An image forming apparatus, including: a photoconductor; an exposing device configured to expose the photoconductor and form an electrostatic latent image on the photoconductor; a developing device including a developing roller configured to form a developer image on the photoconductor; a transfer device configured to transfer the developer image to a sheet; a developer storage storing developer; a supplier configured to supply the developer from the developer storage to the developing device; a sheet feeder configured to convey the sheet toward the transfer device; a sheet sensor configured to detect the sheet conveyed toward the transfer device; and a controller, wherein the controller is configured to start a supplying process of supplying, by the supplier, the developer to the developing device before formation of the electrostatic latent image corresponding to the sheet is started, based on a signal indicating that the sheet sensor has detected the sheet.