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x-ai/grok-4-fast
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Grok 4 Fast
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)
9/19/2025
2,000,000 tokens
#92 Text (Japanese)
Specifications
Modalities
Input
text
image
Output
text
Supported Parameters
include_reasoning
logprobs
max_tokens
reasoning
response_format
seed
structured_outputs
temperature
tool_choice
tools
top_logprobs
top_p
Max Output Tokens
30,000Leaderboard
Text
๐OverallELO: 1,404
#129๐ฏ๐ตJapaneseELO: 1,367
#92๐จ๐ณChineseELO: 1,442
#121๐ฐ๐ทKoreanELO: 1,347
#112๐ฌ๐งEnglishELO: 1,414
#133frenchELO: 1,442
#94germanELO: 1,386
#114spanishELO: 1,413
#95russianELO: 1,398
#129๐ปCodingELO: 1,437
#143๐งฎMathELO: 1,411
#114โ๏ธCreative WritingELO: 1,381
#120๐Instruction FollowingELO: 1,388
#136๐ถ๏ธHard PromptsELO: 1,413
#148๐ฌMulti-TurnELO: 1,406
#127Code
๐OverallELO: 1,160
#107