: The current market leader for shoe sales in the U.S..

Nike Fit , a computer vision tool that scans your foot's exact dimensions (length, width, and volume) to recommend a precise size for specific shoe models.

Curated lists and a robust VIP program that provides frequent discounts and free shipping on all orders. ASOS : Best for fast fashion and trend-focused styles.

: Excellent for finding deals and designer styles at lower price points.

Their 90-day "Perfect Fit Promise" allows VIP members to actually run in the shoes for three months and still return them if they aren't right. Nike : Best for direct-from-brand athletic performance gear.

: The premier choice for athletic and running footwear.

Virtual Try-On technology for select styles and the Amazon Warehouse section, which offers deep discounts on open-box or lightly used footwear.