xAI model product
Grok 4.1 Fast Reasoning
Bringing the next generation of tool-calling agents to the xAI API.
Updated Aug 17, 2026. Default version: Grok-4.1 Fast Reasoning
LLMBoard Text Score53.9Grok-4.1 Fast Reasoning
Coverage100%17 benchmark families
Context window2MTokens
Official input priceN/AOfficial price unavailable
Grok 4.1 Fast Reasoning Capability Profile
This profile uses the model's current scored version. Arena ratings and prices are shown separately.
Grok 4.1 Fast Reasoning Benchmark Results
Benchmark scores for Grok-4.1 Fast Reasoning.
No benchmark results
No benchmark result is linked to the scored version.
Grok 4.1 Fast Reasoning Arena Results
Preference and agent-evaluation results for the default version.
Sort by
Arena | Category | Rank | Rating / score | Votes | Observations | Result date |
|---|
| Arenavision | Categoryoverall | Rank72 | Rating / score1199.9 | Votes12,462 | ObservationsN/A | Result date |
| Arenavision style control | Categoryoverall | Rank75 | Rating / score1195.2 | Votes12,462 | ObservationsN/A | Result date |
| Arenatext style control | Categoryoverall | Rank91 | Rating / score1430.7 | Votes56,811 | ObservationsN/A | Result date |
| Arenawebdev | Categoryoverall | Rank104 | Rating / score1240.0 | Votes5,331 | ObservationsN/A | Result date |
| Arenatext factuality | Categoryoverall | Rank121 | Rating / score1413.0 | Votes55,884 | ObservationsN/A | Result date |
| Arenatext | Categoryoverall | Rank122 | Rating / score1408.2 | Votes56,811 | ObservationsN/A | Result date |
Grok 4.1 Fast Reasoning Pricing
Official vendor API pricing appears first, followed by individual provider offers.
- Official API
- N/A
- Official provider
- N/A
- Lowest third-party
- From $0.18 input, $0.45 output per 1M via Jiekou.AI
- Tracked offerings
- 8
Sort by
Provider | Provider model ID | Region | Input / 1M | Output / 1M | Context | Updated |
|---|
| ProviderJiekou.AI | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.18 | Output / 1M$0.45 | Context2M | Updated |
| ProviderHelicone | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context2M | Updated |
| Provider302.AI | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context2M | Updated |
| ProviderAzure | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context128K | Updated |
| ProviderFrogBot | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context2M | Updated |
| ProviderVercel AI Gateway | Provider model IDxai/grok-4.1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context1M | Updated |
| ProviderLLM Gateway | Provider model IDgrok-4-1-fast-reasoning | Regionglobal | Input / 1M$0.20 | Output / 1M$0.50 | Context2M | Updated |
Official prices use only the vendor's configured official Provider and positive standard USD PAYG rates. Third-party offers remain explicitly labeled.
Grok 4.1 Fast Reasoning Runtime Performance
Provider-specific output speed and catalog latency for Grok-4.1 Fast Reasoning. Runtime does not affect the capability score.
Sort by
Provider | Output Speed | Catalog Latency | Max Input | Max Output | Updated |
|---|
| ProviderxAI | Output Speed90 tok/s | Catalog LatencyN/A | Max Input2M | Max Output30K | Updated |
Output Speed is generated output tokens received per second. Catalog latency is reported separately from observed provider TTFT.
Grok 4.1 Fast Reasoning Specifications
Technical details for the model's default version.
- Version
- Grok-4.1 Fast Reasoning
- Released
- Nov 17, 2025
- Knowledge cutoff
- Unknown
- Parameters
- N/A
- Context window
- 2M
- Max output
- 30K
- Inputs
- image, text
- Outputs
- text
- Open weights
- No
- License
- Proprietary
Grok 4.1 Fast Reasoning Versions
Available versions of this model. The score column identifies the version used in the overall ranking.
Sort by
Version | Released | LLMBoard | Parameters | Context | Max output | Open weights | License |
|---|
| VersionGrok-4.1 Fast Reasoning | Released | LLMBoard53.9 | ParametersN/A | Context2M | Max output30K | Open weightsNo | LicenseProprietary |
Grok 4.1 Fast Reasoning vs nearby models
Open a comparison with the three ranked models immediately above and below this model.
Models similar to Grok 4.1 Fast Reasoning
Recommendations prioritize the same model type and family, then the closest LLMBoard score.
XA
Grok 4 Fast Reasoning
xAI
XA
Grok 4.3
xAI
XA
Grok 4 Fast
xAI
XA
Grok 4
xAI
XA
Grok 3
xAI
XA
Grok 3 Mini
xAI
What is Grok 4.1 Fast Reasoning?
Key information about Grok 4.1 Fast Reasoning and its available data.
Bringing the next generation of tool-calling agents to the xAI API. 1 Fast Reasoning is a high-speed variant optimized for faster inference while maintaining strong reasoning capabilities through thinking tokens.
Data as of 2026-08-17.
FAQ
Common questions about Grok 4.1 Fast Reasoning.
When was Grok 4.1 Fast Reasoning released?
Grok 4.1 Fast Reasoning's default version was released on Nov 17, 2025.
How much does Grok 4.1 Fast Reasoning cost?
No official standard PAYG price is currently available for Grok 4.1 Fast Reasoning. The lowest tracked third-party offer starts at $0.18 input and $0.45 output via Jiekou.AI.
Who created Grok 4.1 Fast Reasoning?
Grok 4.1 Fast Reasoning was created by xAI.
What is the context window for Grok 4.1 Fast Reasoning?
The default version has a 2M token context window.
Is Grok 4.1 Fast Reasoning open weight?
No. The default version is not marked as having publicly available weights.
How many API providers offer Grok 4.1 Fast Reasoning?
8 provider offerings are linked to the default version.
What models should I compare Grok 4.1 Fast Reasoning with?
Nearby ranked alternatives include GPT-5, Step 3.5 Flash, o3.