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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
#91 Text (french)
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

30,000
Leaderboard
Text
๐Ÿ†OverallELO: 1,404
#124
๐Ÿ‡ฏ๐Ÿ‡ตJapaneseELO: 1,366
#92
๐Ÿ‡จ๐Ÿ‡ณChineseELO: 1,442
#117
๐Ÿ‡ฐ๐Ÿ‡ทKoreanELO: 1,348
#110
๐Ÿ‡ฌ๐Ÿ‡งEnglishELO: 1,414
#128
frenchELO: 1,442
#91
germanELO: 1,386
#112
spanishELO: 1,413
#92
russianELO: 1,398
#124
๐Ÿ’ปCodingELO: 1,437
#139
๐ŸงฎMathELO: 1,412
#109
โœ๏ธCreative WritingELO: 1,382
#114
๐Ÿ“Instruction FollowingELO: 1,388
#131
๐ŸŒถ๏ธHard PromptsELO: 1,413
#143
๐Ÿ’ฌMulti-TurnELO: 1,406
#122
Code
๐Ÿ†OverallELO: 1,151
#99