Introducing Grok 4.5

Today, we're launching Grok 4.5, SpaceXAI's smartest model built to excel at coding, agentic tasks, and knowledge work. It's our strongest model ever and was trained alongside Cursor.

Real-world engineering excellence

Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks. The model is equally adept at office work, scoring #1 on Harvey's Legal Agent Benchmark.

Training Grok 4.5

Grok 4.5 was trained across tens of thousands of NVIDIA GB300 GPUs, with training and stability techniques designed for large-scale runs. Beyond raw token volume, we invested heavily in data filtering and curation: deduplication, quality scoring, and domain-focused selection so that the data mixture stayed high-coverage and high-signal.

We scaled reinforcement learning with a strong focus on per-token intelligence. Our RL training covers hundreds of thousands of tasks, centered on multi-step software engineering and other technical work, with automated and model-based grading. Our stack is built for highly asynchronous training, so agentic rollouts can run for many hours while learning continues across tens of thousands of GPUs. The result is more intelligent and efficient reasoning on real engineering and agentic tasks.

Faster than flash models

Grok 4.5 is served at fast-model speeds of 80 TPS. Combined with twice greater token efficiency than the latest leading models at the same tasks, the model delivers intelligent results to you more quickly and at far lower costs.

Excels at Office work

Grok 4.5 is now the default model in Grok Build. In addition to its coding proficiency, Grok Build is capable of building complex Excel models that involve research from the web, multi-sheet formula use, and even leaves stickies or notes behind for future reference.

In PowerPoint and Word, Grok 4.5 is similarly meticulous. The model is capable of using native PowerPoint shapes to build complex diagrams, designing intuitive slide content, and writing clear prose in Word.

Learn more about our plugins for Word, PowerPoint, and Excel.

Pricing

Grok 4.5 is delivered at an incredibly competitive cost compared to other leading models. Grok 4.5 is priced at $2 per million input tokens and $6 per million output tokens. The model also achieves roughly 2x the token efficiency of comparable leading models, solving tasks in under half the number of steps. Overall, Grok 4.5 delivers the highest intelligence per unit of time and cost.

Getting started

Grok 4.5 is available today in Grok Build, in Cursor on all plans, and from the SpaceXAI console. Simply grab an API key and get started in a few lines of code:

curl -s https://api.x.ai/v1/responses \
  -H "Authorization: Bearer $XAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4.5",
    "input": "Find and fix the bug, then explain it: function median(a){a.sort();return a[a.length/2]}"
  }'

Note: Grok 4.5 is not yet available in the EU in any SpaceXAI products or the API console. EU availability is expected in mid-July.