Bulk Image Converter Convert multiple images to PNG, JPG, or WebP format in one batch operation.

What Is Bulk Image Converter?

A bulk image converter transforms multiple images from their current format to a chosen output format in a single batch operation. This is ideal when you have a collection of mixed-format images that all need to be in the same format. Choose from PNG (lossless, transparency), JPG (lossy, small files), or WebP (modern, best compression). Quality control is available for JPG and WebP. When converting to JPG, transparent areas are automatically filled with white.

Why Use Bulk Image Converter?

• Batch convert multiple images in one operation
• Choose between PNG, JPG, and WebP output
• Quality slider for lossy format control
• No server upload — fast, private processing

Common Use Cases

Format Standardization

Convert a mixed collection of images to a single consistent format.

WebP Migration

Batch convert website images from JPG/PNG to WebP for better performance.

Compatibility Fix

Convert WebP images to JPG for use with older software.

Archive Preparation

Convert images to PNG for lossless archival storage.

Technical Guide

Batch conversion processes each file sequentially through a shared canvas element. For JPEG output, the canvas is pre-filled with white to handle transparency. Quality is applied as the second parameter to canvas.toDataURL for JPEG and WebP. The output filename preserves the original name with the new extension. Sequential processing prevents memory exhaustion.

Tips & Best Practices

• 1
  WebP provides 25-35% smaller files than JPEG — ideal for web migration
• 2
  Use PNG when quality and transparency are essential
• 3
  Remove files you don't want to convert before processing
• 4
  Processing time increases with image count and size

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Frequently Asked Questions

Q What formats can I convert from?

Any image format your browser supports: JPG, PNG, WebP, BMP, GIF, and more.

Q Will quality be lost during conversion?

PNG is lossless. JPG and WebP are lossy — use the quality slider to balance.

Q Is there a limit on number of images?

No hard limit, but process in batches of 20-50 for optimal performance.

Q What happens to transparency when converting to JPG?

Transparent areas are filled with white since JPG doesn't support transparency.

Q Can I convert HEIC files?

HEIC support depends on your browser. For reliable HEIC conversion, use our dedicated HEIC to JPG tool.

About This Tool

Bulk Image Converter is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.