Compression

Automatically compress response bodies using gzip to reduce bandwidth and improve load times.

Quick Start

import { Server } from 'balda';

const app = new Balda({
  plugins: {
    compression: {
      threshold: 1024,
      level: 6,
    }
  }
});

Configuration

Basic Options

compression({
  threshold: 1024,  // Only compress responses larger than 1KB
  level: 6          // Compression level (0-9)
})

Custom Content Type Filtering

compression({
  threshold: 2048,
  level: 9,
  filter: [
    /text\/.+/,
    /application\/json/,
    /application\/javascript/
  ]
})

Options

Option	Type	Default	Description
threshold	number	1024	Minimum response size in bytes to trigger compression
level	number	6	Compression level (0 = no compression, 9 = maximum)
filter	RegExp[]	Common text types	Content types to compress (regex patterns)

Default Compressible Types

By default, compression applies to:

• All text types (text/*)
• JSON (application/json, application/*+json)
• JavaScript (application/javascript)
• XML (application/xml, application/*+xml)

How It Works

1. Checks if client supports gzip via Accept-Encoding header
2. Verifies response size exceeds threshold
3. Matches content type against filter patterns
4. Compresses response body using gzip
5. Sets Content-Encoding: gzip header

Performance Tips

• Lower threshold for faster networks (512 bytes)
• Higher threshold for slower networks (2048+ bytes)
• Level 6 balances speed and compression ratio
• Level 1-3 for CPU-constrained environments
• Level 9 for maximum bandwidth savings

Example: Production Config

const app = new Balda({
  plugins: {
    compression: compression({
      threshold: 1024,
      level: 6,
      filter: [
        /text\/.+/,
        /application\/json/,
        /application\/javascript/,
        /image\/svg\+xml/
      ]
    })
  }
});