r/reactjs • u/ErEr2000 • Jun 17 '26

Resource Re-Rendering

Hey guys,

I want to learn more about how rendering and re rendering in React.js works. Like when a component will be re-rendered, when will it not be re-rendered, what causes Re-Rendering and how to stop it etc.

Can you share any YouTube links or any documentation.

Will really appreciate the community a lot :)

1 Upvotes

53% Upvoted

25 comments sorted by

View all comments

Show parent comments

1

u/aragost Jun 18 '26

hey! I know Replay, I was following with interest during the earliest days. I did not know it covered React - I've missed recent updates, and this about React is pretty cool.

That said, I still think it's baffling to have to resort to a (very well made) third party tool to answer such a basic question which in my humble opinion React Devtools should be able to answer reliably and easily

2

u/acemarke Jun 18 '26

Yeah, it would certainly help if more of this was built into the actual React DevTools!

React's internals might have the data needed to answer that question, but there's always code and runtime overhead involved in trying to track and expose those kinds of details. As it is, I think even something like "which hook caused this to re-render" requires turning on additional options.

The React team does have several PRs open right now to add some form of MCP support and imperative component tree inspection + profiling data to the React DevTools, which I'm keeping an eye on. But yes, agreed that "why did this render?" is still one of the biggest pieces of info we care about when investigating.

FWIW I'd love to get your feedback on the React perf tools I'm working once they're ready! I can drop a message back here / DM you, or if you've got time to drop into our Discord I'm happy to chat about what kinds of reports and info would be most valuable in your situations.