React Just Changed Forever

React Conf just happened, and it's been a wild ride. React 19 is out, but that's old news. We're here for something almost forgotten, something I've wanted for awhile.
The React Compiler is here. I'm so hyped.
SOURCES
playground.react.dev
react.dev/learn/react-compiler
• React Compiler: In-Dep...
github.com/facebook/react/pul...
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S/O Ph4seOn3 for the awesome edit 🙏

[@LongJourneys]

Don't worry, it's a JS framework, it'll change forever again next week

[@rohil3023]

🤣🤣🤣

[@sulavbaral9972]

So true lmao

[@thederpykrafter]

Facts

[@michacuranda5603]

Don't write it down. It's going to change next week.

[@sanglin9387]

😅😅😅 the reason now i make own spa js . enough is enough nightmare . enough re invent the wheel bugs

[@edumorangobolcombr]

We write TSX that becomes JSX that becomes JS that becomes "Compiled" JS that becomes ByteCode Porque, Maria

[@andreilucasgoncalves1416]

Devs just want more magic to be more productive

[@furycorp]

Meanwhile vanillajs gets more capable all the time :)

[@friendly__drone9352]

Is that a Pablo Francisco reference, my dude?

[@steftrando]

Because it's totally cross platform. Web code is actually useful code.

[@unkouwnfigure2746]

nothing stops you from building dekstop apps using C and QT if you want

[@caseyblair2341]

The best feature of React is it puts food on my family

[@TypingHazard]

I know how hard that is

[@SilvestreVivo]

compiled food probably

[@wlockuz4467]

And the only good feature

[@warrenarnold]

yea that thing kicks ass😅

[@MCroppered]

“Don’t write this down. It will all change next week”

[@OccupyMars-le9gy]

deep cut, love it

[@nathnaelwondisha6649]

lmaoo i was thinking the same

[@wlockuz4467]

Legendary

[@Senai]

Well played sir, well played.

[@darksideishere]

Kai

[@IoIxD]

Bro was so excited he made the video on the old DVD camcorder he found in the trash.

[@siriusmain1763]

💀

[@novnod]

Omg lmao

[@t3dotgg]

Fun fact, I actually had the camera on a mini tripod on a sideways trash can

[@alexanderhorner]

@@t3dotgg I don't think it's that bad

[@IoIxD]

@@alexanderhorner Well yeah it's viewable, it's more funny if anything.

[@speckdratz]

Watching solely to support the no-stupid-face-on-thumbnail approach 🙃

[@hi_im_julian_kirsch]

So, the compiler basically does what Svelte's compiler has been doing so far but for React? Neat

[@gageracer]

Also with the less line of code too. Svelte5next is 124.961 lines. Facebook devs are geniuses.

[@user-mx1ek4sl2m]

Yeah, now we got sveltes good practice on an actual good framework*

[@zuma206]

Not really at all, the svelte compiler converts it's vanilla js looking signal code into actual js signal code. react compiler produces the same code you could write normally, but with added optimisations that you'd usually add yourself using useMemo, memo, etc

[@gageracer]

@@zuma206 Yeah, it's a footGun remover. Not even a full compiler to optimize your code, at least yet.

[@Booyamakashi]

@@zuma206 "You would write normally" - Have you seen gibberish that compiler spits out?

[@malcolmdude]

Thanks for the update. Regarding Rust vs Go for the react compiler - Rust's algebraic types make it much easier to write parsers, ASTs and compilers compared to languages without these features.

[@elirane85]

memoizing is one of things that doesn't feel needed at first but then you find yourself with hundreds of components and everything grinds to a halt. I worked on a project where after around 5 years of development without using memoizing it became so sluggish that we had to skip two release windows just to add memoization to the hundreds if not thousands of components we had until it was usable again.

[@cristianosoleti489]

Funny how when Vue used a compiler (and still does), React devs used to say "I don't like compilers doing magic for me"

[@cocoscacao6102]

Eh... React devs always gravitated slowly to what other frameworks had already done years ago, while being completely oblivious about it and calling it innovation.

[@labilawal]

@@cocoscacao6102 So react is the Apple of frameworks?

[@Me-vc4sf]

React is like apple of javascript devs

[@oceantume]

One thing that made react stand out through all the shining new things that get released is that it virtually never forced anything and most improvements are optional and progressive additions you can do. The contrary is not necessarily a deal breaker for most, but when you have huge apps in production and you want upgrades without having to touch every component every few months it can definitely matter. You can still import react from a CDN today and use the non-jsx functions to use react on a single page of an old php app if you want.

[@JamesMikrut]

i cannot WAIT to see what this does for our UI performance

[@readywhen]

I love how much Payload is benefitting from the newest next and react changes! Glad you guys are putting in crazy effort to adapt so quickly

[@Booyamakashi]

Probably you wont notice, unless you start digging into performance tab. Unless you are a real customer with shitty pc, bloated OS, full ram and bad network.

[@HUEHUEUHEPony]

It will add 10 minutes to your build time

[@yoz0__]

Cannot wait to see how many new bugs it will introduce

[@zactron1997]

Considering how large the React Compiler codebase is already, I'm not surprised they want to rewrite in Rust straight away instead of something like Go. Rust's strict rules are one of the best ways to wrangle a massive codebase with that many contributors, especially in a context as important as "The Official React Compiler". Unit tests are just not enough to ensure reproducible results between commits. Throw in performance concerns and the possibility of using the React Compiler in the browser through WASM (Go's support in WASM is horrible compared to Rust) and it makes complete sense. Finally, this is a project they've already finished prototyping over the past 3 years. I doubt there's going to be any major changes to the fundamentals going forward. Whether you like it or hate it, the React Compiler is one of the prime examples of where Rust is a good fit for a project.

[@piaIy]

It's unfair to bring up Go's performance in Wasm in its current state when managed languages have to ship their own GC. Once WasmGC is stable, everyone will jump on languages that actually get shit done.

[@zactron1997]

@@piaIy I don't have any particular gripes with Go, if you like it then have at it! To say it's unfair to comment on Go's lack of performance on WASM is a bit silly though. I also find it silly that you're saying nothing gets done in Rust, in a comment on a video discussing things getting done in Rust. But to more directly address your point, WASM GC isn't enough to make Go viable on WASM. The fundamental issue is WASM is a highly resource constrained environment, so explicit management of resources is required to get even modest performance. Go is a good language, but this is an area where it is just a bad fit. It's like trying to run TypeScript on embedded.

[@binitrupakheti4246]

I remember a time when memoizing was seen like the devil, and people were like the overhead is much more than rerendering everything. It's funny to see how the times have changed and memoizing is the default now because turns out a check for the cache is almost always going to be faster than recalculating the value.

[@centner813]

First hand experience in delivering updates/news. Thanks man!

[@ElvenSpellmaker]

JavaScript changes so often Theo'll come back after the next talk and update saying it's been replaced with the next shiny thing already.

[@hobbit125]

React is not javascript.

[@RaZziaN1]

@@hobbit125 If it is js library it is js..

[@davidsiewert8649]

Most likely by Pheonix-Framework in Elixir/Erlang

[@matthewgiallourakis7645]

Or static hermes

[@SirusStarTV]

@@matthewgiallourakis7645 next in the line...dynamic herpes

[@farhanghazali4406]

Don't worry, its React, They will fix it again next version

[@orterves]

React spending all this time fixing issues of their own making.

[@Novacification]

Yeah, a framework so flawed that it needs its own compiler to avoid unintended side-effects during render.

[@ojolowoboluwatife9136]

Great video, I'm happy I could catch up

[@RockRespawn]

ngl Theo, liked this format of video a lot more than the heavily produced ones :)

[@sumitkarmakar-vc9bv]

I have one question , isnt our bundler be much more in size since the compiler is adding more code for caching?

[@matejukmar]

For me it feels the compiler is result of something being wrong in the core of react in the first place

[@offlercrocgod]

Indeed, if they used signals all this would be redundant.

[@chaos_monster]

Welcome on the darkside of using compiler. Signed the Angular Community for 8 years

[@colin_actually]

React changes forever every year. It's how we keep the javascript programmers too busy to work in other sectors.

[@warrenarnold]

Frontend developers are not programmer 😅😂😂😂😂

[@RolandAyala]

This biggest problem w/ React right now IMO is the it's too tied to Next/Vercel. I look forward to that problem getting fixed, and will happily stay on alt frameworks like Remix even if it means missing out on or needing to wait a long time for all the latest and greatest React features.

[@juxuanu]

Next.js with OpenNext works wonderfully in docker

[@WilliamWelsh]

hey roland great news you can actually use react without next or vercel just like theo did this entire video

[@thiagovieira8569]

Agajn?

[@Frazful]

My thoughts exactly

[@americanbagel]

I feel like react changes forever every other month

[@asemyamak3984]

Who moved on to SolidJs or Svelte for good?

[@fredbluntstoned]

Forever? That's weird! Usually react only changes for a short period! :o

[@NeilTheFisher]

Jack Herrington mentioned that memoization won't work for proxy state, specifically mentioning mobx. What do you think the best solution for that would be? I've been using valtio and that may affect me as well.

[@brennan123]

A compiler that doesn't work across file boundaries? WAT?!?!?

[@TimLouw]

More of just a parser or transpiler with some predefined find and replace properties😂

[@Leonhart_93]

@@TimLouw Even real compilers do that step.

[@TimLouw]

@@Leonhart_93 I'm aware they do that step but that's not what makes them proper compilers... It's a feature they generally handle but the fact that this compiler doesn't go across file boundaries is leaving a massive amount of optimization on the table.

[@theshermantanker7043]

That's literally every C or C++ compiler when you turn Link Time Optimization off. It's really more common than you think

[@coomservative]

TL;DR it’s Svelte now

[@joaofrancisco5781]

So it got better, F for SolidJs

[@DevlogBill]

Very exciting stuff. Since this is so new upon release date it would be nice if they left on Vite the new compile version and as well as the standard React project download version. I am assuming the compiler version will be excellent for certain use cases.

[@darkoplax7688]

it's hard to take Theo seriously when he does these 20min clickbait videos every other day about react changing

[@averagepickleballplayer]

…I mean it is changing though lol

[@ddomingo]

This is some cool stuff. I am glad that React is taking this direction.

[@thisandthatguy1156]

What are those menu icons after the recording one?

[@TimLouw]

I can't believe the React team took this many years to realise that they could deliver a much better developer experience and much better app performance by using a compiler. All the actually great frameworks started out with a compiler because they knew how key it was from the beginning.

[@geekofia]

React wasn't a framework, it was a library. Now it's becoming a framework.

[@TimLouw]

@@geekofia it's been touted as just a library but has over the years gained more and more of the typical features of a framework and it doesn't compete against libraries, it competes against frameworks. Just search React vs and all the results will be it getting compared to frameworks.

[@raphauy]

Very promising. Thank you!

[@wesleycoder]

It's awesome to see this problem being fixed after so long time. It's sad that this is a problem we created for ourselves. 😅

[@StephanHoyer]

If you mean fixing like fixing a broken leg with a band-aid, than you are right 😂

[@davidalejandrollanesbojorq63]

Hey, please can you tell me what Theme you are using in VS code?

[@underflowexception]

new week, more complexity!

[@andy_lamax]

Doesn't this affect bundle size though?

[@lumiannah]

My thoughts exactly. What about memory footprint as well?

[@sgguitarfan7]

Svelte had to exist, just so that react could become less shitty.

[@JuliusMalunhao]

I love your videos bro thanks for the info

[@ytuser6276]

How does it affect bundle size?

[@HUEHUEUHEPony]

Smaller, but don't look at build times

[@tungthanh4297]

Will webpack, vite are still working with such a new React compiler?

[@Leonhart_93]

Now this compiler might actually be an improvement that will make me add something new for the first time in the past 5 years.

[@ArturMullerDesign]

Congrats on making a video without a silly face thumbnail! It's great 🔥

[@kodekorp2064]

I remember when React first released and I had to choose between react or angularJS as the current two main techs lol

[@AivoPaas]

"React code" and "elegant" in the same sentence. Laughing in Vue.

[@CristianKirk]

React changed forever for 3 months.

[@mirzazplayz_rblx]

This guy yapp so much!!

[@toshobg]

I've never been so confused in my life

[@BarakaAndrew]

This is great, now we need static hermes on mobile then react is the only tool one needs for everything

[@ThatDereKid]

So basically rich harris was right

[@SilvestreVivo]

Basically he always is

[@StephanHoyer]

No. Both where wrong. Solution is a simpler, more predictable framework than react. Compiling makes things even more opaque. Try to debug in that code.

[@SilvestreVivo]

@@StephanHoyer I think Svelte 5 is pretty easy to debug. We don't need more React craziness. There are better alternatives.

[@StephanHoyer]

@SilvestreVivo I don't mean react. I find it aweful, too. But there are much simpler alternatives that don't need compilation at all. Like mithriljs.

[@SilvestreVivo]

@@StephanHoyer mithriljs? hahah I am migrating a project from mithriljs to Svelte because is extremely difficult to maintain. Let's be serious please.

[@senpaijs798]

Our belowed React Paster Theo.

[@kevinweir2499]

Someone please tell Theo there is an entire world of software out there besides JavaScript. A language by the way that was conceived and written in 10 days. Draw your own conclusions about the implications of that.

[@pinatacolada7986]

I'm at a conference but rather than enjoy myself, socialize, meet and talk to people and relax - I ran away to my secluded hotel room to talk, alone to myself. Find the bar, nerd.

[@dotthree7894]

Imagine trying to use a hammer, but each time you use it the handle is different

[@MasterF3]

Does this eliminate all unnecessary re-renders and the need for other techniques like building the component further up and passing it down as a prop?

[@cesarmartinez2207]

yes the react team went a different way with the compiler because instead of doing what signals already fixed they decided to hide the garbage behind this magic compiler

[@mag2XYZ]

So how much does this add to the bundle size?

[@Fidicirj]

No shit Theo, this format much much better that your normal videos. Not much opinions, enjoying the news, not much reactions. Hopefully you will keep it up.

[@jrreed47]

I ran out of breath for you watching this

[@user-xj5gz7ln3q]

Wait until next week... It'll change again. :D

[@crism8868]

"Don't bother writing any of this down is going to change next week" - Programmers are also human

[@ParanoidxProd]

Sexy tan lines 👀 Now that’s the T3 Skater Boy we all know and love!

[@Rtzoor]

funny seeing you with natural lighting then KRAZAM drops The Solar Sermon

[@patcoston]

6:46 I found a bug in your wording. Check the spelling of etcetera, then listen to yourself say it. I used to say it that way until one day I went to write etc. but instead I wrote ect., then I thought, that can't be right. I figured out the glitch in my matrix, and uploaded a patch.

[@RasmusSchultz]

what about output file size? compiled output looks substantially more complex. I also wonder how this affects debugging. the addition of a compiler radically changes React code from something where you can easily imagine what the output looks like - the standard React JSX transform is so trivial, so easy to understand and explain. we've sort of lost that. I'm still unsure why I should be more excited about this than about something like Solid, which was designed and built for the kind of performance and scalability React is fighting for... but did so with design rather than by layering more complexity on top of complexity. at the end of the day, doesn't all of this added complexity exist primarily to correct inherent design problems that React itself created?

[@fadfooood]

React compiler only works with react 19? If yes, then how do we use it on existing projects?

[@hodev632]

If it leads to the removal of unused code in react dom, so we don't download 140 kb library, it would be great. That's the point of using build tools . Like what we have in Svelte other than that, it's a nice update

[@nro337]

Huge news!

[@Woeden]

>Compiler built in rust. Of course it is. Why isnt Rust in the browsers already? Javascript is slowing us so much.

[@MichaelLazarski]

React is Svelte now

[@paxdriver]

Theo, you're amazing

[@neizvestniydrug]

Hype! Hype! Hype!!🎉🎉🎉😂😂😂

[@pastuh]

sometimes I think... need go back to art, one simple pencil which never changes

[@gabbeeto]

well your keyboard never changes and the techniques you're going to use in art are going to be different overtime

[@jak3legacy]

The necessity of a compiler at such an abstract level has convinced me that React was a pioneer in component-ized architecture, but that React itself, particularly the rendering lifecycle and surrounding architecture, is not it. React's "children" frameworks and architectures built around signals and other reactivity systems will be the future. Just not sure how far into the future. React has effectively gone from a rendering library inside of a programming language, to a scripting language (as it is written by developers).

[@snowwsquire]

The 14 inch mbp aspect ratio feels very weird but i kinda like it

[@Kaczucha888]

This sounds like it is going to be memory hungry! React VDOM is just a bad abstraction

[@yungouda]

We need to make Theo implement a compiler in Go and in Rust.

[@dmullen1994]

ur hair looks good at this length

[@rob011]

That’s not length, it’s 1-based indexing

[@habong17359]

Tomorrow: React Just Changed Forever and Ever

[@habong17359]

Next week: Next.js Just Changed Web Development

[@habong17359]

Next month: React Just Changed Forever, But This Time For Real

[@habong17359]

2 Month later: Next.js Just Changed Everything, But This Time "EVERYTHING"

[@habong17359]

3 Month later: React Got Rid of `use()`

[@habong17359]

4 Month later: Next.js Revives `use()` and Changes The Fundamental Thinking of Web Development.

[@voltflake]

0 days since react changed forever

[@sashogs]

Time to move to solid?

[@PaulBunkey]

Just now noticed... Theo is somewhat similar to Freddie Mercury. More so than Rami Malek... Just stop at 0:15 and imagine him with short hair 😄

[@williamliu796]

is this something that is being built into ‘next dev’?

[@rapzid3536]

MobX and chill.

[@prestigealanazi2993]

I was about to learn svelte wat

[@prestigealanazi2993]

I thought that will change a little of the syntax or coding simplicity , but seems no , therefore I would still learn svelte kit and capacitor js ( as it seems the best easiest way ) for the backend tho I think I will mix between asp , node and mongodb

[@richardantao3249]

Hot take: every piece of software changes forever after every release

[@osbyrne]

here before @malix ????

[@yashjadhav6838]

Will this also affect react Native

[@emaayan]

a pull request with 1900 commits, grab a snack the code review may take a while...

[@mr.random8447]

Team Svelte

[@ajar1000]

React never stops changing lol

[@____---__________--------_____]

it changes forever with each announcement

[@tyu3456]

People say this but at the same time... React has been on v18 for years

[@oemeraran8183]

Manual memoization (performance in general) and forwardRef were really always my biggest reasons to switch to other frameworks. With both of these changes, I dont see any reason to switch anymore. I think React has the best mental model now, making the code easy to understand and reason about, without having to know the internals. I am especially talking about DX not about the complexity of the internal code. Even though I love solid, i much rather use spread operators instead of helper functions like "mergeProps". It just feels more natural to use. Also using variables instead of calling function to get the reactive state. And don't let me start with Vue magic and ".value" insanity. It's so odd to retain reactivity. Same with Svelte. I don't like the crazy magic and custom file extentions to make these frameworks work. Either tsx or ts. Solid was the only real alternative, but with these changes and the existing insane ecosystem, I really don't see a reason to leave react behind. We have to understand and also appreciate, that react was ome of the first and they need the time to fix core issues from framework level now, which they are always trying to do.

[@nephis_2006]

fyi you dont need .vue to have a vue project

[@oemeraran8183]

@@nephis_2006 i know you can use tsx, but it's not the default. I tried it once and the resources were lacking, as every blog post was about SFC. If you opt-out of default behaviour you always have different kind of problems. Also not every team member would want to use tsx.

[@lazarpro3030]

so they were the ones lagging github

[@bluecup25]

To be honest, IG in the web moves like s**t and makes my browser run out of RAM if I open several tabs, which is quite an incredible feat for an online image / short video viewer.

[@JenuelDev]

wait, is this already in vuejs?

[@Caldaron]

theo got new teeth?

[@gnoyl]

Oh wow another fundamental change that deprecates 6 month old code! Love to see it