I’m just browsing.我只是隨便看看
I’m just looking. 我只是隨便看看
thumb through sth 隨便翻一翻

去逛商店,店員上前"May I halp you?"
不買就說"I’m just browsing."店員就不會緊迫盯人了

to turn the pages of a book, magazine, or a document quickly and only read small parts of it:

例如
"Have you read the report?" "Well, I thumbed through it quickly on the train."

browse (LOOK) 瀏覽
to look through a book or magazine without reading everything, or to walk around a shop looking at several items without intending to buy any of them:

例如
I was browsing through fashion magazines to find a new hairstyle.
"Are you looking for anything in particular, madam?" "No, I’m just browsing."