Merge Images Vertically
Merge Images Vertically stacks selected images in selection order without resizing. Output height is the sum of heights and width is the widest image; narrower images are left-aligned and leave transparent space on the right. There is no spacing, centering, background, caption, reorder, or total-canvas safety check.
Runs locally — files stay on your deviceAre images centered horizontally?
No. Every bitmap starts at x=0 and is left-aligned.
Vertical concatenation accumulates y offsets
Each image begins after the total height of earlier images. The canvas width follows the maximum source width.
How it works
The browser decodes up to eight selected files, calculates maximum width and summed height, draws each at the next y offset, and exports PNG.
Key concepts
Order follows file selection
The first file appears at the top.
Widest input determines canvas width
Narrower inputs leave transparent right-side space.
When to use it
- Combine sequential screenshots.
- Create a simple before/after vertical sheet.
- Stack equal-width panels.
When not to use it
- Do not expect automatic width matching.
- Do not create extremely tall outputs without checking browser limits.
- Do not expect page breaks or PDF output.
Worked examples
Equal panels
- Input
Three 600×400 images- Expected output
600×1200 PNG
Widths match.
Mixed widths
- Input
600×400 and 400×400- Expected output
600×800 with transparent right area
Both are left-aligned.
Large set
- Input
12 files- Expected output
First 8 stacked
Additional files are ignored.
Common mistakes
Expecting centering
No x offset is calculated. Correction: Pre-pad or edit afterward.
Assuming infinite height
Browsers impose canvas/memory limits. Correction: Resize and merge in smaller groups.
Expecting a document
The result is one tall raster. Correction: Use PDF tools for paginated output.
Best practices
- Use matching widths.
- Select in top-to-bottom order.
- Estimate total height and memory.
Related operations and differences
Merge Images Horizontally
Choose Merge Images Horizontally when you need to join up to eight images side by side.; use Merge Images Vertically specifically for merge vertical.
Add Text Watermark to Image
Choose Add Text Watermark to Image when you need to place a text watermark in the lower-right corner.; use Merge Images Vertically specifically for merge vertical.
Adjust Image Brightness
Choose Adjust Image Brightness when you need to increase or decrease image brightness.; use Merge Images Vertically specifically for merge vertical.
Adjust Image Contrast
Choose Adjust Image Contrast when you need to increase or decrease image contrast.; use Merge Images Vertically specifically for merge vertical.
Adjust Image Saturation
Choose Adjust Image Saturation when you need to control the intensity of image colors.; use Merge Images Vertically specifically for merge vertical.
Crop Image
Choose Crop Image when you need to crop an image to an exact local pixel rectangle.; use Merge Images Vertically specifically for merge vertical.
Limitations and privacy
- First eight images only.
- No resizing, centering, spacing, captions, backgrounds, reorder UI, pagination, or total-canvas guard.
- PNG output.
Selected images are decoded and processed locally in this browser.
Frequently asked questions
How many images are merged?
Up to the first eight.
Are widths normalized?
No.
Are narrow images centered?
No.
Can it create a PDF?
No.