Siam Square and The Platinum Fashion Mall are popular shopping places in Bangkok. If you do not have time to visit both places and want to choose the better one, you have come to the right place. In this post, I would not give you a concrete answer, but I will compare them in several aspects. Then, you just choose the one you like. Hope it helps.
Siam Square is an outdoor area that consists of several alleys or sois. Each alley is full with shops and most shops have their own air conditioners. So, it is not that hot to wander around. Platinum Mall is an indoor shopping complex consisting of two buildings.
Siam Square is a quite big area, while Platinum Mall has 3 zones within 2 buildings and there is a bridge connecting the buildings. It is difficult to visit all shops in both places in one day.
Siam Square is popular for trendy stuffs. You can find several products and services such as books, CDs, clothing, shoes, handbags, accessories, restaurants, coffee cafés, tutoring schools. Besides, it also connects with several shopping malls such as Siam Square One, Siam Paragon, and Siam Center. For Platinum Mall, it is a shopping place that specializes in fashion items such as clothing and accessories.
If you want to buy cheap products or plan to buy in bulk, Platinum Fashion Mall should suit you more.
Most of the shops in these two shopping places accept bargaining. However, some shops at Siam Square might not accept bargaining. No worry about this. Just ask the sellers politely.
It depends on the shops. Most shops are open daily.
Siam Square can be reached by BTS Skytrain. Just get off at Siam Station.
For Platinam Mall, it does not connect with any rapid transportation systems. You can take BTS Skytrain to either Chidlom Station or Ratchathewi Station. Then, take a short walk.
Update: May 2017 Recently we have a new skywalk connecting between Chidlom BTS Station and Platinum Mall. So it is more convenient ( You can read more detail here)
You can read my review of Siam Square here and The Platinum Fashion Mall here.