In general, to migrate a design to a new version of KiCad, simply open the project with the new version, then open the schematic and PCB and save each file. More details about specific issues that may come up when migrating designs is covered in the Schematic Editor and PCB Editor chapters of the manual.

The symbol library format changed in KiCad 6.0. To continue editing symbol libraries made with a previous version of KiCad, these libraries need to be migrated to the new format. For details on this process, see the Schematic Editor chapter of the manual. Symbol libraries that have not been migrated can still be opened and used in read-only mode.

KiCad uses a number of terms that are fairly standard in the area of electronics design automation (EDA) software, and some that are more specific to KiCad. This section lists some of the most common terms used throughout KiCad’s documentation and user interface. Other terms that are more specific to a certain part of the KiCad workflow are defined later in this manual.

A schematic is a collection of one or more pages (sheets) of circuit schematic drawings. Each KiCad schematic file represents a single sheet.

A hierarchical schematic is a schematic consisting of multiple pages nested inside each other. KiCad supports hierarchical schematics, but there must be a single root sheet at the top of the hierarchy. Sheets within a hierarchy (other than the root sheet) may be used more than once, for example to create repeated copies of a subcircuit.

A symbol is a circuit element that can be placed on a schematic. Symbols can represent physical electrical components, such as a resistor or microcontroller, or non-physical concepts such as a power or ground rail. Symbols have pins which serve as the connection points that can be wired to each other in a schematic. For physical components, each pin corresponds to a distinct physical connection on the component (for example, a resistor symbol will have two pins, one for each terminal of the resistor). Symbols are stored in symbol libraries so they can be used in many schematics.

A netlist is a representation of a schematic that is used to convey information to another program. There are many netlist formats used by various EDA programs, and KiCad has its own netlist format that is used internally to pass information back and forth between the schematic and PCB editors. The netlist contains (among other things) all the information about which pins connect to each other, and what name should be given to each net, or set of connected pins. Netlists can be written to a netlist file, but in modern versions of KiCad, this is not necessary as part of the normal workflow.

A printed circuit board, or PCB, is a design document that represents the physical implementation of a schematic (or technically, a netlist). Each KiCad board file refers to a single PCB design. There is no official support for creating arrays or panels of PCBs within KiCad, although some community-created add-ons provide this functionality.

A footprint is a circuit element that can be placed on a PCB. Footprints often represent physical electrical components, but can also be used as a library of design elements (silkscreen logos, copper antennas and coils, etc.). Footprints can have pads which represent copper areas that are electrically-connected. The netlist will associate symbol pins with footprint pads.

A worksheet is a drawing template, typically containing a title block and frame, that is used as the template for schematic sheets and PCB drawings.

Plotting is the process of creating manufacturing outputs from a design. These outputs may include machine-readable formats such as Gerber files or pick-and-place listings, as well as human-readable formats such as PDF drawings.

Ngspice is a mixed-signal circuit simulator, originally based on Berkeley SPICE, that is integrated into KiCad’s schematic editor. By using symbols with attached SPICE models, you can run circuit simulations on KiCad schematics and plot the results graphically.

KiCad consists of a number of different software components, some of which are integrated together to facilitate the PCB design workflow, and some of which are standalone. In early versions of KiCad, there was very little integration between the software components. For example, the schematic editor (historically called Eeschema) and PCB editor (historically called PcbNew) were separate applications that had no direct link, and to create a PCB based on a schematic, users had to generate a netlist file in Eeschema and then read this netlist file in PcbNew. In modern versions of KiCad, the schematic and PCB editor are integrated into the KiCad project manager, and using netlist files is no longer required. Many tutorials still exist that refer to the old KiCad workflow of separate applications and netlist files, so be sure to check the version being used when looking at tutorials and other documentation.

The main KiCad components are usually started from the launcher buttons in the KiCad project manager window. These components include:

KiCad has a number of user interface behaviors that are common to all the different editor windows. Some of these behaviors are described in more detail in later chapters of this manual.

Objects can be selected by clicking on them or by dragging a selection window around them. Dragging from left to right will result in a selection of any items that are completely within the window. Dragging from right to left will result in a selection of any items that touch the window. Pressing certain modifier keys while clicking or dragging will change the selection behavior. These keys are platform-specific and are described in the Editing Options section of the Preferences dialog.

KiCad editors have the concept of a tool which can be thought of as a mode that the editor is in. The default tool is the selection tool, which means that clicking will select objects under the mouse cursor. There are also tools for placing new objects, inspecting existing objects, etc. The active tool is highlighted in the toolbar, and the name of the active tool is shown in the bottom right of the editor in the status bar. Pressing Esc always means "cancel" in KiCad: if a tool is in the middle of some action (for example, routing tracks), the first press of Esc will cancel that action. The next press of Esc will exit the tool complely, returning to the default selection tool. With the selection tool active, pressing Esc will clear the current selection, if one exists.