Circuit Builder

Describe combinators and wires as text, paste a complete circuit into the game

Browse by category or search; selecting opens a preview with the wiring diagram before inserting.
Start typing a signal, item or fluid name and pick from the dropdown with Enter or Tab. Esc closes it. Ctrl+K describes the word at the caret - or open the full .
Blueprint string
  • Ctrl+Enter generates; Ctrl+B copies the blueprint. Hover a word, or put the caret on it and press Ctrl+K, for a hint. The lists every block.
  • Ctrl+F finds, Ctrl+H replaces (whole-word toggle renames a signal safely). Ctrl+/ comments, Alt+↑/↓ moves lines, Ctrl+D duplicates, Ctrl+Alt+↑/↓ jumps blocks, Shift+Alt+F (or the Format button) formats.
  • Import with the blueprint import button (or Ctrl+V after copying in game).
  • Paste an existing combinator blueprint above to edit it as text.
  • Combinators paste in wire order, wrapping into a compact grid; wide circuits stack into rows instead of one long line.
  • Wires are undirected; .in and .out pick the combinator connector.
  • A wire spanning more than 9 tiles in the row gets a warning - relay it in game.
  • ELSE outputs and SELECT TIME need Factorio 2.1; everything else works on 2.0 too.
Wiring diagram
Simulation
CONST blocks feed the inputs; outputs appear one tick after their inputs change. RANDOM uses a fixed seed. Stack size, rocket capacity and quality ops are not simulated.
What this circuit does
Layout
Tile-true placement of the generated blueprint: AT pins, relay poles, wire spans (red/green; dashed = past the 9-tile reach).