CSV to Parquet Converter
Convert CSV files to Apache Parquet format instantly in your browser. Automatic type inference, Snappy compression, no uploads required.
How to Use CSV to Parquet Converter
How to Use CSV to Parquet Converter
What is Apache Parquet?
Apache Parquet is a columnar storage format widely used in data engineering and analytics. Compared to CSV, Parquet offers:
- Smaller file sizes — typically 2–10x smaller due to columnar encoding and compression
- Faster queries — column pruning means only relevant columns are read
- Type safety — explicit schema with typed columns
- Wide ecosystem support — Spark, Flink, BigQuery, Redshift, DuckDB, Pandas, and more
Step 1: Upload Your CSV File
Click the upload area or drag and drop your .csv file. The first row must contain column headers. Maximum file size: 50MB.
Step 2: Convert
Click "Convert to Parquet". The tool:
- Parses the CSV (handles quoted values, commas in fields)
- Infers the column type for each column (BOOLEAN, INT32, INT64, DOUBLE, or STRING)
- Writes a Parquet file with Snappy compression
Step 3: Download
Click "Download Parquet" to save the .parquet file. The output uses the same base name as the input.
Type Inference
The converter automatically detects column types:
true/falsevalues → BOOLEAN- Whole numbers fitting 32-bit range → INT32
- Whole numbers outside 32-bit range → INT64
- Decimal numbers → DOUBLE
- Everything else → STRING
Tips
- Ensure your CSV has a header row as the first line
- Empty cells in numeric columns are stored as null
- For large datasets (10MB+), processing may take a few seconds
- The output Parquet file uses Snappy compression by default
- All processing is offline after page load — no internet required
Frequently Asked Questions
Most Viewed Tools
Screen Size Converter
Calculate screen width and height from diagonal size and aspect ratio. Convert between inches and centimeters for displays, TVs, and monitors with instant dimension calculations.
Use Tool →Reorder PDF Pages
Drag and drop to rearrange PDF pages in any order. Upload your PDF, preview all pages as thumbnails, drag pages to reorder them, and download the rearranged PDF. Fast, visual, and privacy-focused.
Use Tool →DPI Calculator
Calculate DPI (dots per inch), image dimensions, and print sizes. Convert between pixels and physical dimensions for printing and displays.
Use Tool →Paper Size Converter
Convert between international paper sizes (A4, Letter, Legal) with dimensions in mm, cm, and inches. Compare ISO A/B series and North American paper standards.
Use Tool →Fuel Consumption Converter
Convert between MPG (miles per gallon), L/100km (liters per 100 kilometers), and other fuel efficiency units. Compare car fuel economy across different measurement systems.
Use Tool →CSV Splitter
Split large CSV files into smaller files by number of rows. Process large datasets in manageable chunks instantly.
Use Tool →Product Schema Generator
Generate JSON-LD Product schema markup for SEO. Add product details like name, price, brand, rating, and availability to create structured data for rich search results.
Use Tool →Large Text File Viewer
View and search large text files up to 200MB in your browser. Features virtual scrolling, line numbers, search functionality, and file statistics. Perfect for log files, CSV, JSON, and code files.
Use Tool →Related Development Tools
QR Code Generator
FeaturedCreate custom QR codes for URLs, text, and contact info
Use Tool →XML to TOON Converter
Convert XML to TOON (Token Oriented Object Notation) and reduce LLM token usage. XML is the most verbose format — savings can exceed 50%. Free, browser-based.
Use Tool →Ruby Formatter
Format and clean up Ruby code instantly in your browser. Fix indentation, align end blocks, and normalize string quotes — no server required.
Use Tool →Parquet to CSV Converter
Convert Apache Parquet files to CSV format instantly in your browser. No uploads, no server — all processing is 100% client-side.
Use Tool →CSS to SCSS Converter
Convert plain CSS to SCSS/Sass instantly. Automatically nests child selectors under their parents, extracts repeated hex colors as $variables, and preserves @media blocks — no server required.
Use Tool →Kotlin Formatter
Format Kotlin code instantly in your browser. Fix indentation, enforce opening-brace-on-same-line style, and add trailing commas to function parameters and class bodies — no server required.
Use Tool →YAML to JSON Converter
Convert YAML data to JSON format instantly. Supports nested objects, arrays, and multi-level structures. Output as pretty-printed or minified JSON. 100% client-side and free.
Use Tool →Swift Formatter
Format Swift code instantly in your browser. Fix indentation, enforce opening-brace-on-same-line style, and normalize spacing around operators — no server required.
Use Tool →Share Your Feedback
Help us improve this tool by sharing your experience