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xAI

Grok 4.5

Released Jul 9, 2026 · knowledge cutoff 2026-02

Status
Superseded
Location
United States
Type
LLM
Modality
Multimodal
Context window
500K
Max output
—
Speed (high effort)
48 tok/s · 13s to first answer token
Price ($/MTok in / out)
$2 / $6
Cost per task (high effort)
$0.35
Open weights
No
Benchmarks6 of 10 reported

GPQA Diamond

93.1%

SWE-bench Pro

64.7%

Terminal-Bench 2.1

83.3%

Humanity's Last Exam

40.3%

LMArena Elo

1468

ARC-AGI-2

52.6%

MMLU-Proretired

—

SWE-bench Verified

—

AIME (latest)retired

—

GDPval-AA v2

—
Strengths & weaknesses

Strengths

  • Finishes tasks in fewer steps, so agent runs are cheap in practice rather than just per token
  • Fast, decisive answers with very little hedging
  • Trained partly on real developer sessions, which shows in routine coding-agent work

Weaknesses

  • Hallucinates far more than the model before it — confident, wrong, and in need of grounding for factual work
  • Drops off on the hardest and most novel problems, where 'close enough' isn't
  • Less public detail on safety and governance than rival labs published

Announced July 8, public release July 9, 2026. GPQA Diamond 93.1%, HLE 40.3%, ARC-AGI-2 52.6%, and LMArena Elo 1468 are third-party (BenchLM/arena.ai) — xAI did not publish these itself, leading with SWE-bench Pro (64.7%) and SWE Marathon (29.0%) instead, so sweBench (Verified) is left null. Max output tokens unconfirmed — xAI's own model page documents the 500K context window and tiered pricing but no output cap; a ~30K figure appears only on secondary blogs, so left null. Knowledge cutoff confirmed as February 1, 2026 in xAI's official docs (docs.x.ai). Terminal-Bench 2.1 83.3% is third-party (BenchLM's TB 2.1 board, 2026-08-31, which layer3labs and DataCamp attribute to Artificial Analysis' high-effort run); Meta's Muse Spark 1.2 launch chart separately shows 81.6% for Grok 4.5 inside Grok Build, a different harness.

For developers

API model strings

  • xaigrok-4.5

Licence

Proprietary — weights not released

Retirement

No retirement announced

Lineage

No recorded predecessor

News