Adobe Photoshop costs too much and tools like GIMP don’t feel familiar enough for me to stay in flow. That’s why I built Compositor.

The goal was to create a full-featured image editor that is completely free and open source. I used to use Photoshop for compositing and post-processing, so Compositor is built around that workflow - with the tools needed to create a pixel-perfect final image.

Because it’s open source, you can download the Xcode project and add, remove, or modify any feature to fit your workflow.

Get Compositor from robbietilton.com/compositor, or download the latest release directly from GitHub Releases.

brew install --cask robbietilton-compositor

• Layers and folders, with opacity and Photoshop's full set of blend modes in its order — a folder's opacity dims everything inside it
• Layer masks: paint, fill, invert, blur and feather them anywhere on the canvas, past the layer's own pixels; link or unlink them to transform a mask on its own
• Clipping masks and folder masks
• Adjustment layers: Hue/Saturation, Levels, Curves, Exposure, Gradient Map, Grain, Black & White, Color Balance, Invert, Gaussian Blur, Motion Blur and Noise
• Layer effects: Stroke, Drop Shadow, Color Overlay, Inner Shadow, Outer Glow and Inner Glow, rendered on the GPU and editable at any time
• Merge Down, Merge Layers and Merge Group (⌘E)
• Duplicate, rename inline, reorder and nest by drag and drop; Option-drag to duplicate; a right-click menu in the Layers panel
• Copy and paste whole layers and folders (⌘C/⌘V with no selection), within a project or between projects, or drag them between projects

• Non-destructive move, scale, rotate and flip — images keep their full resolution however small you make them
• Free distort (⌘-drag a handle), with Shift to lock to an axis
• Transform several layers, or a whole folder, together
• Snapping to canvas and layer edges and centers, with guides
• Exact values for position, size, scale and angle, stepped with the arrow keys
• Flip Layer and Flip Canvas, horizontal and vertical

• Rectangle and Ellipse Marquee, Freehand and Polygonal Lasso, and the Magic tool — Wand selects by color, Object traces whatever you click (Tab switches)
• Select Subject, and Expand, Contract and Feather on any selection
• Add to and subtract from selections, move the outline, or move and duplicate the pixels inside
• Load a layer's pixels or a mask as a selection
• Content-Aware Fill, which can also extend an image past its edges

• Brush with size, hardness, opacity and smoothing, in Paint or Erase mode (B and E), and Shift for straight lines
• Spot Healing Brush (content-aware)
• Clone Stamp, aligned or not, sampling one layer or all of them
• Blur tool, on pixels or masks
• Gradient tool and Shape tool (rectangles, rounded rectangles, ellipses and lines), which stay editable rather than being rasterized
• Type tool (T): inline multiline editing in draggable, resizable paragraph boxes; font, size, color, alignment and spacing in the tool header; transform text and use it as a clipping mask
• Eyedropper and a full color picker

• Camera Raw filter: light, color, curves, color mixer, color grading, detail, optics and geometry, in a panel beside the canvas
• Levels (with Auto), Curves, Hue/Saturation, Exposure, Gradient Map, Grain, Black & White, Color Balance and Invert
• Gaussian Blur and Motion Blur that spread past a layer's edges
• Add Noise, Vignette, Bloom / Glow, Tonal Contrast, Lens Correction and Remove Background
• Live previews, limited to the selection when there is one

• Multiple projects in tabs
• Rulers (⌘R), guides dragged from them, a layout grid with adjustable spacing and subdivisions, and Snap To for guides, grid, layers and document bounds
• Crop with snapping, ratios including 3:4 and 9:16, and Option for symmetric cropping; with a selection, the crop starts at it
• Canvas Size, Image Size and Trim
• Sharp high-quality downsampling when zoomed out, and a pixel grid when zoomed in
• Import JPEG, PNG, HEIC, TIFF, SVG, camera RAW (with a develop step first) and Photoshop PSD and PSB (8-bit RGB; not CMYK). Photoshop folders, masks, blend modes, fill rectangles/ellipses, and simple horizontal text stay editable; other vectors and vertical text become pixels. A conversion report is shown before anything is applied.
• Large documents: the memory budget scales with your Mac, and a Photoshop file too big to open has its layers cropped to the canvas instead
• Export JPEG with a live preview (⇧⌥⌘S); Copy Merged
• Keep working while a project saves
• Photoshop-style keyboard shortcuts throughout, remappable in Edit > Keyboard Shortcuts
• Drag a number's label to scrub its value, as in Photoshop
• Automatic updates, signed and notarized

• AI agents and scripts can build and edit projects directly: a .comp is a folder of PNG layers and a manifest, and an open project updates live as it's written. See Writing Compositor projects

• macOS 26.0 or later on a Mac with Apple silicon
• Xcode 26 or later (to build from source)

Open Compositor.xcodeproj and run the Compositor scheme.

scripts/release.sh builds a Release version, signs it with Developer ID, notarizes and staples it, and packages it into dist/Compositor-<version>.dmg.

It needs, all kept outside this repository:

• a Developer ID Application certificate in the login keychain
• notarization credentials saved with xcrun notarytool store-credentials "compositor-notary" …
• create-dmg (brew install create-dmg)

MIT — see LICENSE.