Short answer — it depends on what you want, but for the biggest and most reliable fashion discounts in the Philippines:

• Zalora — best for branded fashion sales, app‑only promo codes, and bank/partner discounts (big seasonal events and first‑time app-user codes give large percentage or peso-off savings). (vouchers.johnarce.com)

• Shopee and Lazada — best for the largest variety of voucher types (sitewide vouchers, hourly flash coupons, seller discounts and huge cashback/coins offers), which often produce the lowest final prices on mass-market and mid‑range fashion during flash sales and mega sale days (e.g., 10.10, 11.11, 12.12). (coupons.Rappler.com)

• SHEIN — best for very low prices on fast‑fashion / trend pieces plus frequent stackable promo codes for extra peso discounts and app‑only vouchers (good if you want lots of cheap items rather than higher‑end brands). (Philstar.com)

Quick tips to get the “best” discount whichever site you use

• Shop during mega sales (10.10, 11.11, 12.12) and claim site/app vouchers before checkout. (coupons.Rappler.com)
• Use app‑only codes and first‑time buyer promos for extra % off on Zalora or SHEIN. (vouchers.johnarce.com)
• Stack payment or bank partner promos (cards, e‑wallets) and claim seller vouchers/coins/cashback on Shopee/Lazada. (coupons.Rappler.com)
• Compare final price (including shipping and return policies) — a marketplace voucher can make a non‑brand item cheaper than a branded “discount” on a retailer site.

If you want, tell me which type of clothing or brands you prefer (branded, fast‑fashion, shoes, designer) and I’ll recommend the single best store and current promo strategies for that category.