Being able to consume media without the fluff of sponsors, being reminded to sub, intros and outros built into the video makes this a special extension, especially when you can do it on normal videos and music videos. Not only is this a crowdsourced extension that everyone contributes to, but you can too! If you see a video not have the sponsorblock added, please contribute if it needs it!
It's fantastic at what it does and I cannot recommend it any further than the highest praise. Make sure to check out this developer's work. Very smart, very helpful and very user-friendly!

10 months later:
It seems I cannot mark a full video as "Unpaid/Self Promotion" without it going away upon refresh. This extension was phenomenal before, it can be again.

I can't watch Youtube videos without this extension alongside Ublock Origin for blocking Youtube ads for free and Return YouTube Dislike for identifying bad videos.

Beautiful extension, thank you Ajay and the community behind submitting data.

Inadequate developer.

This extension helped me reclaim many hours of my life.

YouTube is unusable without it.

Works great for sponsors, tangents, unpaid promos, and the highlight feature is such a timesaver

I don't know if YouTube has done something on their end, or something went REALLY wrong with the latest update, but if I have SponsorBlock enabled, YouTube will now refuse to load anything but my subscriptions page.
It's also become exceptionally hit or miss with catching sponsored content, even when I manually tag stuff.

Edit: I re-enabled it with all other addons turned off, and it still did this, and it it was only when I turned it off when YouTube would load anything but my subscriptions page as of 9-8-2025.

wish i could leave zero stars. did nothing at all, i can only assume at this point the five star reviews are bots

i'm so thankful for this, it's such a life-changer. thank you so so so much

Works great to skip sponsorship segments in YouTube videos