Overlay images, one picture over another.

To overlay an image is to place one picture on top of another and decide how the two mix. This tool lets you add as many overlay pictures as you want over a base picture, move and resize each one with the pointer or the keyboard, turn and flip it, set its opacity and choose one of twelve blend modes. The result is saved at the base picture's own size as a PNG, JPG or WebP. Typical uses are a logo or watermark, a texture over a photo, a sticker, a frame, a double exposure and a light leak.

How to overlay a picture

1. Drop the base picture on the box, or paste one with Command V or Ctrl V.
2. Press Add an overlay picture, or drop one or more pictures onto the workspace. A PNG with a see-through background keeps its see-through parts.
3. Drag the overlay to move it. Drag a corner square to resize it and the round handle to turn it. Or use the arrow keys to move it, plus and minus to resize it, and comma and full stop to turn it. Hold Shift to take bigger steps.
4. Under This layer, set Opacity and Blend mode. Press a square in the Position grid to snap the layer to a corner, an edge or the middle.
5. Press Download the picture. Cmd or Ctrl Z undoes the last change.

What the blend modes do

Normal puts the overlay on top, and Opacity decides how much of the base shows through. The other modes mix the numbers of each pixel. The table uses one grey base pixel at 200 and one grey overlay pixel at 128, on a scale where 0 is black and 255 is white, at 100% opacity.

Multiply is the one to use for a texture, a stamp or a shadow, because white in the overlay leaves the base untouched. Screen is the opposite: black in the overlay leaves the base untouched, so it suits light leaks, smoke, stars and fireworks photographed on black. Overlay, Soft light and Hard light add contrast and colour from the top picture and work well for grain and paper textures. Colour dodge and Colour burn are stronger versions of Screen and Multiply. Exclusion is a softer Difference.

Overlay tips for common jobs

• A logo or watermark: use a PNG logo with a see-through background, set it small, drop Opacity to 40 to 60, and press a corner in the Position grid.
• A double exposure: put a landscape over a portrait, use Screen or Lighten, and lower Opacity until both read well.
• A texture: add the texture, press Cover the base so it fills the picture, and try Multiply, Overlay or Soft light at 30 to 70.
• A frame: add a PNG frame and press Fit the width.

Size, quality and layers

The screen shows a copy of the base picture at up to 1400 pixels, so dragging stays smooth. Every position and size is kept in the base picture's own pixels, and the download is drawn again from the original files. A 4000 x 3000 base gives a 4000 x 3000 result. The layer list shows the top layer first. Forward and Backward change the order, the eye hides a layer without deleting it, and Duplicate makes a copy a little to the side. Colours are worked on and saved as sRGB, and a picture with a camera orientation is turned upright first.

Common problems

• The overlay has a white box around it. The picture has no see-through background. Use a PNG with transparency, or try Multiply so white disappears.
• The edges look soft. The overlay is small and has been enlarged. Start with a bigger picture.
• The overlay will not move. Another layer may be on top of it. Pick it in the layer list.
• A JPG shows no see-through. JPG cannot hold transparency, so empty parts turn white. Save a PNG or WebP.

To put plain text on a photo, use add text to photo, and to put a mark on many pictures at once, try watermark image. To make a collage of several pictures side by side, use the collage maker.