What is Zap?

Zap is an image optimization application that makes it easy to compress images while maintaining quality. It features a simple drag-and-drop interface for batch processing multiple images at once.

Which image formats does Zap support?

Zap supports the most common image formats:

• PNG - Lossless/lossy compression using PNGQuant (fast, configurable quality) or OptiPNG (lossless, adjustable optimization levels)
• JPEG/JPG - Lossy compression using MozJPEG with configurable quality settings and progressive encoding
• GIF - Lossless compression using Gifsicle with adjustable optimization levels and color reduction
• SVG - XML optimization using SVGO, removes unnecessary metadata while preserving structure
• WebP - Modern image format compression with optimized quality settings (static only for now!)

How do I use Zap?

Getting Started

1. Drag and Drop: Simply drag image files from Windows Explorer and drop them onto the Zap window
2. Select Files: Click the "Select Files" button to browse and choose images
3. Automatic Optimization: Files are automatically optimized when added to Zap

Basic Operations

• Clear: Remove all files from the current queue
• Run Again: Re-optimize selected files with current settings
• Select/Deselect: Click checkboxes to choose which files to process
• Context Menu: Right-click files for additional options like opening in Explorer or reverting changes

What are the optimization settings?

General Settings

• Strip PNG Metadata: Remove EXIF and other metadata from PNG files
• Strip JPEG Metadata: Remove EXIF and other metadata from JPEG files
• Preserve File Permissions: Keep original file permissions after optimization
• Preserve File Dates: Maintain original creation/modification dates

Quality Settings

• Enable Lossy Minification: Must be enabled to adjust quality settings. When disabled, lossless compression is used.
• JPEG Quality: 40-99% (automatically clamped to avoid quality issues)
  • Default: 80%
• PNG Quality: 40-100%
  • Lower values = smaller files but reduced quality
  • Default: 80%
• GIF Quality: 40-100%
  • Affects color palette size (64-256 colors)
  • Default: 80%

Optimization Speed

Choose between four optimization levels:

• Fast: Quick processing with basic compression
• Normal: Balanced speed and compression
• Extra: Thorough optimization (recommended)
• Insane: Maximum compression, slowest processing

Output Mode

• In-place: Overwrites original files with optimized versions
• Copy: Creates optimized copies with "-optimized" suffix

Cache Handling

• Keep: Retains temporary files for faster re-processing, this also allows you to fetch the original if you need it before clearing the queue or closing Zap.
• Delete: Removes temporary files after optimization

How much can Zap reduce file sizes?

File size reduction varies based on:

• Original image format and compression
• Image content (photos vs. graphics)
• Selected quality settings
• Optimization level

Typical savings range from 20-80% depending on these factors. Zap tracks your lifetime savings showing total space saved across all optimizations.

Can I revert optimized images?

Yes! If you optimized files in "in-place" mode, you can right-click and select "Revert to Original" to restore the original file. This works until you close the app or clear the file list.

Does Zap support batch processing?

Yes, Zap is designed for batch processing. You can:

• Select and drop multiple files at once
• Process hundreds of images in a single operation
• Use multi-threading for faster processing of large batches

Where are optimized files saved?

For files selected via "Select Files" button:

• In-place mode: Original files are overwritten
• Copy mode: Optimized versions saved in same folder with "-optimized" suffix

Is my data safe?

Yes! Zap:

• Processes all images locally on your computer
• Never uploads images to external servers
• Creates backups when using in-place mode (for revert functionality)
• Preserves file permissions and dates when configured

Can I customize compression algorithms?

Yes, in Advanced Settings you can:

• Enable/disable specific compression algorithms (MozJPEG, PNGQuant, OptiPNG, etc.)
• Adjust quality settings for each format
• Choose optimization speed vs. compression ratio
• Configure metadata handling

What's the difference between PNGQuant and OptiPNG?

• PNGQuant: Lossy compression that can significantly reduce file size by reducing colors. Faster but may slightly alter image appearance.
• OptiPNG: Lossless compression that maintains exact image quality. Slower but preserves perfect fidelity.

If both are enabled, Zap will automatically compare both algorithms against the image to determine which one provides the best quality to size ratio.

Does Zap work with other image tools?

Yes! Zap can be used alongside other tools in your workflow. It uses industry-standard compression libraries that maintain compatibility with all image viewers and editors.