Changelog

https://blog.jquery.com/2025/08/11/jquery-4-0-0-release-candidate-1/

Build

• Make the sed usage portable across Linux & macOS (a848611f)
• Bump form-data from 4.0.2 to 4.0.4 (70ee64fc)
• Test on Safari 18 & 17 instead of "latest-1" (958369f0)
• Bump github/codeql-action in the github-actions group (19621e99)
• Update the jQuery license link in comment headers (ec9a387e)
• Try to unpack Firefox ESR via xz, fall back to bzip2 (dc5d1f7c)
• Bump github/codeql-action in the github-actions group (0ef60202)
• Bump undici and release-it (b668be0f)
• Bump the github-actions group with 2 updates (bd6b453b)
• Bump the github-actions group with 3 updates (de2ecfc0)
• ESLint: Remove the outerIIFEBody exception to indent (50ca9571)
• Bump the github-actions group with 2 updates (447432f4)
• upgrade dependencies, including jtr@0.2.5 (047f8683)
• Bump the github-actions group with 2 updates (667321eb)
• Bump the github-actions group across 1 directory with 2 updates (098591e6)
• Test on iOS 18, no longer test on iOS 15 (75b48e6a)
• Bump github/codeql-action from 3.27.0 to 3.27.5 in the github-actions group (03e183c4)
• Report Brotli sizes in compareSize (e4b5e622)
• Fix pre release matching in compare size regex (041f6e34)
• Make middleware-mockserver not crash on reading nonexistent files (d5ebb464)
• Bump the github-actions group with 4 updates (07c9f02b)
• Run tests on Node 22 & 23 (19716254)
• Enforce ECMAScript 5 in tests via ESLint (#5542, d74fc265)
• Bump the github-actions group with 3 updates (3ebe89f6)
• Bump rollup from 4.19.0 to 4.22.4 (147964e1)
• Bump webpack from 5.93.0 to 5.94.0 (3658caf1)
• Bump github/codeql-action from 3.25.15 to 3.26.6 in the github-actions group (a6feeaa7)
• align eslint config with 3.x branch as much as possible (7e6cee72)
• Bump the github-actions group with 2 updates (55bc35bc)
• upgrade dependencies, including requirejs to 2.3.7 (a7d3383e)
• use --input-type=module in npm scripts (57ef12e0)

CSS

• Fix dimensions of table <col> elements (#5628, eca2a564)
• Drop the cache in finalPropName (640d5825)

Core

• Remove obsolete workarounds, update support comments (e2fe97b7)
• Switch $.parseHTML from document.implementation to DOMParser (0e123509)

Docs

• Align CONTRIBUTING.md with 3.x-stable (d9281061)
• Update CONTRIBUTING.md (4ef25b0d)
• add version support section to README (cbc2bc1f)

Event

• Use .preventDefault() in beforeunload (7c123dec)

Manipulation

• Make jQuery.cleanData not skip elements during cleanup (#5214, 3cad5c43)

Release

• Run npm publish in the post-release phase (ff1f0eaa)
• Only run browserless tests during the release (fb5ab0f5)
• Temporarily disable running tests on release (3f79644b)
• publish tmp/release/dist folder when releasing (#5658, a865212d)
• correct build date in verification; other improvements (53ad94f3)
• remove dist files from main branch (be048a02)

Selector

• Properly deprecate jQuery.expr[ ":" ]/jQuery.expr.filters (329661fd)

Tests

• Use releases.jquery.com as external host for AJAX testing (f21a6ea6)
• Fix tests for jQuery.get( String, null-ish, null-ish, String ) (05325801)
• Add tests for jQuery.get( String, null-ish, null-ish, String ) (76687566)
• Backport the hidden="until-found" attr tests from 3.x-stable (3a31866b)
• migrate test runner to jquery-test-runner (733e62d2)
• Add custom attribute getter tests to the selector module (44667709)
• Switch to an updated fork of promises-aplus-tests (559bc5ac)
• Run tests in Edge in IE mode in GitHub Actions (6d78c076)
• Run tests on both real Firefox ESRs (4b7ecbad)
• align mock.php spacing with 3.x-stable branch (d5ae14f6)
• replace dead links in qunit fixture (dbc9dac7)
• replace express with basic Node server (c85454a8)