✓ 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

How to use CSV to OpenAI Format

Three steps. Instant results.

📋

Paste CSV Data

Ensure your CSV has columns like system, user, assistant or prompt, completion.

⚡

Click Convert

The tool detects the format and builds the JSONL required by OpenAI.

⬇️

Copy or Download

Download the .jsonl file ready for fine-tuning via the OpenAI API.

What output format does this tool create?

It outputs JSONL where each line contains a messages array for OpenAI fine-tuning.

Which CSV columns are supported?

Use system, user, assistant for chat format or prompt, completion for legacy. The tool auto-detects.

Is this converter free?

Yes. It is free with no limits. You only need an OpenAI account when you upload the file.

Does it send data to OpenAI?

No. Conversion is local in your browser. You upload the JSONL yourself.

Can I fine-tune chat models with this?

Yes. The messages format is required for chat model fine-tuning.

What if a row is missing required fields?

The tool shows an error so you can fix the CSV and try again.

How many training examples should I include?

More is better. Start with at least 10 high quality examples and iterate.