Grok-1.5
xAI's Grok-1.5 is the successor to the open-weight Grok-1, emphasizing long-context understanding and substantially stronger math, code, and reasoning performance.
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Benchmarks: Reports 50.6% on the MATH benchmark, 90.0% on GSM8K, 74.1% on HumanEval, and 81.3% on MMLU - a large jump over Grok-1 and competitive with contemporary closed-source peers.
128K context window: Grok-1.5 can process up to 128K tokens, a 16x expansion over Grok-1, enabling longer documents and multi-turn sessions without external retrieval.
Long-context retrieval: On in-house needle-in-a-haystack evaluations the model demonstrates strong recall across its full 128K window, not just near the boundaries.
Availability: Rolled out first to early testers and existing Grok users on 𝕏, with broader release planned as the platform continues to iterate on reasoning and agentic features.