With the rapid growth of Wi-Fi-enabled devices and the growing need for faster data speeds, compact and efficient antenna designs have become a critical requirement. This study demonstrates the creation, simulation, and evaluation of a dual-band slot-loaded microstrip patch that is well-suited for Wi-Fi applications. The proposed antenna functions at 2.48 GHz and 5.78 GHz, covering the primary IEEE 802.11 WLAN frequency bands. A The rectangular patch has an engraved slot, and an additional slot is integrated into the grounding plane to improve dual-band capabilities. The antenna is fabricated on an FR-4 worksheet with measurements of 20 mm × 24 mm × 1.6 mm. The same electrical (relative permittivity) of the substrate, denoted as εr, is taken as 4.4 for FR4 in this design and supplied by a miniature line. Simulations conducted in CST Studio Suite 2023 demonstrate bandwidths of 102.69 MHz and 216.83 MHz, with corresponding return losses of − 32.94 dB and − 37.72 dB. The antenna maintains a stable omnidirectional radiation pattern across both bands. Comparative evaluations highlight its advantages in size, efficiency, and ease of integration for practical Wi-Fi system deployments.