Your gallery app can't do this. A browser can: drop two or more photos into WhizPDF's image merger, pick the Side by side layout, set the spacing and background color, and download one combined PNG — free, no watermark, no app to install.
Put photos side by side: click "Choose files" above to upload your photos and get back one combined PNG.
This is the layout most comparisons need: before-and-after shots, two angles of a product for your listing, the kids' school pictures side by side for the grandparents. Your phone's own apps either skip it entirely or lock you into a template. Both routes are below, plus the details that separate a clean comparison from a lopsided collage.
Why your phone's built-in apps fall short
Start with what you already own, because both platforms get close but stop short:
- iPhone — The Photos app has no combine feature at all. The workaround is Apple's Shortcuts app: it includes a Combine Images action that merges photos horizontally, vertically, or in a grid once you build the shortcut. Capable, but you have to assemble the shortcut yourself before your first merge.
- Android — Google Photos makes collages of up to six photos, but you pick a template and the template picks the layout. There's no free-form spacing, no custom background color — the template decides how your photos sit.
For a quick social post, either works. For a comparison that needs to read left-to-right — before on the left, after on the right, same framing, one thin gap — you want control over the layout, not a template's opinion. That's what a dedicated merger gives you.
Put photos side by side in three steps
- Upload your photos. Drag in or select at least two — JPG, PNG, and BMP all work, and you can reorder them afterward by dragging.
- Choose the Side by side layout to merge images side by side into one row.
- Merge and download. You get a single PNG that keeps each photo's proportions — nothing gets stretched or squashed to match its neighbor.
The finishing options live next to the layout picker. Three matter for a comparison:
- Spacing — 0 to 80 px. Zero removes the gap entirely, so the photos sit flush edge to edge; around 16 px gives each photo breathing room.
- Background color — fills the canvas and any gaps. White is the default; black suits screenshots with dark themes.
- Order — drag the thumbnails so the left-to-right reading order matches your comparison.
That last point matters more than it sounds. Side-by-side and vertical layouts center each photo on the shared canvas with its proportions intact, so a portrait shot next to a landscape shot stays honest — no cropping, no distortion.
Grid and vertical: the other two layouts
Side by side is one of three ways to combine photos into one, and the choice is really about how many photos you have and what the row should say:
- Side by side — two or more photos in one horizontal row (the merger takes up to 30 per batch). Best for before/after pairs and A-or-B comparisons where reading order carries meaning.
- Vertical stack — photos stacked top to bottom into one long image. Best for step-by-step screenshots and chat histories, where the sequence reads downward. The canvas adapts to your widest image; narrower ones keep their size.
- Grid — equal-size cells with 2 to 6 images per row. Best for product angle sets and four-to-six photo roundups. Here you also choose how each image sits in its cell: Fit shows the whole photo and pads the difference with background color, while Fill center-crops until the cell is covered. Fit is the default and the right call for comparisons; Fill suits collages where uniform cropping looks tidier than padding.
The details that make a side-by-side look professional
The merge takes seconds; making the comparison read well takes ten extra seconds of thought:
- Before goes on the left. The eye reads left to right — reversed, your "after" reads as the "before." Check the thumbnail order before merging.
- Crop to matching framing first. A wide pull-back shot next to a close-up reads as two different scenes. Crop both to roughly the same field of view before uploading.
- Keep the gap thin. One small gap — the default 16 px is a good starting point — reads as intentional. Zero creates a seamless split, which works for wall-color comparisons; wide gaps make the pair look unrelated.
- Match the background to the photos. White gaps disappear against product shots on white; against screenshots, try black. The background color picker handles either.
When the result doesn't come out right
- One photo towers over the other. That's proportion mismatch, and the fix is structural: side-by-side layouts keep every photo's proportions and center it, so nothing distorts. If you want them to occupy identical boxes instead, switch to grid mode and pick Fit — the shorter image gets background padding, not stretching.
- Your files get rejected as unsupported. Photos saved from some websites come down as WebP, which this merger doesn't accept alongside JPG, PNG, and BMP. Convert a WebP to JPG first — a few seconds per file — then merge.
- Transparent areas take on the background color. The merged PNG is opaque by design: transparent areas composite onto whatever background color you picked — white only if you leave it on the default. If a logo needs its transparency after merging, the merge isn't the right last step — keep the original file for that use.
- The download looks softer than expected. Very large inputs get scaled down proportionally to stay within safe output dimensions — each source photo can be up to 40 megapixels, 60 across the selection. Starting from a screenshot instead of the original photo is the other common cause: screenshots carry screen resolution, not camera resolution.
If the merged PNG comes out heavier than you need for upload — some forms and listings cap file size in megabytes, not pixels — run it through a tool that can compress a PNG that came out too big. The compressor rescales and re-encodes the image to hit smaller sizes, so give the result a quick look before you upload it anywhere that matters.
Use a browser tool that merges images: upload both photos, pick the Side by side layout, set the spacing, and download the combined PNG — no sign-up, no watermark.
The Photos app has no combine feature. You can build a shortcut with the Combine Images action in Apple's Shortcuts app, or open a browser merger in Safari — no app install either way.
Google Photos can make a collage of up to six photos, but the template controls the layout. For a clean side-by-side row with your own spacing and background, a browser merger gives you the control the templates don't.
Photos taken at different distances or orientations have different proportions. Side-by-side layouts preserve each image's proportions and center it on a shared canvas; in grid mode, Fit shows the whole image while Fill crops it to match the cell.
Some mergers accept JPG, JPEG, PNG, and BMP only. Convert a WebP to JPG first — it takes seconds in a browser converter — then merge the JPGs as normal.
The merger outputs a single PNG. It is opaque: transparent areas of your source images get composited onto the background color you picked, white by default.
Yes. The merge runs on WhizPDF's servers, so your photos are uploaded when you start the job. They aren't shared or published — only you get the merged download. If you'd rather keep everything on-device, the Shortcuts and Google Photos routes above never leave your phone.
References
- Apple Shortcuts User Guide — the Shortcuts app and its built-in actions, including Combine Images for merging photos on iPhone.
- Google Photos — Make & edit collages — Google's documentation on the template-driven collages behind Photos' built-in collage route.