Convert training data between JSONL, CSV, and chat completion formats for fine-tuning OpenAI, Anthropic, and other LLMs. Validate and preview your dataset.
Drop or click to upload a file (.jsonl, .csv, .json, .txt)
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Input Data
Output
Conversation Preview (first example)
How to Use the Training Data Formatter
Paste or upload your training data in any supported format.
Select input and output formats (or use auto-detect).
Click Convert to transform the data.
Validate to check for errors before uploading to OpenAI or Anthropic.
Download the converted file in the correct format.