Grok 4.1 Fast (Reasoning)
Latest GrokxAI's fast agentic tool-calling model with a 2M context window and built-in reasoning
- Context window
- 2M tokens in · 30K out
- Since the last one
- 61 days after Grok 4 Fast
Since Grok 4 Fast
3 releases in the Grok line.
Released61 days later
BENCHMARKS
Not in the Epoch Capabilities Index. Epoch benchmarks what it can run, so this is a gap in coverage, not a poor result.
xAI's past year
19 release days in the past year, about one every 19 days. The next is expected around Nov 10, 2026. Forecasts ↗
NovDecJanFebMarAprMayJunJulAugSepOctNov
Specifications
RELEASE DATENov 19, 2025
WEIGHTSClosed weights
CONTEXT WINDOW2M
MAX OUTPUT30K
REASONINGNot listed
TOOL CALLINGNot listed
INPUTStext, image/jpeg, image/png
OUTPUTStext
Specifications and prices from Models.dev; availability and limits may differ by provider. Benchmarks from Epoch AI (CC BY 4.0), LiveBench and the other sources named above.