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Merge PNG — combine PNG images online

Free online PNG merger. Combine PNG images, join multiple PNG files, merge transparent images vertically or horizontally. No upload, instant download, all in browser.

What is a PNG Merger?

A PNG merger is an online tool that combines two PNG images into a single, lossless PNG file. Unlike JPG merging that compresses images with quality loss, PNG merging preserves the full transparency channel and produces perfectly sharp output. All processing happens using HTML5 Canvas in your browser — your images are never uploaded to any server. The tool supports vertical merging (images stacked top-to-bottom) and horizontal merging (side-by-side), automatically centering images of different sizes for a clean, balanced composition.

Merge PNG Features

Combine, join, and merge PNG images with these powerful features.

  1. Preserves Transparency: Merged PNG output keeps alpha channel transparency from both images — ideal for logos, icons, and graphic design assets.
  2. Vertical & Horizontal Merge: Combine PNGs vertically (top to bottom) or horizontally (side by side) with instant preview.
  3. Lossless PNG Output: Download merged images as high-quality, lossless PNG files with no compression artifacts.
  4. 100% Client-Side: All processing happens locally. Your images never leave your browser for complete privacy.
  5. Instant Preview: See the merged result immediately as soon as both images are uploaded. No waiting required.

How to Merge PNG Files Online

Three quick steps to combine your PNG images into one file.

  1. 1. Upload Your PNG Images: Drag and drop your first PNG into the top upload zone, and the second PNG into the bottom zone.
  2. 2. Choose Merge Direction: Select vertical to stack images or horizontal to place them side by side. Preview updates in real-time.
  3. 3. Download the Merged PNG: Click Download PNG to save your combined image as a single, lossless PNG file.

Tips for Merging PNG Images

Best practices for getting clean merged PNG results.

  1. Match Image Sizes for Best Alignment: Using images with the same dimensions produces the cleanest merge. Different sizes are centered but may leave gaps.
  2. Choose Direction Based on Content: Vertical works best for portrait-oriented images; horizontal for landscape or side-by-side comparisons.
  3. Use for Transparent Assets: PNG merging is ideal for transparent logos, icons, and graphics that need the alpha channel preserved in the output.
  4. Check the Preview First: Always review the live preview before downloading to confirm the alignment and layout look correct.
  5. Resize Large Images First: If your input images are very large, resize them first to keep the merged PNG at a manageable file size.
  6. Consider Canvas Color: Transparent areas between merged images show the checkerboard background in the preview. This is accurate — the actual PNG download will be transparent.

Perfect for These Use Cases

Common reasons to merge PNG images together.

  1. Combine Logo Variations: Merge horizontal and vertical logo versions, or combine logo mark with wordmark side by side.
  2. Create Icon Sets: Combine multiple icon designs into a single sprite sheet or preview image for client presentations.
  3. Merge UI Mockups: Combine multiple UI screenshots or design variations into one comparison image for sharing.
  4. Social Media Graphics: Merge transparent PNG overlays with photos or create multi-element social media posts.
  5. Combine Scanned Documents: Join multiple scanned document pages or receipts into a single, shareable PNG image.
  6. Game Asset Sprite Sheets: Combine individual game sprites into a single spritesheet PNG for game development.

Why Use This PNG Merger

Advantages of this free, browser-based PNG merge tool.

  1. No Software to Install: Works entirely in your browser. No Photoshop, no image editors, no downloads required.
  2. Transparency Preserved: Unlike JPG mergers that produce opaque output, PNG merging keeps your alpha channels intact.
  3. Lossless Quality: PNG uses lossless compression, ensuring no quality degradation when merging images.
  4. Complete Privacy: Client-side processing means your images stay on your device — never uploaded to any server.
  5. Works Everywhere: Compatible with all devices — Windows, Mac, Linux, iPhone, Android, and iPad.
  6. 100% Free, No Limits: No sign-ups, no watermarks, no usage caps. Merge as many PNG files as you need.

Technical Details

How the PNG merger works under the hood.

  1. Canvas-Based Compositing: Uses HTML5 Canvas API to composite two images onto a single output canvas preserving alpha transparency.
  2. Client-Side Only: All image processing and PNG encoding happens in your browser. No server communication whatsoever.
  3. Supported Input Formats: PNG, JPG, JPEG, WebP, GIF. Files up to 15 MB each. Images auto-scale if exceeding 8192 pixels on the longest edge.
  4. Output: Lossless PNG: Download as a single PNG with full alpha transparency support using canvas.toDataURL("image/png").
  5. Maximum Dimensions: Each source image limited to 8192px on longest edge. Merged output constrained to 8192px maximum.
  6. Auto-Center Alignment: Images of different sizes are automatically centered along the perpendicular axis for a balanced look.

Frequently Asked Questions

Have questions? We have answers.

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