NextJS 15: React 19, Less Caching, Turbopack, Better Hydration Errors and MORE from Vercel Ship!

NextJS 15 Release Candidate 0 is out and it's got so much good stuff. Let's take a look feature by feature and try them out to see what's in store for us. React 19! Caching is off by default! Super fast builds with Turbopack! Hydration errors you can actually debug! And much more! Let's jump in!

👉 VS Code theme and font? Night Wolf [black] and Operator Mono
👉 Terminal Theme and font? oh-my-posh with powerlevel10k_rainbow and SpaceMono NF

00:00 Introduction
00:20 Trying Out NextJS 15
02:19 Now On React 19
04:13 Integrated React Compiler
06:51 Better Hydration Errors
07:56 Caching Off By Default
14:59 Per-Router Partial Pre-Rendering
15:24 Post-Route Callback with After
16:26 Build Updates

[nedimarabaci]

Instead of just reading release notes to us, you are demonstrating how it works! This is what makes you different from the others!

[flnnx]

Opting in for caching is much better than opting out by default. I'm so happy about these changes.

[Henrique]

Another great video, informative and well explained, thanks Jack!

[richierob]

Jack, small grammatical error on the pro landing page

“His YouTube channel hosts an entire free courses on React and TypeScript”

Thanks for all you do. Pretty sure you save me at least 100hrs of research a year.

[imakhlaqXD]

OMG finally no caching by default. I might cry 😭

[saharshg]

Crisp, to the point and no non-sense talk, thats why you are awesome!

[my_name_is_ahad]

Can't wait for next js 16 next month!

[phantom]

Appreciate your effort Jack! Your videos are so good and your explanation on point. Much love <3

[consoledoterror]

Thank you for the time and effort you put into this.
Really appreciate this.

[BuriTechVids]

15:26 - In the second sentense (or first two) is explained why we need after(). :-}

[isekaiguy]

10:58 You forgot to use html time tag. Video is awesome

[grugbrain]

in the end of the video, you smile then disappear, like a wizard 👻

[spidfair]

I like that caching becomes more of an opt-in feature. What I'd like to know is if request memoization is also affected by this change. Deduping fetch calls of a single request was great as it reduced prop-drilling. If caching is off by default, does that also mean that deduping on a single request is also off?

[marshall_grant]

I could see after() maybe as a tidy way to run 3rd party analytics that needs to also run on the server bypassing the 3rd party cookie apocalypse.

[cooldude]

Awesome content as always. But please tell me creating express mini services inside next projects is not about to become the norm! That's giving me the jeepy creepys. :O

[jordymaryns]

Just to clarify they do not think Turbopack is ready for production. Only the dev test pass.

[prashlovessamosa]

Thanks Mr Jack
I have one request can you make a video on SWR i have seen tweet from Rauch about client and server data fetching
Its quite good

[amanda.s.f]

Awesome video! May I ask what is your VSCode theme?

[mppor]

Hello, in next 14 there was a "next" options object on the fetch options which could be used to tell Next to cache the result for a specific amount of time. How to do that in next 15 ?

[abhishekvishwakarma]

Legends who are still on the next 12, for their production apps 😌
btw what pointers would you consider for someone who wants to upgrade to Next.js 13-14?

great video, informative !