Grok 4.5 is so cheap compared to Fable 5 and GPT 5.5 that benchmark gaps may not matter much

AchievementBenchmarkJul 9, 2026

Artificial Analysis ranks Grok 4.5 fourth on its Intelligence Index, behind Fable 5, GPT-5.5, and Opus 4.8. The model gained 16 points over Grok 4.3, placing xAI near frontier performance. Grok 4.5 costs $0.31 per task, making it five times cheaper than Claude Sonnet 5. On coding tasks, it matches GPT-5.5 at 76 points while using significantly fewer tokens. However, its hallucination rate rose sharply to 54 percent.

Evidence

1source· awaiting independent confirmation

No score is assigned. Sources and their independence are shown in the citation chain below.

Citation chain · 1 source

01med

the-decoder.comBloghttps://the-decoder.com/grok-4-5-is-so-cheap-compared-to-fable-5-and-gpt-5-5-that-benchmark-gaps-may-not-matter-much/

PRIMARY

Canonical: https://the-decoder.com/grok-4-5-is-so-cheap-compared-to-fable-5-and-gpt-5-5-that-benchmark-gaps-may-not-matter-much/