Merge PNGs vertically or horizontally
Stitch multiple PNGs together in your preferred order—either vertically (top-to-bottom) or horizontally (left-to-right). Perfect for transparent images, layouts, or screenshots. We process everything in your browser, keeping your files secure.
Choose PNG files
Drag and drop multiple files at once
How to use
- 1
Drag and drop the PNG files you want to combine, or click to select. Upload them in the sequence you want them joined.
- 2
Choose the merge direction (vertical or horizontal) to set the alignment.
- 3
If files have different dimensions, adjust alignment settings. Align vertical images by width (scale to narrowest or widest) and horizontal ones by height (scale to shortest or tallest). We output a PNG, preserving transparent areas automatically.
- 4
Click "Merge images" to generate your combined PNG, and download it immediately.
FAQ
- How do you determine the order of the merged images?
- We join PNGs in the exact sequence you upload them. To change the order, remove the files and add them back in your desired sequence.
- What happens if my screenshots have different sizes?
- We align vertical images by width and horizontal ones by height. If you select "Scale to narrowest/shortest," we scale larger images down. If you select "Scale to widest/tallest," we pad smaller images with transparent space.
- Do you preserve transparent PNG backgrounds?
- Yes. We save the final output as a PNG, keeping all original transparent regions intact. Any border space created by different image sizes also remains transparent.
- Do you upload my PNGs to a server?
- No. We merge your images locally on your device. We never upload files to a server, and they clear from memory as soon as you close the page.
Stacking Images While Keeping Transparency
This joins several PNGs vertically into one image. The output looks the same as a JPG merge, with one decisive difference: PNG carries an alpha channel, so transparent regions in your sources survive the merge intact.
Keep the output format as PNG and transparent stays transparent. Switch the output to JPG and every transparent area is filled with a background colour the moment you convert. If you're stacking icon sets or cut-out images, check that format setting before you start.
The Trap When Merging Transparent Images
When your sources have different widths, the leftover space beside the narrower ones also stays transparent. The result looks fine on its own, but place that image on anything other than white later and it won't look the way you pictured.
That makes the background setting a real decision: keep the transparency, or commit to a specific fill colour now. If you already know where the result is going, filling with that background colour is safer. If it's a reusable asset headed to several places, leaving it transparent keeps your options open.
There Is a Ceiling on Merged Size
Stacking vertically keeps adding height, and the longest side a browser can draw in one pass is 16,384px. The number of files per merge is capped at 30. When a job would exceed either limit, the tool tells you up front instead of failing partway through.
The arithmetic makes it concrete: at 2,000px tall each, eight images already reach 16,000px. If you hit the ceiling, resize the sources first or split them into two batches and merge each.
When a PNG Merge Gets Heavy
PNG preserves your originals exactly, but the merged file can get large — and how large depends enormously on what the images contain. Here is the same-sized image saved by type.
| Image type | PNG | JPG quality 80 | Is PNG the better pick? |
|---|---|---|---|
| Icons and logos (few colours) | 23 KB | 29 KB | Yes — smaller and lossless |
| Screenshots (mostly text) | 94 KB | 97 KB | Yes — similar size, lossless |
| Photographs (full background) | 3,591 KB | 269 KB | No — substantially worse |
For icons and screenshots, staying with PNG costs you nothing in size. If you're stacking photographs, though, the PNG result gets genuinely heavy — and provided none of them rely on transparency, switching the output to JPG is the practical call.
Matching Widths Removes the Alignment Question
Different widths create gaps beside the narrower images and force you to pick left, centre, or right alignment. The cleanest answer is to resize everything to a common width before merging — then neither alignment nor fill colour matters.
Work Where Transparency Must Survive
- Bundling several transparent icons into a single sprite sheet
- Joining UI captures in order to show one continuous user flow
- Consolidating text- and table-heavy material into one image without smearing
- Posting several images somewhere that accepts only one
Related guides
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How to Combine Images into One PDF (and What to Watch For)
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