Manage layers and layer groups

As you add layers or layer groups to an image, it’s helpful to give them names that reflect their content. Descriptive names make layers easy to identify in the Layers panel.

• Double-click the layer name or group name in the Layers panel and enter a new name. Press Enter (Windows) or Return (macOS).
  

• Select the layer/group and then follow these steps:
  • Choose Layer > Rename Layer or Layer > Rename Group.
  • Enter a new name for the layer/group in the Layers panel.
  • Press Enter (Windows) or Return (macOS).
    

Delete layers

Deleting the layers you no longer need reduces the size of your image file. To quickly delete empty layers, choose File > Scripts > Delete All Empty Layers.

To delete layers or layer groups having edits, follow the steps below:

Export layers

You can export all layers or visible layers to separate files.

Assign colors to layers

Color coding layers and groups helps you locate related layers in the Layers panel. Simply right-click the layer or group and select a color.

Rasterize layers

You cannot use the painting tools or filters on layers that contain vector data (such as type layers, shape layers, vector masks, or Smart Objects) and generated data (such as fill layers). However, you can rasterize these layers to convert their contents into a flat, raster image.

Once your layer is rasterized, you cannot edit them earlier because they are now converted to pixel-based layers. It's recommended to duplicate your layer and apply rasterization so that you can always go back to the original if necessary. To rasterize a vector layer or a Smart object, you can simply select a vector-based layer or a Smart Object and then choose Layer > Rasterize > Layer or Layer > Rasterize > All Layers to rasterize all layers in your document.

Rasterizes the type on a type layer. It does not rasterize any other vector data on the layer.

Rasterizes a shape layer.

Rasterizes the fill of a shape layer, leaving the vector mask.

Rasterizes the vector mask on a layer, turning it into a layer mask.

Converts a Smart Object into a raster layer.

Rasterizes the current video frame to an image layer.

Rasterizes the current view of 3D data into a flat raster layer.

Rasterizes all vector data on the selected layers.

Rasterizes all layers that contain vector and generated data.

Read the full article. Start with selecting any of these topics to learn more:

Merge layers

When you have finalized the content of layers, you can merge them to reduce the size of your image files. When you merge layers, the data on the top layers replaces any data it overlaps on the lower layers. The intersection of all transparent areas in the merged layers remains transparent.

When you save a merged document, you cannot revert back to the unmerged state; the layers are permanently merged.

With Photoshop, you can apply any of the following merge operations on layers:

• Merge down: To merge two adjacent visible layers where the bottom layer is a pixel layer, select the top layer in the Layers panel and then choose Layer > Merge Down, or choose Merge Down from the Layers panel’s menu, or press Cmd+E (macOS)/ Ctrl+E (Windows). Following this, Photoshop merges all top layers into the bottom pixel layer. You'll always need a pixel layer at the bottom of your layers to use the merge commands. 
• Merge visible: To simply merge a selected few layers in your document, you can hide the layers you don’t want to combine and select a pixel layer as your base. Then, go to Layer > Merge Visible, or choose Merge Visible from the Layers panel’s menu, or press Shift+Cmd+E (macOS)/ Shift+Ctrl+E (Windows).
• Merge active: Select all the layers you want to merge whether they are vector or pixel layers, and go to Layer > Merge Layers, or choose Merge Layers from the Layers panel’s menu, or press Cmd+E (macOS)/ Ctrl+E (Windows).
• Merge linked: To merge linked layers together, select the linked layers by choosing Layer > Select Linked Layers, or choosing Select Linked Layers from the Layers panel’s menu, and then opting for the steps listed for merging active layers above.

Merge layers in a clipping mask

For more information on clipping masks, see Mask layers with clipping masks.

Stamp multiple layers or linked layers

In addition to merging layers, you can also stamp them. Stamping allows you to merge the contents of more than one layer into a target layer while leaving the other layers intact. When you stamp multiple selected layers or linked layers, Photoshop creates a new layer containing the merged content.

You can prefer to use stamping when you want to edit multiple layers with the same tools but only one layer at a time. Stamping combines the selected layers into a new layer, leaving the original layers as is.

You can work with the following stamping options:

• Stamp active layers: Select the layers that you want to stamp and then press Opt+Cmd+E (macOS)/ Alt+Ctrl+E (Windows).
• Stamp visible: You can disable the layers that you do not wish to stamp by turning off their visibility in the Layers panel and then pressing Shift+Opt+Cmd+E (macOS)/ Shift+Alt+Ctrl+E (Windows). Also, you can hold Opt (macOS)/ Alt (Windows) as you select Merge Visible from the Layers panel’s menu to merge them into a new layer.

Flatten layers

Flattening reduces file size by merging all visible layers into the background and discarding hidden layers. Any transparent areas that remain are filled with white. When you save a flattened image, you cannot revert to the unflattened state as the layers get permanently merged.

You can work with any of the following flattening options:

• Flatten Image: To flatten your entire Photoshop file, go to Layer > Flatten Image or select Flatten Image from the Layers panel’s menu.
• Flatten All Layer Effects: To flatten only the layer styles instead of the entire image file, select File > Scripts > Flatten All Layer Effects. This makes the layer styles combine with the layer they are attached to. On applying any layer styles to vector layers like Type or Shape layers, the layer styles will get rasterized.
• Flatten All Masks: To permanently apply masks to their associated layers, select File > Scripts > Flatten All Masks.

The image on the left shows the Layers panel (with three layers) and file size before flattening. The image on the right shows the Layers panel after flattening.