Parquet vs CSV vs Excel: Complete Format Comparison (2025)

Choosing the right data format makes a huge difference. Here's when to use each format for optimal performance.

Quick Format Guide

Format Best For File Size Speed Max Rows Compatibility
Excel (.xlsx) Formulas, formatting, business reports Medium Slow 1M max ✅ Universal
CSV (.csv) Simple data, universal compatibility Large Medium Unlimited ✅ Universal
Parquet (.parquet) Big data, fast queries, analytics Small Very fast Unlimited ⚠️ Data tools

The Winner for Big Data: Parquet

When you have 10M+ rows, need fast filtering/searching, repeated analysis on same data, or large files (multi-GB), Parquet is 10-100x faster and 80-90% smaller than CSV or Excel.

⭐

Parquet (.parquet) - Best for Big Data

File Size

80-90% smaller than CSV

Speed

10-100x faster queries

Max Rows

Unlimited (billions+)

Compatibility

Data tools (Diwadi, pandas, Spark)

Pros:

  • ✅ Columnar storage = 10-100x faster queries (especially column-specific operations)
  • ✅ 80-90% smaller than CSV (built-in compression, typically 5-10x)
  • ✅ Preserves schema (data types, column names)
  • ✅ Industry standard (Apache open-source)
  • ✅ Billions of rows (no practical limit)

When to Use Parquet:

  • • 10M+ rows
  • • Fast filtering/searching needed
  • • Large file sizes (multi-GB CSVs)
  • • Repeated analysis (load once, query many times)
  • • Data engineering workflows

Performance Example (100M rows):

CSV: File size: 20 GB | Open time: 5 minutes | Filter time: 3 minutes

Parquet: File size: 4 GB (80% smaller) | Open time: 10 seconds (30x faster) | Filter time: 2 seconds (90x faster)

CSV (.csv) - Universal Compatibility

File Size

Large (no compression)

Speed

Medium

Pros:

  • ✅ Universal compatibility (Excel, Sheets, pandas, SQL, etc.)
  • ✅ Human-readable (open in text editor)
  • ✅ Simple format (just comma-separated values)
  • ✅ Unlimited rows (no hard limit)
  • ✅ Easy to create/edit

Cons:

  • ❌ Large files (no compression)
  • ❌ Slow queries (must scan entire file)
  • ❌ No schema (all values are text)

When to Use CSV:

  • • Need universal compatibility
  • • Sharing with others (everyone can open CSV)
  • • Simple data (no nested structures)
  • • 1M-100M rows (if speed isn't critical)

Excel (.xlsx) - Business Reports

File Size

Medium (compressed XML)

Max Rows

1,048,576 (hard limit)

Pros:

  • ✅ Formulas (calculations, VLOOKUP, pivot tables)
  • ✅ Formatting (colors, fonts, borders)
  • ✅ Charts/graphs (visualizations)
  • ✅ Multiple sheets (organize data)
  • ✅ Universal in business

Cons:

  • ❌ 1M row limit (hard ceiling)
  • ❌ Slow performance (>100K rows = freeze/crash)
  • ❌ Not ideal for data processing

When to Use Excel:

  • • <1M rows
  • • Need formulas, formatting, charts
  • • Standard business reports
  • • Sharing with non-technical users

Performance Comparison (10M rows)

Operation Excel CSV Parquet
File Size ❌ Can't create 2.5 GB 500 MB (80% smaller)
Open Time ❌ Can't open 10 sec 2 sec (5x faster)
Filter Rows ❌ N/A 30 sec <1 sec (30x faster) ⚡
Search ❌ N/A 25 sec <1 sec (25x faster) ⚡
Sort ❌ N/A 60 sec 2 sec (30x faster) ⚡
Sum Column ❌ N/A 15 sec <1 sec (15x faster) ⚡

Why Parquet is Faster

Parquet uses columnar storage - it stores data by column instead of row. When filtering or searching, Parquet only reads the relevant columns, not the entire file. This makes column-specific operations 10-100x faster than CSV.

When to Use Each Format

Use Excel (.xlsx) When:

  • ✅ File has <100K rows (Excel performs well)
  • ✅ Need formulas (SUM, VLOOKUP, pivot tables)
  • ✅ Need formatting (colors, charts, visualizations)
  • ✅ Sharing with business users (universal format)
  • ✅ Creating reports (dashboards, presentations)

Don't use Excel when: File >1M rows (hard limit), Excel crashes/freezes, or need fast queries

Use CSV (.csv) When:

  • ✅ Need universal compatibility (any tool can open)
  • ✅ Simple data (no formulas, just values)
  • ✅ 1M-10M rows (Excel can't handle, but CSV can)
  • ✅ Exporting/importing between systems
  • ✅ Human-readable format needed

Don't use CSV when: File size is huge (>5 GB) - use Parquet instead

Use Parquet (.parquet) When: ⚡

  • ✅ 10M+ rows (big data)
  • ✅ Need speed (10-100x faster filtering/searching, especially for column operations)
  • ✅ Large files (Parquet is 80-90% smaller)
  • ✅ Repeated analysis (load once, query many times)
  • ✅ Data engineering (ETL pipelines, analytics)
Convert to Parquet →

Bottom Line: The 2025 Data Format Strategy

1. Use Excel for business reports (<1M rows, need formatting/formulas)

2. Use CSV for compatibility (sharing, universal access)

3. Use Parquet for big data (>10M rows, need speed)

Best workflow:

  • • Source data → Parquet (fast analysis)
  • • Analysis results → CSV/Excel (sharing)

One Tool for All: Diwadi converts between all formats automatically

Download Diwadi Free - Convert Any Data Format