📦 convt — Universal File Converter CLI

convt is a fast, modern, lightweight CLI tool for converting structured data files
(JSON, CSV, TSV, XML, BSON, YAML, TOML, XLSX) into any other supported format.

Perfect for quick data transformations, scripting, pipelines, ETL workflows, developer utilities, and everyday CLI usage.

🚀 Features

• Convert between 9+ file formats
• Supports partial conversions (first, last, random, range)
• Extract a single column from tabular data
• Zero dependencies for most formats
• Built with modern Node.js (ESM)
• Works in pipelines (stdin → stdout)
• Fast and safe structure validation

📥 Installation

npm install -g convt
pnpm add -g convt
yarn global add convt

🧠 Supported Formats

| Format | Read | Write | | ------ | ---- | ----- | | JSON | ✔️ | ✔️ | | CSV | ✔️ | ✔️ | | TSV | ✔️ | ✔️ | | XML | ✔️ | ✔️ | | YAML | ✔️ | ✔️ | | TOML | ✔️ | ✔️ | | BSON | ✔️ | ✔️ | | XLSX | ✔️ | ✔️ |

🔄 Convert Command

Usage

convt <file> [options]

Options

| Option | Description | | ------------------- | ----------------------------------------------------------- | | --target | Target format (csv, json, xlsx, yaml, xml, bson, toml, tsv) | | --output | Output file path | | --first | Convert the first N rows | | --last | Convert the last N rows | | --random | Convert random N rows | | --range | Convert rows in a range |

Examples

convt data.json --target csv --output data.csv
convt data.csv --target json
convt data.csv --first 20 --target json
convt data.csv --range 50-100 --target tsv
convt logs.csv --random 10 --target json

🔍 Extract Command

convt extract <file> [options]

Options

| Option | Description | | ----------------- | ------------------ | | --column | Column to extract | | --key | Custom key name | | --output | Output file path | | --headless | Output only values | | --target | Output format |

Extract Examples

convt extract users.csv --column email --target json --output emails.json
convt extract users.csv --column id --headless --target txt
convt extract data.csv --column country --target yaml

📤 STDIN Support

cat data.csv | convt --target json
curl https://example.com/data.csv | convt --target xlsx --output out.xlsx

🧪 Exit Codes

| Code | Meaning | | ---- | ------------------ | | 0 | Success | | 1 | File not found | | 2 | Unsupported format | | 3 | Parse error | | 4 | Write error | | 5 | Invalid arguments |

🏗 Roadmap

• Streamed XLSX writer
• JSON → TOON format support
• Custom delimiter support
• Config file support
• Batch conversion
• Web UI wrapper

🤝 Contributing

PRs welcome!

📄 License

MIT License © 2025