100%
100% Client-Side Processing - No Image Uploads

About This Image Overlay Tool

This professional image composition tool allows you to layer multiple images and text elements directly in your browser. All processing happens locally on your device using HTML5 Canvas technology—your images never leave your computer. For precise adjustments, you might also find our image cropper useful for preparing base images before compositing.

Typical Use Cases

  • Social Media Graphics: Create branded images with logos, watermarks, and text overlays. Consider using the image watermarker for dedicated branding workflows.
  • Web Design Mockups: Layer interface elements on background images
  • Photo Editing: Add decorative elements, text captions, or composite images. For final touches, the image filters tool can enhance the overall look.
  • Marketing Materials: Create promotional images with overlayed text and graphics
  • Personal Projects: Design collages, invitations, or digital artwork

How the Processing Works

The tool uses your browser's built-in HTML5 Canvas API to handle all image operations:

  1. Local Loading: Images are read directly from your device using FileReader API
  2. Canvas Rendering: All layers are drawn onto a canvas element with precise positioning
  3. Real-time Preview: Changes are immediately rendered without server communication
  4. Client-side Export: Final composition is converted to download format in your browser

No server processing means faster editing and complete privacy for your images.

Image Quality & Format Behavior

Output Quality Considerations

Tip: For photographic content, JPG at 85-95% quality offers the best balance of quality and file size. For graphics with text or transparency, use PNG format. You can also optimize web images further with the image compressor tool after export.
PNG Format (Lossless)
  • Preserves transparency (alpha channel) - ideal for logos and graphics
  • Lossless compression - no quality degradation on export
  • Larger file sizes compared to JPG for photographic content
  • Recommended for: Graphics, text overlays, images requiring transparency
JPG Format (Lossy)
  • Quality slider controls compression (10-100%)
  • Higher compression = smaller files but visible artifacts
  • No transparency support - background becomes white if base image is missing
  • Recommended for: Photographs, complex images, web optimization
Note on Image Resizing: When enlarging overlay images beyond their original dimensions, some quality loss may occur due to pixel interpolation. For best results, use overlay images at or near their intended display size.

Technical Specifications

Supported Input Formats

JPG JPEG PNG GIF WEBP BMP

Most modern image formats are supported through browser's native image decoding. For format conversion needs, try our dedicated image converter.

Resolution & Dimension Handling

  • Base image determines the canvas dimensions
  • Overlays can be scaled independently while preserving aspect ratio
  • No upscaling limits but quality degrades with extreme enlargement
  • Export maintains the original base image resolution

Performance Notes

  • Works entirely in browser memory (RAM)
  • Very large images (>10MP) may affect performance on low-memory devices
  • Undo/redo history is stored in memory during session
  • No persistent storage - refresh clears all work

Privacy & Security

Your Images Stay on Your Device
  • Zero uploads - all processing happens locally
  • No tracking of your images or edits
  • No account required - completely anonymous use
  • Works offline after initial page load
  • No data sent to external servers during editing

The tool uses standard browser APIs that operate within the same security sandbox as other web applications. Your images are processed in memory and can only be saved when you explicitly click download.

Quick FAQ

Why does my exported JPG look different from the preview?

JPG compression can introduce subtle artifacts, especially at lower quality settings. The canvas preview shows uncompressed data, while JPG export applies lossy compression. Use PNG for pixel-perfect exports.

Can I edit transparent PNG files?

Yes, transparency is fully supported. Upload PNG files with transparency as overlays, and export as PNG to preserve the alpha channel. JPG exports will fill transparency with white.

Why is my image pixelated when I enlarge it?

Enlarging raster images beyond their original resolution causes interpolation. For best results, use overlay images at their intended display size or source higher resolution images.

Where are my images stored during editing?

All images are kept in your browser's temporary memory (RAM). They are not saved to disk until you download the final composition. Refreshing or closing the page clears all data.

Tool updated: April 2025
Compatible with Chrome, Firefox, Safari, Edge (latest versions)