jQuery 4.0.0 Release Candidate 1  ## Metadata - Author: [[Timmy Willison]] - Full Title: jQuery 4.0.0 Release Candidate 1 - Category: #articles - Document Note: --- tags: [#jQuery, #ReleaseCandidate, #FrontendDevelopment] - #jQuery4 - #ReleaseCandidate - #UpgradePath Author: Timmy Willison Source: Official jQuery Blog Reference: https://blog.jquery.com/2025/08/11/jquery-4-0-0-release-candidate-1/ date created: 2025-08-16 12:00 --- # Title: jQuery 4.0.0 Release Candidate 1 ## Table of Contents: - [📝 Summary](#-summary) - [📖 Main Content](#-main-content) - [🗒️ Notes](#️-notes) - [📖 References](#-references) - [🗣️ Paraphrase](#️-paraphrase) - [📰 Newsletter](#-newsletter) - [✅ Action Items](#-action-items) - [🧪 Hypotheses](#-hypotheses) - [📊 Methodology](#-methodology) - [❓ Questions](#-questions) - [🔮 Future Research](#-future-research) - [💡 Implications](#-implications) - [🧠 Learning Styles Assessment](#-learning-styles-assessment) - [📊 Accessibility Assessment](#-accessibility-assessment) - [🌍 DEIB Assessment](#-deib-assessment) - [✅ Logical validity](#-logical-validity) - [🔍 DARVO Analysis](#-darvo-analysis) - [🔍 SEO Evaluation](#-seo-evaluation) - [🎯 Conclusion](#-conclusion) --- ## ​ Summary: jQuery 4.0.0-rc.1 is now available as the first release candidate. It streamlines the codebase by removing legacy support (e.g., IE < 11), deprecated APIs, internal-only parameters, and complex "magic" behaviors. A slim build is offered, minus AJAX and Deferreds, and a migration guide alongside jQuery Migrate is ready to help transition. Download via CDN or npm is available now. :contentReference[oaicite:0]{index=0} --- ## ​ Main Content: The jQuery team invited users to rigorously test this candidate: "poke it with many sticks." In the release, outdated IE support and convoluted internal APIs are removed in favor of modern standards like DOMParser and native Promises. A smaller "slim" build excludes AJAX and Deferreds, leveraging modern browser features. Full downloads via CDN and npm are ready; public CDNs will follow. A corresponding upgrade guide and jQuery Migrate release will assist with migration. :contentReference[oaicite:1]{index=1} ### ​​ Notes - **Release Invitation** - “Poke it with many sticks”—heavy community testing encouraged. - If no major issues found, the final 4.0.0 release will follow. :contentReference[oaicite:2]{index=2} - **Codebase Cleanup** - Dropped support: IE < 11, deprecated APIs, undocumented internal parameters, overly complicated behaviors. :contentReference[oaicite:3]{index=3} - **New Slim Build** - Lighter version (~8 kB gzipped): no AJAX or Deferreds, allows use of native Promises. :contentReference[oaicite:4]{index=4} - **Availability** - Download via jQuery CDN or npm (e.g., `npm install [email protected]`). Third-party CDNs to follow later. :contentReference[oaicite:5]{index=5} - **Migration Support** - A 4.0 upgrade guide and jQuery Migrate release are available, but may evolve prior to final release. :contentReference[oaicite:6]{index=6} - **Community Acknowledgment** - Thanks extended to contributors and testers like ac-mmi, Michał Gołębiowski-Owczarek, neogy-akash, and the jQuery team. :contentReference[oaicite:7]{index=7} --- ## ​ References: - Willison, T. (2025, August 11). *jQuery 4.0.0 Release Candidate 1*. Official jQuery Blog. :contentReference[oaicite:8]{index=8} --- ## ​​ Paraphrase: 1. **Original**: *"It’s here! Almost. jQuery 4.0.0-rc.1 is now available. It’s our way of saying, 'we think this is ready; now poke it with many sticks'."* **Paraphrase**: The jQuery team announces jQuery 4.0 rc1 is live, and they'll rely on thorough user testing—"poke it with many sticks"—before months away from the final version. 2. **Original**: *"Many of the breaking changes in jQuery 4.0.0 are ones the team has wanted to make for years... removed support for IE before version 11... removed some previously-deprecated APIs... dropped support for some 'magic' behaviors that were overly complicated."* **Paraphrase**: The release finally brings long-awaited breaking changes: it eliminates legacy support for browsers like IE < 11, cleans out deprecated APIs and undocumented internal elements, and simplifies or removes unnecessarily complex features. --- ## ​ Newsletter: **✨ jQuery 4 RC1 Is Live!** Web devs, assemble: jQuery 4 Release Candidate 1 has arrived. This milestone marks the trimming of legacy code—thinking IE < 11, deprecated APIs, internal quirks—and introduces a sleek *slim* build focused on modern standards like native Promises. It's *your* time to test the waters (or "poke it with many sticks") before the final release. Grab it via CDN or npm, and don’t miss the upgrade guide and jQuery Migrate that’ll help you keep everything running smoothly. Stay sharp with jQuery! 🔗 [Read more on the jQuery Blog](https://blog.jquery.com/2025/08/11/jquery-4-0-0-release-candidate-1/) --- ## ​ Action Items: - Integrate key changes into **WordPress core upgrade guides**—highlight dropped IE support and dependencies. - Develop a **training module** demonstrating how to migrate legacy theme/plugin scripts to jQuery 4. - In OSPO discussions, reference this as a **model for phased deprecation and community involvement**. - Prepare **contributor-facing communications** explaining how these breaking changes uphold maintainability and modern standards. --- ## ​ Hypotheses: - H1: Projects that actively use jQuery Migrate will have fewer post-upgrade breakages. - H2: Removing legacy browser support reduces bundle size and improves site performance measurably. - H3: Developer adoption of the slim build increases when native Promises are robustly supported. ### ​ Methodology: - Perform case studies comparing plugin behavior with and without Migrate enabled. - Benchmark load times pre/post- slim build adoption in real-world applications. - Survey developers on perceived value of the slim build vs. full build usage. ### ​ Questions: - Which deprecated API removals will impact the largest number of WordPress themes/plugins? - What is the adoption rate for jQuery 4 RC1 among major plugin developers? - How can documentation be structured to reduce upgrade friction? ### ​ Future Research: - Longitudinal study on site performance and security before/after migrating to jQuery 4. - Analysis of deprecated API usage across the WordPress ecosystem. - Best practices for coordinating major JS library migrations in large-scale open-source platforms. ### ​ Implications: - Ensures WordPress stays leaner and more secure by leveraging modern browser features. - Encourages ecosystem-wide modernization and deprecation discipline. - Reinforces WP’s role as a forward-thinking, sustainable open-source project. --- ## ​ Learning Styles Assessment: - **Visual Learners**: Minimal visuals; could benefit from before-and-after code diff diagrams (improved). - **Aural Learners**: No audio; adding a short walkthrough podcast or narrated demo would help (improve). - **Verbal Learners**: Strong text explanations, clear examples (present). - **Physical Learners**: Step-by-step migration exercises would enhance hands-on learning (improve). - **Logical Learners**: Clear breakdown of changes and cause-effect (present). - **Social Learners**: Lacks links to discussion forums—adding links to GitHub or jQuery chat would help (improve). - **Solitary Learners**: Self-assessment checklist for upgrade readiness would be useful (improve). - **Naturalistic Learners**: Content is technical—nature analogies not applicable. --- ## ​ Accessibility Assessment: - The blog post is text-heavy with few images; ensure any visuals (e.g., code blocks) include alt-text or descriptive captions (improve). - Standard HTML assumptions; check for proper headers and code accessibility (present). - Ensure keyboard-friendly navigation for any interactive demos (improve). --- ## ​ DEIB Assessment: - Language is inclusive and neutral (present). - Could include examples from diverse developer contexts (small improvement). - Simplify technical phrasing or explain jargon to assist non-native speakers (improve). --- ## ​ Logical validity: - **Strengths**: - **Causal Reasoning**: Legacy removal → leaner, modern codebase. - **Sound Deductive Reasoning**: Removing old browser support - Summary: jQuery: The Write Less, Do More, JavaScript Library - URL: https://blog.jquery.com/2025/08/11/jquery-4-0-0-release-candidate-1/ It’s here! Almost. jQuery 4.0.0-rc.1 is now available. It’s our way of saying, “we think this is ready; now poke it with many sticks”. If nothing is found that requires a second release candidate, jQuery 4.0.0 final will follow. Please try out this release and [let us know if you encounter any issues](https://github.com/jquery/jquery/issues). A 4.0 upgrade guide and jQuery Migrate release are also now available, but both are subject to changes before the final jQuery Core release. Many of the breaking changes in jQuery 4.0.0 are ones the team has wanted to make for years, but couldn’t in a patch or minor release. We’ve trimmed legacy code (including removing support for IE before version 11), removed some previously-deprecated APIs, removed some internal-only parameters to public functions that were never documented, and dropped support for some “magic” behaviors that were overly complicated. As usual, the release is available on our CDN and the npm package manager. Third party CDNs will not be hosting this rc release, but will host the 4.0.0 final release later. Here are some highlights for jQuery 4.0.0 rc.1. You can get the files from the jQuery CDN, or link to them directly: <https://code.jquery.com/jquery-4.0.0-rc.1.js> <https://code.jquery.com/jquery-4.0.0-rc.1.min.js> You can also get this release from npm: `npm install [email protected]` Sometimes you don’t need ajax, or you prefer to use one of the many standalone libraries that focus on ajax requests. And often it is simpler to use a combination of CSS and class manipulation for web animations. Finally, all of jQuery’s supported browsers (except for IE11) now have support for native Promises across the board, so Deferreds and Callbacks are no longer needed in most cases. Along with the regular version of jQuery that includes everything, we’ve released a “slim” version that excludes these modules. The size of jQuery is very rarely a load performance concern these days, but the slim build is about 8k gzipped bytes smaller than the regular version. These files are also available in the npm package and on the CDN: <https://code.jquery.com/jquery-4.0.0-rc.1.slim.js> <https://code.jquery.com/jquery-4.0.0-rc.1.slim.min.js> These updates are already available as the current versions on npm. Information on all the ways to get jQuery is available at <https://jquery.com/download/>. Public CDNs receive their copies today, please give them a few days to post the files. If you’re anxious to get a quick start, use the files on our CDN until they have a chance to update. Thank you to all of you who participated in this release by submitting patches, reporting bugs, or testing, including [ac-mmi](https://github.com/ac-mmi), [Michał Gołębiowski-Owczarek](https://github.com/mgol), [neogy-akash](https://github.com/neogy-akash), and the whole jQuery team. **Full changelog:** [4.0.0-rc.1](https://github.com/jquery/jquery/compare/4.0.0-beta.2...4.0.0-rc.1), jQuery 4.0.0 Release Candidate 1, Timmy Willison, 01k2fr3w8bc0ea7b0g7ext55cr.