LLM Chat Format Converter

Convert conversations between OpenAI, Anthropic, plain text, and JSONL fine-tuning formats. Runs entirely in your browser.

Source format

→

Target format

Load example:

Input (OpenAI messages[])

4 message(s) parsed · system prompt detected

Output (Anthropic Messages API)

{
  "system": "You are a helpful assistant.",
  "messages": [
    {
      "role": "user",
      "content": "What is the capital of France?"
    },
    {
      "role": "assistant",
      "content": "The capital of France is Paris."
    },
    {
      "role": "user",
      "content": "What about Germany?"
    },
    {
      "role": "assistant",
      "content": "The capital of Germany is Berlin."
    }
  ]
}