For the other points, the other comments are quite spot on. Load speed: Umbrella's 2.5kb loads well under the rule-of-thumb size of a single packet of 14kb [1

For the other points, the other comments are quite spot on. Load speed: Umbrella's 2.5kb loads well under the rule-of-thumb size of a single packet of 14kb [1], so you have to do a single roundtrip for that [2]. In this 3rd party test [3] it takes ~200ms to load the whole Umbrella JS. JQuery weights ~30x more kb, so there are several packets sent, which makes it load in ~2s in the same test. Not to mention parsing and running all that extra JS. Heck, I regularly bundle my whole JS in a single file and thanks to Umbrella JS tiny size the whole thing weights well under 14kb. It loads in a snap. Edit: early send [1] https://tylercipriani.com/blog/2016/09/25/the-14kb-in-the-tcp-initial-window/ https://tylercipriani.com/blog/2016/09/25/the-14kb-in-the-tc... [2] Excluding the TLS trip, which is common anyway. [3] https://speakerdeck.com/mattclaffey/using-umbrella-js-for-modern-applications https://speakerdeck.com/mattclaffey/using-umbrella-js-for-mo...