In Switzerland, the same rules apply to online trading as to a purchase in a shop. Always read the seller's general terms and conditions (GTCs), because the law is rarely mandatory.
In the event of disputes with Swiss online traders, the E-commerce Ombudsman's Office can help you.
You should be especially careful when shopping online on foreign websites.
Tips for returns and exchanges
It is important that you can produce the receipt.
If possible, take or send the goods back in their original packaging.
Have the possibility of an exchange or return confirmed in writing on the sales receipt when you buy if you want to be sure.
It is not normally possible to exchange hygiene articles or reduced-price goods.