Grok 4.5 API

xAI's large language model for text generation and advanced reasoning

Modalities
TextText
In / Out price
$2/$6per 1M
Context window
500K tokens
Released
Jul 8, 2026

Grok 4.5 overview

The pelican test: one prompt, every text model, unedited SVG output from Nov 3, 2026.

SVG of a pelican riding a bicycle, written by Grok 4.5 through AI/ML API

Grok 4.5 by xAI

Grok 4.5 is a chat and code model from xAI for text and file inputs, with reasoning, function calling and streaming for multi-step workflows.

Grok 4.5 specs

Model ID
x-ai/grok-4-5
Developer
xAI
Context window
500,000 tokens
Input
Text
Output
Text
API
OpenAI-compatible, base URL https://api.aimlapi.com/v1

Use cases

Grok 4.5 is documented as suited to coding, engineering, design, and professional workflows. It is also described as built for coding, agentic tasks, and knowledge work.

It is suited to everyday assistant use such as explaining unfamiliar topics, weighing big purchases, planning trips, and digging into topics of interest. The same source says it can also take tasks from start to finish, including building spreadsheets, turning outlines into slides and diagrams, drafting prose, and extracting key points from long PDFs.

It is suited to software engineering and office-document work, including building complex Excel models with web research and multi-sheet formulas, and creating PowerPoint and Word content. The model is also described as capable of using native PowerPoint shapes for diagrams and writing clear prose in Word.

It is suited to developer workflows that involve external tools and systems, with documentation stating it can connect to external tools and systems and return responses in specific, organized formats.

Capabilities

  • Reasoning
  • Function calling
  • Streaming

Grok 4.5 benchmarks by Artificial Analysis

See how Grok 4.5 compares in generation speed and latency. Data retrieved Nov 3, 2026.

Speed

Output tokens / second

Benchmark results

Compare 8 models available on AI/ML API across 5 independent benchmarks.

Humanity's Last Exam

Expert-written questions across academic subjects.

Grok 4.5 API pricing

Grok 4.5 pricing in US dollars
UsagePriceUnit
Input$21M tokens
Output$61M tokens
Cached input$0.31M tokens

Prices from the AI/ML API price list, checked on Nov 4, 2026.

Grok 4.5 vs other models: token prices

AI/ML API input and output rates for 5 models, per million tokens.

AI/ML API model prices in USD per million tokens
ModelInputOutput
Grok 4.5$2$6
Grok Build 0.1$1$2
Grok 4.3$1.25$2.5
Grok 4.7$2$6
Grok 4.6$2$6

How to use the Grok 4.5 API

View docs

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key
export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "x-ai/grok-4-5",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

Related articles

All posts

Grok 4.5 FAQ

What is the context window of Grok 4.5?

Grok 4.5 has a 500,000 tokens context window.

What inputs and outputs does Grok 4.5 support?

Grok 4.5 takes text, file in as input and returns text out.

What is the model ID for Grok 4.5?

Use x-ai/grok-4-5 as the model id.

When was Grok 4.5 released?

Grok 4.5 became available on July 8, 2026.

How much does Grok 4.5 cost?

Grok 4.5 costs $2 input and $6 output per 1M tokens on AI/ML API, billed as you go with no subscription.

Does Grok 4.5 support streaming?

Yes, Grok 4.5 can stream responses as they are generated.

Who created Grok 4.5?

Grok 4.5 was built by xAI .

Start building with Grok 4.5

Grok 4.5 API

x-ai/grok-4-5

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key
export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "x-ai/grok-4-5",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'