Overview
The canvas contains a faint dark-blue frame that marks the default area shown when ComfyUI opens. Keeping the main workflow inside that frame ensures that it appears immediately instead of being lost elsewhere on the large canvas.
A workflow can be saved as a JSON file with the Save control or Ctrl+S. It can be loaded with the Load control or Ctrl+O. Saving the graph preserves the nodes, values, and connections for later reuse.
Common editing and navigation controls include:
Ctrl+A: Select all nodes.
Delete or Backspace: Remove selected nodes.
Ctrl+Z: Undo.
Ctrl+Y: Redo.
Mouse drag on the canvas, or Spacebar plus mouse movement: Pan the canvas.
Mouse wheel: Zoom.
Ctrl plus individual clicks: Add nodes to a selection.
Ctrl plus drag: Draw a selection frame around multiple nodes.
Shift plus drag after selection: Move the selected group.
Ctrl+B: Bypass selected nodes. Bypassed nodes are shown in purple and do not run.
Node titles and colors can be changed from the right-click menu. Color-coding the negative prompt red, for example, makes it visually distinct. This becomes more valuable as the number of branches grows.
A Reroute node extends and redirects a connection without changing the data. It is useful when a direct line would pass behind another node or make the graph hard to read.
A built-in widget can be converted into an input. If CFG is converted from a KSampler widget to an input connector, a Primitive node can hold the value and feed it into the sampler. This separates configuration from execution and allows one value node to be positioned where it is easier to see or connect.
ComfyUI avoids unnecessary recomputation. If a workflow has already loaded a checkpoint and encoded unchanged prompts, changing the batch size or a KSampler value does not force every preceding node to run again. Execution starts from the earliest changed dependency. This behavior is visible when the active green highlight begins at the sampler rather than the checkpoint.
Generated ComfyUI images can retain workflow metadata. Dragging such an image onto the canvas can restore the graph used to create it, provided the metadata has not been removed. This makes shared images a practical way to inspect and learn another workflow.