"Would" can be construed as a subjunctive form which express inherent doubt. So your first sentence connotes that you may or may not do the action contemplated. The second sentence, "will" is indicative future, and specifies what will happen. In other words, there is little doubt that the action will be realized. And since you question the finer points of these verbs, why not take the opportunity to clean up your orthography. Poor orthography always reflects negatively on the author, even more so than semantics. This is because orthography is taught from age 8 up, so it is considered a fundamental skill. Whereas in some cases, the semantics you question can rise to the university level. "I thought I would keep my closest family members, and get rid of the ones I don't really talk to, like people I met for one or two dates." [Cleaned orthography, use more conventional phrasing]

Hi 哈里, A basic conceptual difference between these two modal verbs is: 1. Will: for describing a future event that will happen 2. Would: Based on a time in the past and you imagine a future event (still in the past) You will notice that you used "thought". This means that you were thinking of the criteria you would apply to discard or keep your Facebook friends. You started thinking of your criteria at a point in the past and the keeping or discarding process would take place at a future time (still in the past). In contrast, you can write: " I think I WILL consolidate my contact list now. / I think I WILL consolidate my contact list this weekend. Hope this helps. Cheers, Lance

Would - is conditional. That is, it is not 100% confirmed that you will proceed to do something. Will - expresses something that you are certain about. The first option is correct. The second one is not, as there is a tense disagreement ("thought" should be used in conjunction with another verb in the past tense such as "would"). In order to make the second option correct, it would have to be "I think I will..."