How to Put Two Pictures Together (Phone, Browser, Desktop)

Open jpgjoiner.com, drop two photos, pick horizontal or vertical, download. Under 10 seconds, no app, no account. That is the whole process.

The rest of this page covers specific device instructions, layout decisions, and the one problem that ruins most merged photos (mismatched sizes).

On your phone (iPhone or Android)

Open jpgjoiner.com in your mobile browser - Safari, Chrome, whatever you already use. Tap the upload area and select two photos from your camera roll. Pick horizontal (side by side) or vertical (stacked). Hit download. Total time: about 15 seconds.

No app to install. No account. No watermark. The merge runs inside your browser, so your photos never leave your phone.

iPhone tip: if you take a screenshot or copy an image, you can paste it directly into the upload area with a long-press and "Paste." Saves the step of finding it in your camera roll.

Android tip: when the file picker opens, use the Files tab instead of the Google Photos tab. Google Photos sometimes downloads images from the cloud before handing them to the browser, adding a 3-5 second delay per photo. The Files picker grabs local copies instantly.

On a computer (Mac or Windows)

Same browser method works. Open jpgjoiner.com, drag two photos from your desktop onto the upload area, pick a layout, download. Ctrl+V (or Cmd+V on Mac) pastes screenshots directly from your clipboard - useful when putting together two screenshots for a bug report or presentation.

Preview on Mac (works offline)

Open the first image in Preview. Go to Tools > Adjust Size. Double the width (4032 becomes 8064 for a horizontal join) and uncheck "Scale proportionally." Undo to restore the image content while keeping the bigger canvas. Open the second image, Select All, Copy, paste it into the first, drag it to the right side.

The catch: Preview has no snap-to-edge. You will end up with a 1-2 px gap or overlap that only shows up after you export. For a quick offline merge it works, but the browser tool is more precise.

Paint on Windows (works offline)

Open the first image in Paint. Drag the right canvas handle to make room. Paste the second image and drag it into position. Save as JPG.

Paint re-encodes at a fixed ~85% quality that you cannot change. Black text develops faint compression halos that were not in the original. Fine for a quick email attachment. Not great for anything with readable text.

The browser tool is faster in every scenario I have tested, and it gives you a quality slider. The desktop apps exist as offline fallbacks - airplane, VPN issues, corporate proxy blocking external sites.

Side by side vs stacked - which to pick

Horizontal (side by side) for photos. Before-and-after comparisons, product shots, two headshots. The eye scans left to right naturally, so comparisons feel instant. If both photos are portrait orientation, horizontal creates a natural diptych without wasting space.

Vertical (stacked) for screenshots and documents. Stacking preserves the full width of each image, so text stays readable. Two phone screenshots placed side by side would shrink to half width and make 12 pt text into 6 pt. Stacking keeps everything legible. For screenshots with sharp text edges, the PNG merger gives lossless output without JPG compression artifacts.

One rule that has held up across every project: if both images are landscape, stack them. A horizontal join of two landscape images creates an extremely wide output (8000+ px) that looks like a panorama and overflows most screens. Stacking keeps the width reasonable.

Adding a gap or border between the two pictures

The default is flush - 0 px gap, edges touching. This works for most photos.

A white gap of 10 px creates clean visual separation. Useful when you want the viewer to see two distinct images rather than one continuous scene. Think diptych framing.

A black border gives a framed gallery look. Works well on white or light backgrounds where a white gap would disappear.

The customization panel on JPG Joiner has sliders for gap size and background color. For more structured layouts with borders, rounded corners, or drop shadows, the photo collage tool gives finer control.

What if the two pictures are different sizes?

This is the problem that makes most merged photos look broken. A 4000 px phone photo next to an 800 px web download produces an output where the small image is a tiny strip beside the large one. It looks like a bug, not a deliberate composition.

Three fixes, from simplest to most control:

1. Auto-align: the browser tool centers the smaller image against the larger one and fills the empty space with the background color. The result is usable but has visible padding bands.
2. Resize first: resize the larger image down to match the smaller one (or scale the smaller one up). Matching heights for horizontal joins or matching widths for vertical joins eliminates the padding entirely.
3. Crop to match: crop both images to the same dimensions before joining. Most precise result, but you lose parts of the images.

Resizing down is almost always better than resizing up. Scaling an 800 px image to 4000 px produces a blurry, interpolated mess. Scaling a 4000 px image to 800 px keeps it sharp.

Quality and file size

JPG compression shares its file header across the full image, so two merged photos are smaller than the sum of the originals. Two 4 MB photos at 92% quality produce roughly 6 MB merged, not 8 MB.

At 80% quality, the same merge drops to about 3.5 MB. Compression artifacts appear on sharp edges - text, architectural lines - but are invisible in organic textures like skin, grass, or fabric.

For WhatsApp or Instagram, 80% is fine. Both platforms recompress uploads to roughly 75% anyway, so starting at 92% buys you nothing except a larger upload. For email, printing, or archival, 92% preserves every visible detail without the file size penalty of 100%.

For a deeper comparison of all four merging methods (browser, phone shortcuts, desktop apps, command line), see the full guide to combining two photos.