The basic way to merge images in Photoshop

The most straightforward method is to open one image as your base, then place the second image as a new layer on top of it. Start by opening your first image in Photoshop. Go to File > Open and select the image you want to use as your background or starting point.

Next, go to File > Open as Layers and select the second image. Photoshop will add it as a new layer in your Layers panel on the right side of the screen. You can now see both images stacked — the second one will appear on top. Use the Move tool (the cross with arrows) to drag the top image into position over the first one. If the top layer is too large or in the wrong spot, you can resize it by going to Edit > Free Transform and dragging the corners.

Key Takeaways

  • Open your base image first, then use File > Open as Layers to add additional images as separate layers rather than opening them in new windows.
  • The Move tool lets you position each layer where you want it, and Free Transform lets you resize or rotate layers to fit your composition.
  • Adjust layer opacity (the slider at the top of the Layers panel) to make overlapping images blend together or show through each other.
  • Use layer masks to hide parts of a layer without deleting them, which gives you more control over how images blend at their edges.
  • Flatten the image only after you are satisfied with the result — go to Image > Flatten Image to merge all layers into one permanent file.

Controlling how layers blend together

When you stack images, the top layer will completely cover the bottom one unless you change how it blends. The Opacity slider at the top of the Layers panel controls transparency — drag it left to make the top layer see-through so the image below shows through. This is useful if you want a watermark effect or a subtle overlay.

For more control, use the Blend Mode dropdown (it says "Normal" by default, right above the Opacity slider). Different blend modes combine the colors of the two layers in different ways. Multiply darkens the image, Screen lightens it, and Overlay increases contrast. Experiment with these to see which one looks right for your images.

Using layer masks to hide parts of an image

If you want one image to fade into another at the edges, or if you only want part of the top image to show, use a layer mask. Right-click the layer you want to mask in the Layers panel and select Add Layer Mask. Choose White (Full Opacity) to start with the entire layer visible.

Once the mask is added, you will see a white rectangle next to the layer thumbnail in the Layers panel. Select the mask (it should have a white border around it) and use the Paintbrush tool with black paint to hide parts of that layer. Paint with white to reveal parts again. This is non-destructive — you are not actually deleting anything, just hiding it, so you can always undo your mask strokes.

For a smooth fade between images, use a soft brush (lower the Hardness value in the brush settings) and paint along the edge where the two images meet. This creates a gradual transition instead of a hard line.

Resizing the canvas to fit all your images

If your images are different sizes, you may need to make the canvas larger so both fit without cutting anything off. Go to Image > Canvas Size. You will see the current width and height. Increase both numbers to give yourself more room. The anchor grid in the dialog shows where your current image sits — click a different anchor point if you want the extra space in a specific direction (for example, click the top-left corner if you want more space on the right and bottom).

After you expand the canvas, you can move your layers around to position them where you want them. The Move tool will let you drag layers onto the new empty canvas space.

Aligning layers precisely

If you need images to line up exactly — for example, if you are stitching together a panorama or combining photos that should match edge-to-edge — use the Align tools. Select the layers you want to align by holding Shift and clicking them in the Layers panel. Then go to Image > Align Layers and choose how you want them aligned (top edges, left edges, centered, and so on).

You can also use the Move tool with Auto-Align Layers for more advanced alignment. Go to Edit > Auto-Align Layers and Photoshop will try to match overlapping content and shift the layers into position automatically. This works well for panoramas or images with recognizable features that overlap.

Flattening your image when you are done

While you are working, keep your layers separate so you can edit each one independently. But once you are happy with how everything looks, you need to flatten the image to save it as a single file. Go to Image > Flatten Image. This merges all layers into one and removes any transparency.

Before you flatten, make sure you save your work as a Photoshop file (.psd) first — that format preserves all your layers so you can edit them later if you need to. Then flatten and export as .jpg, .png, or whatever format you need for sharing or printing.

Common mistakes and how to avoid them

The most common mistake is flattening too early. Once you flatten, you cannot separate the layers again, so always save a layered version first. Another mistake is forgetting to check which layer you have selected before you start editing — if you paint or transform on the wrong layer, you will be changing the wrong image. Look at the Layers panel to confirm the layer you want is highlighted in white.

A third mistake is making the canvas too small. If your images are larger than the canvas, parts will be cut off when you flatten. Always check the canvas size before you merge, and expand it if needed. Finally, do not rely on blend modes alone to make images look good together — they can help, but a layer mask and careful positioning usually give you better control over how the final image looks.

Frequently Asked Questions

Can I undo a flattened image?

Not directly — once you flatten, the layers are permanently merged. But if you have not closed the file, you can use Edit > Undo to go back a few steps. The best practice is to save a .psd version with all layers intact before you flatten, so you always have a backup to edit.

What is the difference between merging layers and flattening?

Merging combines selected layers into one while keeping other layers separate. Flattening merges everything into a single layer and removes transparency. Use merge when you want to combine just a few layers, and flatten only when you are completely done and ready to save the final image.

How do I make a smooth blend between two images?

Use a layer mask with a soft brush to create a gradual fade at the edges where the images meet. Lower the brush hardness to 0 percent for the softest transition, and paint slowly along the edge. You can also adjust opacity or use blend modes like Overlay to make the transition more subtle.

Can I merge images that are different sizes?

Yes. Expand your canvas size first to fit both images, then position each layer where you want it. You can also resize individual layers with Free Transform before positioning them. Photoshop will not automatically crop or shrink images to match — you control the size of each layer.

What file format should I save the final merged image in?

Save as .jpg for photos you plan to share online or email, .png if you need transparency or higher quality, and .psd if you want to keep editing the layers later. Always save the .psd version first before you flatten and export to other formats.