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<div> <h1 align="center"><a href="https://epicreact.dev/performance">โšก React Performance ๐Ÿš€ EpicReact.Dev</a></h1> <strong> React is fast, until it isn't </strong> <p> Learn everything you need to diagnose, profile, and fix performance problems in your React application using the Browser Performance Profiler, React DevTools Profiler, and proven React optimization techniques. </p> <a href="https://epicreact.dev"> <img alt="Learn React from Start to Finish" src="https://kentcdodds.com/images/epicreact-promo/er-1.gif" /> </a> </div> <hr /> <!-- prettier-ignore-start -->

Build Status All Contributors GPL 3.0 License Code of Conduct Gitpod ready-to-code

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Prerequisites

NOTE: The EpicReact.dev videos were recorded with React version ^16.13 and all material in this repo has been updated to React version ^18. Differences are minor and any relevant differences are noted in the instructions.

Quick start

It's recommended you run everything in the same environment you work in every day, but if you don't want to set up the repository locally, you can get started in one click with Gitpod, CodeSandbox, or by following the video demo instructions for GitHub Codespaces.

Open in Gitpod

For a local development environment, follow the instructions below

System Requirements

All of these must be available in your PATH. To verify things are set up properly, you can run this:

git --version
node --version
npm --version

If you have trouble with any of these, learn more about the PATH environment variable and how to fix it here for windows or mac/linux.

Setup

If you want to commit and push your work as you go, you'll want to fork first and then clone your fork rather than this repo directly.

After you've made sure to have the correct things (and versions) installed, you should be able to just run a few commands to get set up:

git clone https://github.com/kentcdodds/react-performance.git
cd react-performance
node setup

This may take a few minutes. It will ask you for your email. This is optional and just automatically adds your email to the links in the project to make filling out some forms easier.

If you get any errors, please read through them and see if you can find out what the problem is. If you can't work it out on your own then please file an issue and provide all the output from the commands you ran (even if it's a lot).

If you can't get the setup script to work, then just make sure you have the right versions of the requirements listed above, and run the following commands:

npm install
npm run validate

If you are still unable to fix issues and you know how to use Docker ๐Ÿณ you can setup the project with the following command:

docker-compose up

Running the app

To get the app up and running (and really see if it worked), run:

npm start

This should start up your browser. If you're familiar, this is a standard react-scripts application.

You can also open the deployment of the app on Netlify.

Running the tests

npm test

This will start Jest in watch mode. Read the output and play around with it. The tests are there to help you reach the final version, however sometimes you can accomplish the task and the tests still fail if you implement things differently than I do in my solution, so don't look to them as a complete authority.

Exercises

The purpose of the exercise is not for you to work through all the material. It's intended to get your brain thinking about the right questions to ask me as I walk through the material.

Helpful Emoji ๐Ÿจ ๐Ÿ’ฐ ๐Ÿ’ฏ ๐Ÿ“ ๐Ÿฆ‰ ๐Ÿ“œ ๐Ÿ’ฃ ๐Ÿ’ช ๐Ÿ ๐Ÿ‘จโ€๐Ÿ’ผ ๐Ÿšจ

Each exercise has comments in it to help you get through the exercise. These fun emoji characters are here to help you.

Contributors

Thanks goes to these wonderful people (emoji key):

<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section --> <!-- prettier-ignore-start --> <!-- markdownlint-disable --> <table> <tbody> <tr> <td align="center" valign="top" width="14.28%"><a href="https://kentcdodds.com"><img src="https://avatars.githubusercontent.com/u/1500684?v=3?s=100" width="100px;" alt="Kent C. Dodds"/><br /><sub><b>Kent C. Dodds</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=kentcdodds" title="Code">๐Ÿ’ป</a> <a href="https://github.com/kentcdodds/react-performance/commits?author=kentcdodds" title="Documentation">๐Ÿ“–</a> <a href="#infra-kentcdodds" title="Infrastructure (Hosting, Build-Tools, etc)">๐Ÿš‡</a> <a href="https://github.com/kentcdodds/react-performance/commits?author=kentcdodds" title="Tests">โš ๏ธ</a></td> <td align="center" valign="top" width="14.28%"><a href="https://stackshare.io/jdorfman/decisions"><img src="https://avatars1.githubusercontent.com/u/398230?v=4?s=100" width="100px;" alt="Justin Dorfman"/><br /><sub><b>Justin Dorfman</b></sub></a><br /><a href="#fundingFinding-jdorfman" title="Funding Finding">๐Ÿ”</a></td> <td align="center" valign="top" width="14.28%"><a href="https://bol.vin"><img src="https://avatars2.githubusercontent.com/u/1684826?v=4?s=100" width="100px;" alt="Frรฉdรฉric Bolvin"/><br /><sub><b>Frรฉdรฉric Bolvin</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Fensterbank" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://vojta.io"><img src="https://avatars2.githubusercontent.com/u/25487857?v=4?s=100" width="100px;" alt="Vojta Holik"/><br /><sub><b>Vojta Holik</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=vojtaholik" title="Code">๐Ÿ’ป</a> <a href="#design-vojtaholik" title="Design">๐ŸŽจ</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/marcosvega91"><img src="https://avatars2.githubusercontent.com/u/5365582?v=4?s=100" width="100px;" alt="Marco Moretti"/><br /><sub><b>Marco Moretti</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=marcosvega91" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://ricardobusquet.com"><img src="https://avatars1.githubusercontent.com/u/7198302?v=4?s=100" width="100px;" alt="Ricardo Busquet"/><br /><sub><b>Ricardo Busquet</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=rbusquet" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/nywleswoey"><img src="https://avatars3.githubusercontent.com/u/28249994?v=4?s=100" width="100px;" alt="Selwyn Yeow"/><br /><sub><b>Selwyn Yeow</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=nywleswoey" title="Code">๐Ÿ’ป</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="https://github.com/emzoumpo"><img src="https://avatars2.githubusercontent.com/u/2103443?v=4?s=100" width="100px;" alt="Emmanouil Zoumpoulakis"/><br /><sub><b>Emmanouil Zoumpoulakis</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=emzoumpo" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://peter.hozak.info/"><img src="https://avatars0.githubusercontent.com/u/1087670?v=4?s=100" width="100px;" alt="Peter Hozรกk"/><br /><sub><b>Peter Hozรกk</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Aprillion" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://www.linkedin.com/in/pritamsangani/"><img src="https://avatars3.githubusercontent.com/u/22857896?v=4?s=100" width="100px;" alt="Pritam Sangani"/><br /><sub><b>Pritam Sangani</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=PritamSangani" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/milamer"><img src="https://avatars2.githubusercontent.com/u/12884134?v=4?s=100" width="100px;" alt="Christian Schurr"/><br /><sub><b>Christian Schurr</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=milamer" title="Code">๐Ÿ’ป</a> <a href="https://github.com/kentcdodds/react-performance/commits?author=milamer" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://magrippis.com"><img src="https://avatars0.githubusercontent.com/u/3502800?v=4?s=100" width="100px;" alt="Johnny Magrippis"/><br /><sub><b>Johnny Magrippis</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=jmagrippis" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/AhmedAymanM"><img src="https://avatars1.githubusercontent.com/u/535126?v=4?s=100" width="100px;" alt="Ahmed"/><br /><sub><b>Ahmed</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=AhmedAymanM" title="Code">๐Ÿ’ป</a> <a href="https://github.com/kentcdodds/react-performance/commits?author=AhmedAymanM" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/RobbertWolfs"><img src="https://avatars2.githubusercontent.com/u/12511178?v=4?s=100" width="100px;" alt="Robbert Wolfs"/><br /><sub><b>Robbert Wolfs</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=RobbertWolfs" title="Documentation">๐Ÿ“–</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="https://www.gwanduke.com"><img src="https://avatars0.githubusercontent.com/u/7443435?v=4?s=100" width="100px;" alt="Kim Gwan-duk"/><br /><sub><b>Kim Gwan-duk</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=gwanduke" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://rasmusjosefsson.com"><img src="https://avatars2.githubusercontent.com/u/13612444?v=4?s=100" width="100px;" alt="Rasmus Josefsson"/><br /><sub><b>Rasmus Josefsson</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=rajjejosefsson" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/MarcosNASA"><img src="https://avatars3.githubusercontent.com/u/45607262?v=4?s=100" width="100px;" alt="Marcos NASA G"/><br /><sub><b>Marcos NASA G</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=MarcosNASA" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/Snaptags"><img src="https://avatars1.githubusercontent.com/u/1249745?v=4?s=100" width="100px;" alt="Markus Lasermann"/><br /><sub><b>Markus Lasermann</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Snaptags" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://vk.com/vasilii_kovalev"><img src="https://avatars0.githubusercontent.com/u/10310491?v=4?s=100" width="100px;" alt="Vasilii Kovalev"/><br /><sub><b>Vasilii Kovalev</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=vasilii-kovalev" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/matchai"><img src="https://avatars0.githubusercontent.com/u/4658208?v=4?s=100" width="100px;" alt="Matan Kushner"/><br /><sub><b>Matan Kushner</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=matchai" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://michaeldeboey.be"><img src="https://avatars3.githubusercontent.com/u/6643991?v=4?s=100" width="100px;" alt="Michaรซl De Boey"/><br /><sub><b>Michaรซl De Boey</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=MichaelDeBoey" title="Code">๐Ÿ’ป</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="http://www.veljkoblagojevic.com"><img src="https://avatars2.githubusercontent.com/u/28904821?v=4?s=100" width="100px;" alt="Veljko Blagojevic"/><br /><sub><b>Veljko Blagojevic</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Wekios" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://bobbywarner.com"><img src="https://avatars0.githubusercontent.com/u/554961?v=4?s=100" width="100px;" alt="Bobby Warner"/><br /><sub><b>Bobby Warner</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=bobbywarner" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="http://angular-tips.com"><img src="https://avatars2.githubusercontent.com/u/1087957?v=4?s=100" width="100px;" alt="Jesรบs Rodrรญguez"/><br /><sub><b>Jesรบs Rodrรญguez</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Foxandxss" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://valentin-hervieu.fr"><img src="https://avatars2.githubusercontent.com/u/2678610?v=4?s=100" width="100px;" alt="Valentin Hervieu"/><br /><sub><b>Valentin Hervieu</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/issues?q=author%3AValentinH" title="Bug reports">๐Ÿ›</a></td> <td align="center" valign="top" width="14.28%"><a href="https://davsanchez.com"><img src="https://avatars2.githubusercontent.com/u/2999604?v=4?s=100" width="100px;" alt="David Sรกnchez"/><br /><sub><b>David Sรกnchez</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=d4vsanchez" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://merott.com"><img src="https://avatars3.githubusercontent.com/u/1757708?v=4?s=100" width="100px;" alt="Merott Movahedi"/><br /><sub><b>Merott Movahedi</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Merott" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://www.arjenbloemsma.nl"><img src="https://avatars1.githubusercontent.com/u/8061052?v=4?s=100" width="100px;" alt="Arjen Bloemsma"/><br /><sub><b>Arjen Bloemsma</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=arjenbloemsma" title="Documentation">๐Ÿ“–</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="https://www.linkedin.com/in/syed-naveed-elahi/"><img src="https://avatars.githubusercontent.com/u/19769879?v=4?s=100" width="100px;" alt="Naveed Elahi"/><br /><sub><b>Naveed Elahi</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=BboyStatix" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://tknappe.com/"><img src="https://avatars.githubusercontent.com/u/138048?v=4?s=100" width="100px;" alt="Tyler Knappe"/><br /><sub><b>Tyler Knappe</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=knappe" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/0xnoob"><img src="https://avatars.githubusercontent.com/u/49793844?v=4?s=100" width="100px;" alt="0xnoob"/><br /><sub><b>0xnoob</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=0xnoob" title="Code">๐Ÿ’ป</a> <a href="https://github.com/kentcdodds/react-performance/commits?author=0xnoob" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://emildev.netlify.app/"><img src="https://avatars.githubusercontent.com/u/10499067?v=4?s=100" width="100px;" alt="Emil Esplund"/><br /><sub><b>Emil Esplund</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=esplito" title="Tests">โš ๏ธ</a></td> <td align="center" valign="top" width="14.28%"><a href="http://swiftwithjustin.co"><img src="https://avatars.githubusercontent.com/u/5117473?v=4?s=100" width="100px;" alt="Justin Stanley"/><br /><sub><b>Justin Stanley</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=jstheoriginal" title="Tests">โš ๏ธ</a></td> <td align="center" valign="top" width="14.28%"><a href="http://pavlos.dev"><img src="https://avatars.githubusercontent.com/u/100233?v=4?s=100" width="100px;" alt="Pavlos Vinieratos"/><br /><sub><b>Pavlos Vinieratos</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=pvinis" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/Reignable"><img src="https://avatars.githubusercontent.com/u/18505669?v=4?s=100" width="100px;" alt="Joe Barrett"/><br /><sub><b>Joe Barrett</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=Reignable" title="Code">๐Ÿ’ป</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="https://github.com/LochMess"><img src="https://avatars.githubusercontent.com/u/18762221?v=4?s=100" width="100px;" alt="LochMess"/><br /><sub><b>LochMess</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=LochMess" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://codewars.com/users/mstosio"><img src="https://avatars.githubusercontent.com/u/10117225?v=4?s=100" width="100px;" alt="Michal"/><br /><sub><b>Michal</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=mstosio" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/marioleed"><img src="https://avatars.githubusercontent.com/u/1763448?v=4?s=100" width="100px;" alt="Mario Sannum"/><br /><sub><b>Mario Sannum</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=marioleed" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/CJThornburg"><img src="https://avatars.githubusercontent.com/u/59716885?v=4?s=100" width="100px;" alt="CJThornburg"/><br /><sub><b>CJThornburg</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=CJThornburg" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="http://www.lucianoayres.com.br"><img src="https://avatars.githubusercontent.com/u/20209393?v=4?s=100" width="100px;" alt="Luciano Ayres"/><br /><sub><b>Luciano Ayres</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=lucianoayres" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/skgyan"><img src="https://avatars.githubusercontent.com/u/5046860?v=4?s=100" width="100px;" alt="Sushil Kumar"/><br /><sub><b>Sushil Kumar</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=skgyan" title="Code">๐Ÿ’ป</a></td> <td align="center" valign="top" width="14.28%"><a href="http://unravelweb.dev"><img src="https://avatars.githubusercontent.com/u/26349046?v=4?s=100" width="100px;" alt="Nishu Goel"/><br /><sub><b>Nishu Goel</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=NishuGoel" title="Documentation">๐Ÿ“–</a></td> </tr> <tr> <td align="center" valign="top" width="14.28%"><a href="https://creador.dev"><img src="https://avatars.githubusercontent.com/u/40248406?v=4?s=100" width="100px;" alt="Pawan Kumar"/><br /><sub><b>Pawan Kumar</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=creador-dev" title="Documentation">๐Ÿ“–</a></td> <td align="center" valign="top" width="14.28%"><a href="https://github.com/xhocopuff"><img src="https://avatars.githubusercontent.com/u/62633485?v=4?s=100" width="100px;" alt="Melesia Thompson"/><br /><sub><b>Melesia Thompson</b></sub></a><br /><a href="https://github.com/kentcdodds/react-performance/commits?author=xhocopuff" title="Documentation">๐Ÿ“–</a></td> </tr> </tbody> </table> <!-- markdownlint-restore --> <!-- prettier-ignore-end --> <!-- ALL-CONTRIBUTORS-LIST:END -->

This project follows the all-contributors specification. Contributions of any kind welcome!

Workshop Feedback

Each exercise has an Elaboration and Feedback link. Please fill that out after the exercise and instruction.

At the end of the workshop, please go to this URL to give overall feedback. Thank you! https://kcd.im/rp-ws-feedback

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