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xAI: Grok 4 Fast
Server-rendered model summary page for indexing/share previews. Use the interactive explorer for full filtering and comparison.
Match confidence: UnmatchedSource type: openrouter_only
Context window
2M
Arena overall rank
—
Input price
$0.000 / 1M
Output price
$0.000 / 1M
Identifiers & provenance
- Primary ID
- x-ai/grok-4-fast
- OpenRouter ID
- x-ai/grok-4-fast
- Canonical slug
- x-ai/grok-4-fast
Source semantics
- Arena rank is a human-preference leaderboard signal, not a universal truth metric.
- OpenRouter usage/popularity reflects adoption/traffic, not benchmark quality.
- Pricing fields may differ by provider and can include extra modes beyond prompt/completion.
Read more on Methodology & data sources.
Description
Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast). Reasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)
Raw fields snapshot
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"created": 1758240090,
"canonical_slug": "x-ai/grok-4-fast",
"hugging_face_id": "",
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"modality": "text+image->text",
"tokenizer": "Grok",
"instruct_type": null,
"supported_parameters": [
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"seed",
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"default_parameters": {
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"PPM": {
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"openrouter_raw": {
"id": "x-ai/grok-4-fast",
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"hugging_face_id": "",
"name": "xAI: Grok 4 Fast",
"created": 1758240090,
"description": "Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast).\n\nReasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)",
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}