Combining two images is straightforward when you decide the purpose before opening an editor. A comparison needs clear separation, a sequence needs an obvious reading order, and a blended composite needs compatible light and perspective. Making that choice first prevents unnecessary cropping and correction later.
The same method works in any capable editor, covering side-by-side layouts, vertical stacks and layered blends without relying on a particular application.
Choose a Layout That Fits the Purpose
Side by side
A side-by-side layout is the clearest option when viewers need to compare two subjects. It suits before-and-after views, alternative designs, paired portraits and contrasting scenes. Place the images on one horizontal canvas and give them equal visual weight unless one is deliberately the main image.
Match the height of both panels and crop their widths as needed. Do not stretch either image to fill its space, because distortion is especially noticeable in faces, lettering and circular objects. A narrow gap or neutral divider helps when similar colours meet at the join.
For a comparison, keep the viewpoint and crop as consistent as the source files allow. If one view shows an entire room and the other shows one corner, readers cannot judge the change reliably. Put the earlier state first for audiences who read from left to right.
Vertical stack
A vertical stack works better when the final image will be viewed on a narrow screen or when each photograph is naturally wide. Match the panel widths, place the first image above the second and use the same gap between them that you would use in a horizontal layout.
Very tall photographs may be clearer as shorter crops centred on their subjects. Keep repeated features, such as a horizon, in comparable positions where possible.
Layered blend
A layered blend is suitable when the aim is one continuous scene rather than a direct comparison. It can combine a subject with a new background or create a gradual transition between related views. Choose source images with compatible direction of light, camera angle and apparent scale.
Look closely at the overlap before committing to this approach. Busy textures, intersecting outlines and conflicting shadows make a blend difficult to read. Guidelines for avoiding mergers in composition are useful when deciding where important edges should meet or remain separate.
Prepare Both Images
Protect the original files
Work from copies and keep an editable master with separate layers. A flattened export is useful for sharing, but it should not be the only saved version. Separate layers let you revise a crop, restore a masked area or change the gap without rebuilding the composition.
Check that both files are large enough for the planned output. Enlarging a small image can make detail look soft, while reducing a large image is usually less troublesome. Compare the files at their actual pixel size rather than judging them only in a zoomed-out preview.
Match proportions and framing
For equal side-by-side panels, crop both images to the same aspect ratio and height. For a stack, use the same aspect ratio and width. If one subject needs more room, use unequal panels deliberately instead of disguising the difference with stretching.
Crop around the subject with the join in mind. Leave space in front of a face that looks to one side, and avoid pressing a hand, head or product edge against the divider. Align repeated features such as eye level, horizons or architectural lines when they help the relationship between the images.
Bring light and colour closer
Compare neutral areas first. If white clothing looks blue in one image and yellow in the other, adjust temperature and tint before changing saturation. Then compare exposure, highlights and shadows. The goal is not to make the photographs identical, but to prevent an avoidable technical mismatch from distracting the viewer.
Make modest corrections to each source image before combining them. Save any overall colour treatment until the composition is assembled, because one final adjustment can help both panels feel consistent. Avoid a strong filter that hides detail or creates unnatural skin and object colours.
Build the Combined Image
Set the canvas
Choose the final dimensions before placing the images. For two equal panels side by side, the canvas width is the combined width of both panels plus any centre gap and outer margins. For a vertical stack, add the panel heights instead. This simple calculation avoids resizing the finished design more than once.
Choose a transparent or neutral background to suit the output format and image edges. Patterns can compete with fine detail and make narrow gaps look uneven.
Place and align the layers
Import each image as a separate layer. Resize from a corner while preserving its aspect ratio, then use guides or alignment controls to level the shared edges. Zoom in at the join to check for a one-pixel gap, accidental overlap or an uneven divider.
If the panels are meant to be equal, measure their dimensions rather than relying on sight. If they are intentionally unequal, make the hierarchy obvious. A slight difference often looks like an error, while a clearly larger main panel reads as a deliberate choice.
Match corner shapes, borders and label positions across both photographs. Do not fill empty areas with effects; open space helps separate the focal points.
Blend with masks rather than erasing
For an overlapping composite, place the image that should appear in front on the upper layer. Add a mask and hide unwanted areas on the mask instead of deleting pixels. This keeps the edit reversible and allows the boundary to be refined later.
Use a soft brush for irregular edges and a gradient for a broad transition. Build the blend gradually, checking the subject outline as well as the surrounding texture. A detailed layer-mask photo blending workflow can help clarify the relationship between masks, brushes and gradients.
Inspect hair, fingers, foliage and reflective surfaces at full size. Hard cut-outs can leave halos, while an overly soft mask can make the subject appear blurred. Restore or conceal small areas on the mask until the edge matches the sharpness of the source image.
Shadows also need to agree with the new scene. A subject lit from the left will look misplaced against a background lit strongly from the right. When the source lighting cannot be reconciled without heavy alteration, a separated panel layout is the clearer solution.
Add Only Useful Presentation Details
Borders, labels and spacing
Use a border when the image edges need separation. Keep its width consistent and choose a colour that contrasts gently with both photographs. An outer margin can frame the whole composition, but it should not reduce the panels so much that important details become difficult to see.
Labels should explain a relationship that is not obvious. Place terms such as Before and After in matching positions, with clear contrast and no obstruction of important details.
For captions, use one typeface with a clear heading and supporting style. Decorative lettering and oversized icons distract from the images. Add an arrow only when the viewing order is unclear.
Check visual balance
View the composition at full size and as a small thumbnail. At full size, look for rough edges, noise, blur and colour mismatches. At thumbnail size, check whether one panel dominates unintentionally or both subjects compete for attention.
If one side feels heavy, adjust the crop, scale or open space before changing colours. A bright object near an edge can carry as much visual weight as a larger, darker subject. Composition advice on balance and focal points can help identify crowded edges and competing subjects.
Keep background lines away from faces and other recognisable features. Where two similar outlines touch, separate them with a small gap, a change in position or a restrained divider. In a realistic composite, check that relative size and perspective make sense for the apparent distance.
Export and Check the File
Choose the format according to the content and destination:
- JPEG suits photographs when a compact file is important, but repeated saving can reduce quality.
- PNG suits sharp text, flat graphics and transparency, though photographic files may be larger.
- WebP can provide an efficient web image where the publishing system supports it.
- PDF is useful when the merged image belongs in a print-ready document.
Export at the intended pixel dimensions instead of taking a screenshot. Open the exported file separately and inspect it, because an editor preview may not reveal compression, transparency or colour changes introduced during export.
Before using the image, make one final pass:
- Confirm that neither panel is stretched or unintentionally cropped.
- Check the join, outer edges and masked areas at full size.
- Make sure labels are readable and do not cover important details.
- Compare brightness, colour, sharpness and noise across both images.
- Keep the editable master as well as the finished export.