v4.0.0

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Changelog

https://blog.jquery.com/2026/01/17/jquery-4-0-0/

Ajax

• Don't treat array data as binary (992a1911)
• Allow processData: true even for binary data (ce264e07)
• Support binary data (including FormData) (a7ed9a7b)
• Support headers for script transport even when cross-domain (#​5142, 6d136443)
• Support null as success functions in jQuery.get (#​4989, 74978b7e)
• Don't auto-execute scripts unless dataType provided (#​4822, 025da4dd)
• Make responseJSON work for erroneous same-domain JSONP requests (68b4ec59)
• Execute JSONP error script responses (#​4771, a1e619b0)
• Avoid CSP errors in the script transport for async requests (#​3969, 07a8e4a1)
• Drop the json to jsonp auto-promotion logic (#​1799, #​3376, e7b3bc48)
• Overwrite s.contentType with content-type header value, if any (#​4119, 7fb90a6b)
• Deprecate AJAX event aliases, inline event/alias into deprecated (23d53928)
• Do not execute scripts for unsuccessful HTTP responses (#​4250, 50871a5a)
• Simplify jQuery.ajaxSettings.xhr (#​1967, abdc89ac)

Attributes

• Make .attr( name, false ) remove for all non-ARIA attrs (#​5388, 063831b6)
• Shave off a couple of bytes (b40a4807)
• Don't stringify attributes in the setter (#​4948, 4250b628)
• Drop the toggleClass(boolean|undefined) signature (#​3388, a4421101)
• Refactor val(): don't strip carriage return, isolate IE workarounds (ff281991)
• Don't set the type attr hook at all outside of IE (9e66fe9a)

CSS

• Fix dimensions of table <col> elements (#​5628, eca2a564)
• Drop the cache in finalPropName (640d5825)
• Tests: Fix tests & support tests under CSS Zoom (#​5489, 071f6dba)
• Fix reliableTrDimensions support test for initially hidden iframes (b1e66a5f)
• Selector: Align with 3.x, remove the outer selector.js wrapper (53cf7244)
• Make the reliableTrDimensions support test work with Bootstrap CSS (#​5270, 65b85031)
• Make offsetHeight( true ), etc. include negative margins (#​3982, bce13b72)
• Return undefined for whitespace-only CSS variable values (#​5120) (7eb00196)
• Don’t trim whitespace of undefined custom property (#​5105, ed306c02)
• Skip falsy values in addClass( array ), compress code (#​4998, a338b407)
• Justify use of rtrim on CSS property values (655c0ed5)
• Trim whitespace surrounding CSS Custom Properties values (#​4926, efadfe99)
• Include show, hide & toggle methods in the jQuery slim build (297d18dd)
• Remove the opacity CSS hook (865469f5)
• Workaround buggy getComputedStyle on table rows in IE/Edge (#​4490, 26415e08)
• Don't automatically add "px" to properties with a few exceptions (#​2795, 00a9c2e5)

Core

• Remove obsolete workarounds, update support comments (e2fe97b7)
• Switch $.parseHTML from document.implementation to DOMParser (0e123509)
• Fix the exports setup to make bundlers work with ESM & CommonJS (#​5416, 60f11b58)
• Add more info about named exports (5f869590)
• Simplify code post browser support reduction (93ca49e6)
• Move the factory to separate exports (46f6e3da)
• Use named exports in src/ (#​5262, f75daab0)
• Fix regression in jQuery.text() on HTMLDocument objects (#​5264, a75d6b52)
• Selector: Move jQuery.contains from the selector to the core module (024d8719)
• Drop the root parameter of jQuery.fn.init (d2436df3)
• Don't rely on splice being present on input (9c6f64c7)
• Manipulation: Add basic TrustedHTML support (#​4409, de5398a6)
• Report browser errors in parseXML (#​4784, 89697325)
• Make jQuery.isXMLDoc accept falsy input (#​4782, fd421097)
• Drop support for Edge Legacy (i.e. non-Chromium Microsoft Edge) (#​4568, e35fb62d)
• Fire iframe script in its context, add doc param in globalEval (#​4518, 4592595b)
• Exclude callbacks & deferred modules in the slim build as well (fbc44f52)
• Migrate from AMD to ES modules 🎉 (d0ce00cd)
• Use Array.prototype.flat where supported (#​4320, 9df4f1de)
• Remove private copies of push, sort & splice from the jQuery prototype (b59107f5)
• Implement .even() & .odd() to replace POS :even & :odd (78420d42)
• Deprecate jQuery.trim (#​4363, 5ea59460)
• Remove IE-specific support tests, rely on document.documentMode (#​4386, 3527a384)
• Drop support for IE <11, iOS <11, Firefox <65, Android Browser & PhantomJS (#​3950, #​4299, cf84696f)
• Remove deprecated jQuery APIs (#​4056, 58f0c00b)

Data

• Refactor to reduce size (805cdb43)
• Event:Manipulation: Prevent collisions with Object.prototype (#​3256, 9d76c0b1)
• Separate data & css/effects camelCase implementations (#​3355, 8fae2120)

Deferred

• Rename getStackHook to getErrorHook (#​5201, 258ca1ec)
• Respect source maps in jQuery.Deferred.exceptionHook (#​3179, 0b9c5037)
• Rename master to primary (a32cf632)

Deprecated

• Define .hover() using non-deprecated methods (fd6ffc5e)
• Remove jQuery.trim (0b676ae1)
• Fix AMD parameter order (f810080e)

Dimensions

• Add offset prop fallback to FF for unreliable TR dimensions (#​4529, 3bbbc111)

Docs

• Fix some minor issues in comments (e4d4dd81)
• update herodevs link in README (#​5695, 093e63f9)
• Align CONTRIBUTING.md with 3.x-stable (d9281061)
• Update CONTRIBUTING.md (4ef25b0d)
• add version support section to README (cbc2bc1f)
• Update remaining HTTP URLs to HTTPS (7cdd8374)
• Fix module links in the package README (ace646f6)
• update watch task in CONTRIBUTING.md (77d6ad71)
• Fix typos found by codespell (620870a1)
• remove stale gitter badge from readme (67cb1af7)
• Remove the "Grunt build" section from the PR template (988a5684)
• Remove stale badge from README (bcd9c2bc)
• Update the README of the published package (edccabf1)
• Remove git.io from a GitHub Actions comment (016872ff)
• Update webpack website in README (01819bc3)
• add link to patchwelcome and help wanted issues (924b7ce8)
• add link to preview the new CLAs (683ceb8f)
• Fix incorrect trac-NUMBER references (eb9ceb2f)
• remove expired links from old jquery source (#​4997) (ed066ac7)
• Remove links to Web Archive from source (#​4981, e24f2dcf)
• Replace #NUMBER Trac issue references with trac-NUMBER (5d5ea015)
• Update the URL to the latest jQuery build in CONTRIBUTING.md (9bdb16cd)
• Remove the CLA checkbox in the pull request template (e1248931)
• update irc to Libera and fix LAMP dead link (175db73e)
• Update Frequently Reported Issues in the GitHub issue template (7a6fae6a)
• Change JS Foundation mentions to OpenJS Foundation (11611967)
• add SECURITY.md, show security email address (2ffe54ca)
• Fix typos (1a7332ce)
• Update the link to the jsdom repository (a62309e0)
• Use https for hyperlinks in README (73415da2)
• Remove a mention of the event/alias.js module from README (3edfa1bc)
• Update links to EdgeHTML issues to go through Web Archive (1dad1185)
• direct users to GitHub docs for cloning the repo (f1c16de2)
• Change OS X to macOS in README (5a3e0664)
• Update most URLs to HTTPS (f09d9210)
• Convert link to Homebrew from HTTP to HTTPS (e0022f23)

Effect

• Fix a unnecessary conditional statement in .stop() (#​4374, 110802c7)

Effects

• Remove jQuery.fx.interval (6c2c7362)

Event

• Use .preventDefault() in beforeunload (7c123dec)
• Increase robustness of an inner native event in leverageNative (#​5459, 527fb3dc)
• Avoid collisions between jQuery.event.special & Object.prototype (bcaeb000)
• Simplify the check for saved data in leverageNative (dfe212d5)
• Make trigger(focus/blur/click) work with native handlers (#​5015, 6ad3651d)
• Simulate focus/blur in IE via focusin/focusout (#​4856, #​4859, #​4950, ce60d318)
• Don't break focus triggering after .on(focus).off(focus) (#​4867, e539bac7)
• Make focus re-triggering not focus the original element back (#​4382, dbcffb39)
• Don't crash if an element is removed on blur (#​4417, 5c2d0870)
• Remove the event.which shim (#​3235, 1a5fff4c)
• remove jQuery.event.global (18db8717)
• Only attach events to objects that accept data - for real (#​4397, d5c505e3)
• Stop shimming focusin & focusout events (#​4300, 8a741376)
• Prevent leverageNative from registering duplicate dummy handlers (eb6c0a7c)
• Fix handling of multiple async focus events (#​4350, ddfa8376)

Manipulation

• Make jQuery.cleanData not skip elements during cleanup (#​5214, 3cad5c43)
• Generalize a test to support IE (88690ebf)
• Support $el.html(selfRemovingScript) (#​5378) (#​5377, 937923d9)
• Extract domManip to a separate file (ee6e8740)
• Don't remove HTML comments from scripts (#​4904, 2f8f39e4)
• Respect script crossorigin attribute in DOM manipulation (#​4542, 15ae3614)
• Avoid concatenating strings in buildFragment (9c98e4e8)
• Make jQuery.htmlPrefilter an identity function (90fed4b4)
• Selector: Use the nodeName util where possible to save size (4504fc3d)

Offset

• Increase search depth when finding the 'real' offset parent (556eaf4a)

Release

• 4.0.0 (4f2fae08)
• remove dist files from main branch (c838cfb5)
• 4.0.0-rc.2 (97525193)
• Update AUTHORS.txt (c128d5d8)
• Fix release issues uncovered during the 4.0.0-rc.1 release (a5b0c431)
• remove dist files from main branch (9d06c6dd)
• 4.0.0-rc.1 (586182f3)
• 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)
• 4.0.0-beta.2 (51fffe9f)
• ensure builds have the proper version (3e612aee)
• set preReleaseBase in config file (1fa8df5d)
• fix running pre/post release scripts in windows (5518b2da)
• update AUTHORS.txt (862e7a18)
• migrate release process to release-it (jquery/jquery-release#114, 2646a8b0)
• add factory files to release distribution (#​5411, 1a324b07)
• use buildDefaultFiles directly and pass version (b507c864)
• copy dist-module folder as well (63767650)
• only published versioned files to cdn (3a0ca684)
• remove scripts and dev deps from dist package.json (7eac932d)
• update build command in Release.generateArtifacts (3b963a21)
• add support for md5 sums in windows (f088c366)
• remove the need to install grunt globally (b2bbaa36)
• upgrade release dependencies (967af732)
• Remove an unused chalk dependency (bfb6897c)
• Use an in-repository dist README fixture (358b769a)
• Update AUTHORS.txt (1b74660f)
• update AUTHORS.txt (cf9fe0f6)

Selector

• Remove the workaround for :has; test both on iPhone & iPad (65e35450)
• Properly deprecate jQuery.expr[ ":" ]/jQuery.expr.filters (329661fd)
• Make selector.js module depend on attributes/attr.js (#​5379, e06ff088)
• Eliminate selector.js depenencies from various modules (e8b7db4b)
• Re-expose jQuery.find.{tokenize,select,compile,setDocument} (#​5259, 338de359)
• Stop relying on CSS.supports( "selector(...)" ) (#​5194, 68aa2ef7)
• Backport jQuery selection context logic to selector-native (#​5185, 2e644e84)
• Make selector lists work with qSA again (#​5177, 09d988b7)
• Implement the uniqueSort chainable method (#​5166, 5266f23c)
• Re-introduce selector-native.js (4c1171f2)
• Manipulation: Fix DOM manip within template contents (#​5147, 3299236c)
• Drop support for legacy pseudos, test custom pseudos (8c7da22c)
• Use jQuery :has if CSS.supports(selector(...)) non-compliant (#​5098, d153c375)
• Remove the "a:enabled" workaround for Chrome <=77 (c1ee33ad)
• Make empty attribute selectors work in IE again (#​4435, 05184cc4)
• Use shallow document comparisons in uniqueSort (#​4441, 15750b0a)
• Add a test for throwing on post-comma invalid selectors (6eee5f7f)
• Make selectors with leading combinators use qSA again (ed66d5a2)
• Use shallow document comparisons to avoid IE/Edge crashes (#​4441, aa6344ba)
• reduce size, simplify setDocument (29a9544a)
• Leverage the :scope pseudo-class where possible (#​4453, df6a7f7f)
• Bring back querySelectorAll shortcut usage (cef4b731)
• Inline Sizzle into the selector module (47835965)
• Port Sizzle tests to jQuery (79b74e04)

Support

• ensure display is set to block for the support div (#​4832, 09f25436)

Tests

• Fix the "outside view position" test in Headless Chrome (23d72cb1)
• Fix selector tests in Chrome 141 (25a1b080)
• Increase nomodule test timeout for IE from 1s to 5s (5eab0a3c)
• Fix module/nomodule tests flakiness (5964acf3)
• 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)
• remove unnecessary scroll feature test (ea31e4d5)
• Align :has selector tests with 3.x-stable (f2d9fde5)
• revert concurrency group change (fa73e2f1)
• include github ref in concurrency group (5880e027)
• Make the beforeunload event tests work regardless of extensions (399a78ee)
• share queue/browser handling for all worker types (284b082e)
• improve diffing for values of different types (b9d333ac)
• show any and all actual/expected values (f80e78ef)
• add diffing to test reporter (44fb7fa2)
• add actual and expected messages to test reporter (1e84908b)
• fix worker restarts for failed browser acknowledgements (fedffe74)
• add --hard-retries option to test runner (822362e6)
• fix cleanup in cases where server doesn't stop (0754d596)
• fix flakey message logs; ignore delete worker failures (02d23478)
• reuse browser workers in BrowserStack tests (#​5428) (95a4c94b)
• Use allowlist instead of whitelist (2b97b6bb)
• migrate testing infrastructure to minimal dependencies (dfc693ea)
• Fix Karma tests on Node.js 20 (d478a1c0)
• Disable the ":lang respects escaped backslashes" test (#​5271, 62b9a258)
• Indicate Chrome 112 & Safari 16.4 pass the cssHas support test (89ef81f8)
• Test AJAX deprecated event aliases properly (cff28998)
• Indicate Firefox 106+ passes the cssSupportsSelector test (716130e0)
• Remove a workaround for a Firefox XML parsing issue (e7ffe1f1)
• Fix the link to QUnit CSS file (8cf39b78)
• Exclude tests based on compilation flags, not API presence (#​5069, fae5fee8)
• Workaround an XML parsing bug in Firefox (af1cd6f2)
• lock colors version to 1.4.0 (9603b3c8)
• Skip ETag AJAX tests on TestSwarm (00c060d1)
• Allow statusText to be "success" in AJAX tests (19ced963)
• Make Karma browser timeout larger than the QUnit one (4fd6912b)
• Don't remove csp.log in the cspClean action of mock.php (1019074f)
• Load the TestSwarm listener via HTTPS (d225639a)
• Switch background image from online file to local 1x1.jpg (482f8462)
• Strip untypical callback parameter characters from mock.php (a7027463)
• Make more tests run natively in Chrome & Firefox (50e8e846)
• Fix tests for not auto-executing scripts without dataType (d38528b1)
• Recognize callbacks with dots in the Node.js mock server (df6858df)
• Skip the "jQuery.ajax() on unload" test in Safari (c18dc496)
• Remove an unused local variable (82b87f6f)
• Remove remaining obsolete jQuery.cache references (d96111e1)
• Workaround failures in recent XSS tests in iOS 8 - 12 (11066a9e)
• Add tests for recently fixed manipulation XSS issues (dc06d68b)
• Use only one focusin/out handler per matching window & document (9b732043)
• Fix flakiness in the "jQuery.ajax() - JSONP - Same Domain" test (7b0864d0)
• Pass a number of necessary done() calls to assert.async() (364476c3)
• Remove obsolete jQuery data tests (eb35be52)
• Skip a "width/height on a table row with phantom borders" test in Firefox (a612733b)
• Don't test synchronous XHR on unload in Chrome (323575fb)
• Stop using jQuery.find in tests (1d624c10)
• Port changes from Sizzle (ac5f7cd8)
• Fix a comment in testinit.js (7bdf307b)
• update npo.js and include unminified source instead (b334ce77)
• Restrict an event test fallback to TestSwarm (bde53edc)
• Fix the new focusin/focusout test in IE (6f2fae7c)
• Fix the core-js polyfill inclusion method (2e4b79ab)

Traversing

• Fix contents() on <object>s with children in IE (ccbd6b93)
• Fix contents() on <object>s with children (#​4384, 4d865d96)

Upgrade

• Bump actions/setup-node from 3.3.0 to 3.4.1 (78321f07)
• set up periodic code scanning analysis (39c5778c)
• updated the vulnerability reporting process and added escalation steps (02cf4ee0)