Merge Images Online into One

Merge multiple images into one image online. Combine JPG and PNG files horizontally or vertically with ease.

Max 50MB   •   Accepted: .jpg,.jpeg,.png

Composite Canvas Mechanics

Stitch Multiple Raster Images Along Unified Coordinate Axes

Merging multiple graphics requires constructing a new raster bounding canvas that dynamically matches the geometry of all input files. In horizontal mode, the overall canvas width equals the combined sum of individual image widths (∑ Widthi), while the canvas height expands to accommodate the tallest constituent image.

In vertical stacking mode, the total canvas height equals the sum of all heights (∑ Heighti), with the width anchored to the widest file. The engine calculates precise offset coordinates for each sub-image, rendering them sequentially into the shared pixel buffer.

Horizontal Side-by-Side Width = W1 + W2
Image 1
+
Image 2
Vertical Stacking Height = H1 + H2
Image 1 (Header)
Image 2 (Body)
Input A: JPG (RGB 24-bit)
No Alpha
Input B: PNG (RGBA 32-bit)
8-bit Alpha Channel

Pixel Buffer Normalization

sRGB Gamut Harmonization & Alpha Transparency Preservation

Profile Normalization

Harmonize Color Profiles and Alpha Transparency

When joining pictures from different cameras, scanners, or design tools, inputs often carry mismatched color profiles (such as Adobe RGB vs sRGB) or incompatible pixel modes (RGB without transparency vs RGBA with alpha channels).

ScanPDF normalizes the constituent images into a unified sRGB color space to prevent unwanted color shifts or washed-out tones in the final stitched document. If any source file contains transparency, alpha blending ensures transparent margins blend smoothly without black borders or jagged edges.

Image Merging Features

Flexible layout controls for creating before-after comparisons, collage panels, and continuous scrolls.

Side-by-Side Horizontal

Place images in a continuous horizontal row, ideal for before/after comparisons and landscape photo pairing.

Vertical Stacking

Stack images vertically into a clean vertical roll, perfect for multi-panel webtoons and sequential guides.

Sequence Sorting

Easily rearrange file order in your browser before merging to guarantee proper story progression.

Native Resolution

Retains the full native pixel dimensions of your source files without artificial downsampling or quality compression.

How to Merge Images Online

Combine two or more images into a single picture in four simple steps.

1

Select Images

Upload 2 or more JPG, PNG, WebP, or BMP files into the tool dropzone.

2

Set Direction

Choose Horizontal (side-by-side) or Vertical (stacked) stitching.

3

Arrange Order

Drag or reorder uploaded file cards to ensure the correct visual sequence.

4

Download Image

Click merge and download your single, high-resolution composite image file.

2 Files Selected • Direction: Horizontal
Mode: Side-by-Side

before.jpg + after.jpg

Canvas Output: 3840 × 1080 px

Practical Applications & Scenarios

Ideal for commercial portfolios, business expense reports, social media, and creative projects.

Before & After Comparisons

Create striking side-by-side showcases for renovation projects, fitness milestones, graphic retouching, and medical case studies.

Receipt & Invoice Bundles

Stack multiple payment receipts or expense tickets into a single vertical image for quick expense reimbursement submission.

Multi-Panel Comics

Join individual illustrated comic cells or webtoon strips into a continuous vertical image optimized for mobile scrolling.

Step-by-Step UI Tutorials

Assemble software screenshots into a clear, numbered sequence for technical documentation and customer onboarding guides.

Why Choose ScanPDF Image Merger?

Built for seamless composite assembly without quality compromises.

Full Native Resolution

No artificial downscaling. Source pictures maintain their original pixel dimensions and sharp detail.

Mixed Format Engine

Combine JPEGs, transparent PNGs, WebP files, and BMPs in the same batch without manual conversion.

Zero Cloud Footprint

Files are processed in temporary sandboxes and automatically deleted after your composite download.

Canvas Alignment & Sizing Recommendations

  • Mismatched Dimensions: If you merge images of significantly different heights in horizontal mode, the canvas adapts to the tallest image. Consider resizing or cropping them beforehand for symmetric side-by-side alignment.
  • Output Memory Considerations: Stitching multiple 24-megapixel camera files together produces an extremely large composite bitmap (often exceeding 10,000 pixels across). Use our Compress Image tool afterward if smaller file sizes are needed.
  • Format Selection: If any of your images have transparent backgrounds, download the result as PNG to preserve transparent margins.