What is OpenAI fine-tuning format?

OpenAI requires training data as JSONL where each line has a "messages" array: [{role:"system",content:"..."},{role:"user",content:"..."},{role:"assistant",content:"..."}]. This tool converts your CSV to that format.

What CSV column names does it expect?

For chat format: use columns named "system", "user", "assistant". For legacy format: use "prompt" and "completion". The tool auto-detects which format your CSV uses.

Yes. Completely free. No OpenAI account needed for the conversion — that's only needed when you upload to OpenAI.

Does my data get sent to OpenAI?

No. This tool only formats your data. You need to upload the resulting .jsonl file to OpenAI yourself via their API or dashboard.

What models can I fine-tune with this data?

The messages format works with gpt-4o-mini, gpt-3.5-turbo, and other chat models that OpenAI supports for fine-tuning.

✓ Auto-detects format✓ Chat & legacy modes✓ Free forever

Free CSV → OpenAI Format Converter

Convert your training CSV to OpenAI fine-tuning JSONL. Supports chat and legacy format. Free. Used by AI developers across India.

Sample:

CSV format: Use columns system, user, assistant for chat format, or prompt, completion for legacy. The tool auto-detects which you use.

CSV Input

OpenAI JSONL Output

Frequently asked questions

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