Grok 4 Fast Reasoning vs Grok 4 Fast Non Reasoning
Grok 4 Fast Reasoning comes out ahead, 75 to 72 on our weighted score.
- Our pick
xAIGrok 4 Fast Reasoning
75/100- ECI—
- Price$0.20 / $0.50
- Context2M
- xAI
Grok 4 Fast Non Reasoning
72/100- ECI—
- Price$0.20 / $0.50
- Context2M
Add a model
Make it a three-way comparison.
Grok 4 Fast Reasoning is our pick
Grok 4 Fast Reasoning is the better all-round choice, scoring 75/100 against Grok 4 Fast Non Reasoning (72). It leads on inputs & features. 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 priceSame priceGrok 4 Fast Reasoning $0.275 · Grok 4 Fast Non Reasoning $0.275 per 1M tokens (3:1 blend)
- Longest contextAbout the sameGrok 4 Fast Reasoning 2,000,000 · Grok 4 Fast Non Reasoning 2,000,000 tokens
- Widest inputsSame inputsGrok 4 Fast Reasoning: Text, Images, Audio, Video · Grok 4 Fast Non Reasoning: Text, Images, Audio, Video
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Grok 4 Fast Reasoning | Grok 4 Fast Non Reasoning |
|---|---|---|---|
| Price | 50% | 73 | 73 |
| Inputs & features | 30% | 80 | 70 |
| Context window | 20% | 72 | 72 |
| Overall | 100% | 75/100 | 72/100 |
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 | Grok 4 Fast Non ReasoningxAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.20 | $0.20 |
| Output | $0.50 | $0.50 |
| Cached input | — | — |
| Blended (3:1) | $0.275 | $0.275 |
| Long-context rate | Same rate | Same rate |
| Price source | Median of 4 providers | Median of 7 providers |
| Limits | ||
| Context window | 2,000,000 tokens | 2,000,000 tokens |
| Max output | 2,000,000 tokens | 2,000,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | Yes | Yes |
| Video | Yes | Yes |
| Reasoning | Yes | No |
| Tool calling | Yes | Yes |
| Structured output | No | No |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | — | — |
| API providers | 5 | 8 (best) |
| Released | Dec 18, 2025 | Dec 18, 2025 |
| Knowledge cutoff | — | — |
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
- Grok 4 Fast Non Reasoning$3.00
Which should you choose?
Which is better: Grok 4 Fast Reasoning or Grok 4 Fast Non Reasoning?
Grok 4 Fast Reasoning is the better all-round choice, scoring 75/100 against Grok 4 Fast Non Reasoning (72). It leads on inputs & features. 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 or Grok 4 Fast Non Reasoning?
Grok 4 Fast Reasoning and Grok 4 Fast Non Reasoning cost the same: $0.20 input / $0.50 output per million tokens.
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Grok 4 Fast Reasoning has not been scored yet and Grok 4 Fast Non Reasoning has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4 Fast Reasoning and Grok 4 Fast Non Reasoning yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Grok 4 Fast Reasoning and Grok 4 Fast Non Reasoning share the same 2,000,000-token context window. Maximum output per response: Grok 4 Fast Reasoning up to 2,000,000, Grok 4 Fast Non Reasoning up to 2,000,000 tokens.
Which can read images, PDFs, audio or video?
Grok 4 Fast Reasoning accepts text, images, audio and video; Grok 4 Fast Non Reasoning accepts text, images, audio and video. They handle the same number of input types.
Are any of these open source?
No. Grok 4 Fast Reasoning and Grok 4 Fast Non Reasoning are proprietary and only available through APIs and apps.
Which is newer?
Grok 4 Fast Reasoning is the newest, released Dec 18, 2025. Grok 4 Fast Non Reasoning came out Dec 18, 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.
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