Laboratory-based gait analysis using motion capture and force plates remains the gold standard for quantifying ground reaction forces (GRFs) and temporal gait parameters. However, its high cost and limited accessibility restrict routine clinical use. Wearable smart insoles offer a portable alternative, yet require rigorous validation before clinical adoption. This study evaluates the clinical and technical validity of the SuraSole® smart insole, a low-cost pressure sensor–embedded insole, by comparing its GRF and temporal gait measurements with those obtained from a laboratory force plate and 3D motion capture system. Twenty healthy adults completed five walking trials while wearing standardized footwear equipped with SuraSole insoles, with simultaneous force plate and motion capture data collection. Agreement between systems was assessed using Bland–Altman plots and intraclass correlation coefficients (ICCs). SuraSole demonstrated excellent agreement with force plates for GRF across weight acceptance, mid-stance, and push-off (ICCs 0.97–0.99), with mean differences of 15.93 ± 45.90 N, 2.38 ± 23.98 N, and 8.64 ± 40.45 N, respectively. Temporal parameters showed moderate to good reliability (ICCs 0.62–0.81), with limitations likely related to the insole's 20 Hz sampling rate. These findings indicate that SuraSole provides reliable GRF measurement and acceptable portable gait assessment, supporting its potential for use in clinical practice, rehabilitation, and community health monitoring. Future hardware improvements, particularly higher sampling frequency, may enhance temporal accuracy.