Claude API

How do you send images to the Claude API?

Last verified: July 2026 · 2 min read
QUICK ANSWER

To send an image to the Claude API, include an image content block in your messages array, passing the base64-encoded file string and declaring the correct media type.

JSON Payload Image Request

{
  "model": "claude-3-5-sonnet-20241022",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": [
        {
          "type": "image",
          "source": {
            "type": "base64",
            "media_type": "image/jpeg",
            "data": "/9j/4AAQSkZJRgABAQEASABIAAD..."
          }
        },
        {
          "type": "text",
          "text": "What is in this picture?"
        }
      ]
    }
  ]
}
Verified against: Anthropic API Vision Spec

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