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Merge PNG images online

Combine two PNG files and keep transparency where possible. Layout, preview, PNG download.

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.

  • Preserves Transparency

    Merged PNG output keeps alpha channel transparency from both images — ideal for logos, icons, and graphic design assets.

  • Vertical & Horizontal Merge

    Combine PNGs vertically (top to bottom) or horizontally (side by side) with instant preview.

  • Lossless PNG Output

    Download merged images as high-quality, lossless PNG files with no compression artifacts.

  • 100% Client-Side

    All processing happens locally. Your images never leave your browser for complete privacy.

  • 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.
  • 01

    Match Image Sizes for Best Alignment

    Using images with the same dimensions produces the cleanest merge. Different sizes are centered but may leave gaps.

  • 02

    Choose Direction Based on Content

    Vertical works best for portrait-oriented images; horizontal for landscape or side-by-side comparisons.

  • 03

    Use for Transparent Assets

    PNG merging is ideal for transparent logos, icons, and graphics that need the alpha channel preserved in the output.

  • 04

    Check the Preview First

    Always review the live preview before downloading to confirm the alignment and layout look correct.

  • 05

    Resize Large Images First

    If your input images are very large, resize them first to keep the merged PNG at a manageable file size.

  • 06

    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.

Image Merge Tools Compared — Which One Fits Your Workflow

How this free PNG merge tool stacks up against other popular options.

  1. PineTools.com

    Merge PNG images preserving transparency. Simple but no preview.

  2. Imagy.app

    Merge PNG with alignment options. More controls than basic users need.

  3. OnlineConvert.com

    PNG merger with server processing. Free with ads.

  4. ILoveIMG.com

    PNG merge and combine. Popular but account walls for some features.

  5. Merge PNG

    Merge two PNG images with transparency preserved. Vertical or horizontal. Real-time preview. All processing in browser.

Perfect for These Use Cases

Common reasons to merge PNG images together.

  • Combine Logo Variations

    Merge horizontal and vertical logo versions, or combine logo mark with wordmark side by side.

  • Create Icon Sets

    Combine multiple icon designs into a single sprite sheet or preview image for client presentations.

  • Merge UI Mockups

    Combine multiple UI screenshots or design variations into one comparison image for sharing.

  • Social Media Graphics

    Merge transparent PNG overlays with photos or create multi-element social media posts.

  • Combine Scanned Documents

    Join multiple scanned document pages or receipts into a single, shareable PNG image.

  • 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.

  • No Software to Install

    Works entirely in your browser. No Photoshop, no image editors, no downloads required.

  • Transparency Preserved

    Unlike JPG mergers that produce opaque output, PNG merging keeps your alpha channels intact.

  • Lossless Quality

    PNG uses lossless compression, ensuring no quality degradation when merging images.

  • Complete Privacy

    Client-side processing means your images stay on your device — never uploaded to any server.

  • Works Everywhere

    Compatible with all devices — Windows, Mac, Linux, iPhone, Android, and iPad.

  • 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.
Canvas-Based Compositing
Uses HTML5 Canvas API to composite two images onto a single output canvas preserving alpha transparency.
Client-Side Only
All image processing and PNG encoding happens in your browser. No server communication whatsoever.
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.
Output: Lossless PNG
Download as a single PNG with full alpha transparency support using canvas.toDataURL("image/png").
Maximum Dimensions
Each source image limited to 8192px on longest edge. Merged output constrained to 8192px maximum.
Auto-Center Alignment
Images of different sizes are automatically centered along the perpendicular axis for a balanced look.

Sources & References

Authoritative references on the PNG image format, the Canvas rendering technology this tool uses, and transparent image compositing.
  • “Portable Network Graphics is a raster-graphics file format that supports lossless compression, supporting a full RGBA color space with optional transparency.”
    — Wikipedia — PNG

    PNG image format specification: This tool is designed specifically for PNG merging — preserving the lossless compression and alpha transparency that make PNG the preferred format for graphics and logos. en.wikipedia.org/wiki/PNG

  • “The Canvas API provides a means for drawing graphics via JavaScript and the HTML canvas element.”
    — MDN Web Docs — Canvas API

    Canvas API (client-side compositing with alpha): This tool uses Canvas 2D to composite PNG images while preserving their alpha channels — ensuring transparent areas remain transparent in the merged output. developer.mozilla.org/en-US/docs/Web/API/Canvas_API

  • “PNG supports lossless data compression, making it useful for storing graphics that need to be edited repeatedly without losing quality.”
    — W3C — PNG Specification (overview)

    PNG image format (W3C specification): The W3C PNG specification documents the format's lossless compression and alpha channel support — the core features that make PNG the ideal output format for this tool. w3.org/TR/PNG/

  • “Lossless compression is a class of data compression algorithms that allows the original data to be perfectly reconstructed from the compressed data.”
    — Wikipedia — Lossless compression

    Lossless compression for graphics: PNG uses lossless compression, preserving every pixel exactly — this tool merges multiple PNG images into a single PNG output, maintaining full quality and transparency. en.wikipedia.org/wiki/Lossless_compression

Frequently Asked Questions

Quick answers about this tool—open a question to read more.