-4.6V-Flash accepts text, images and video. Grok 4 Fast Reasoning handles the widest range of inputs.
Are any of these open source?
GLM-4.6V-Flash publishes its weights and can be self-hosted; Grok 4 Fast Reasoning and Solar Pro 3 is proprietary.
Which is newer?
Solar Pro 3 is the newest, released Jan 26, 2026. Grok 4 Fast Reasoning came out Dec 18, 2025; GLM-4.6V-Flash came out Dec 8, 2025. Knowledge cutoff: Solar Pro 3 Jul 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.
