Grok 4.5 is xAI's flagship reasoning model, released on July 8, 2026, and built for developers, AI agents, and knowledge workers rather than casual chat. Co-developed with the Cursor coding editor and trained on tens of thousands of Nvidia GB300 GPUs, it is positioned as an 'Opus-class' model that is faster, more token-efficient, and cheaper than rivals such as Anthropic's Opus 4.8 and OpenAI's GPT-5.5.
Core Features
- 1.5-trillion-parameter V9 mixture-of-experts architecture with a 500,000-token context window and vision input (jpg/png up to 20 MiB).
- Agentic coding strength: scored 83.3% on Terminal-Bench 2.1 and 64.7% on SWE-Bench Pro, beating GPT-5.5 on the latter benchmark.
- Token efficiency: resolves SWE-Bench Pro tasks with about 15,954 output tokens versus 67,020 for Opus 4.8, roughly 4.2x fewer.
- Configurable reasoning budget and fast serving at roughly 80 to 119 tokens per second via Grok Build and the xAI API console.
Best For
- Solo developers and startups running high-volume coding and agentic workflows on a tight budget.
- Teams already on Cursor, where Grok 4.5 is bundled into every subscription plan.
- Cost-sensitive production deployments that need frontier-tier quality without per-token blowups.
Pricing
Grok 4.5 is billed at $2 per million input tokens and $6 per million output tokens through the xAI developer console, with no subscription required. Cursor users get it inside their existing plan, and a free tier exists on xAI's consumer app. Compare it with other frontier models in our aifreetool.site/tool-category/ai-engine-model/ listings.
Our Take
Grok 4.5 is the best-value frontier model of mid-2026: not the strongest on every benchmark, but its token efficiency makes real coding work far cheaper than Opus 4.8. The trade-off is that it lags on the hardest long-horizon SWE-Bench Pro tasks.
