 Grok 4 Fast |  Sonar | |
|---|---|---|
Model Provider The organization behind this AI's development | XAI | Perplexity |
Input Context Window Maximum input tokens this model can process at once | 2M tokens | 127.1K tokens |
Output Token Limit Maximum output tokens this model can generate at once | 30K tokens | Not specified tokens |
Release Date When this model first became publicly available | September 19, 2025 1 month ago September 19th, 2025 | January 27, 2025 8 months ago January 27th, 2025 |
Grok 4 Fast | Sonar | |
|---|---|---|
Input Types Supported input formats | 📝Text🖼️Image | 📝Text🖼️Image |
Output Types Supported output formats | 📝Text | 📝Text |
Tokenizer Text encoding system | Grok | Other |
Key Features Advanced capabilities | ✓Function Calling✓Structured Output✓Reasoning ModeContent Moderation | Function CallingStructured OutputReasoning ModeContent Moderation |
| Grok 4 Fast | Sonar | |
|---|---|---|
Input Token Cost Cost per million input tokens | $0.20 per million tokens | $1.00 per million tokens |
Output Token Cost Cost per million outut tokens | $0.50 per million tokens | $1.00 per million tokens |
| Grok 4 Fast | Sonar | |
|---|---|---|
MMLU Measures knowledge across 57 subjects like law, math, history, and science | Benchmark not available. | Benchmark not available. |
MMMU Measures understanding of combined text and images across various domains | Benchmark not available. | Benchmark not available. |
HellaSwag Measures common sense reasoning by having models complete sentences about everyday situations | Benchmark not available. | Benchmark not available. |
Grok 4 Fast by XAI understands both text and images, can use external tools and APIs, offers advanced reasoning, generates structured data. It can handle standard conversations with its 2M token context window. Very affordable at $0.20/M input and $0.50/M output tokens. Released September 19th, 2025.Sonar by Perplexity understands both text and images. It can handle standard conversations with its 127.1K token context window. Reasonably priced at $1.00/M input and $1.00/M output tokens. Released January 27th, 2025.Compare your models with top performers across different categories
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