Released on Wednesday, September 30 2026

What's Changed

• Improved cancellation of queued timer callbacks (#1357) @PrzemyslawKlys
• Improved configuration / setup performance (#1360) @PrzemyslawKlys
• Fixed form submission ignoring sandbox restrictions (#1358) @PrzemyslawKlys
• Fixed <base> elements not following frozen document base URL and tree-order mutation rules (#1355, #1362)
• Fixed native Unloading handlers subscribing to unloading instead of beforeunload (#1354) @PrzemyslawKlys
• Added OnReset event to inform script hosts of native listener removals (#1356) @PrzemyslawKlys
• Added pull-based HTML serialization stream (#1361) @PrzemyslawKlys
• Released 1.8.3 by @FlorianRappl in #1363

New Contributors

• @PrzemyslawKlys made their first contribution in #1356

Full Changelog: v1.8.2...v1.8.3

Released on Friday, September 18 2026

What's Changed

• Improved attribute selector serialization to write only the case-sensitivity modifier that was specified (#1351)
• Improved id/name lookup on collections (document.forms["x"], form.elements["x"], ...) to enumerate the underlying sequence once instead of twice
• Improved performance of form.elements / fieldset.elements by walking the tree directly (#1350)
• Improved GetElementsByTagName / GetElementsByClassName traversal to stop double-scanning each element's children
• Improved selector specificity (Selectors.Specificity, ComplexSelector.Specificity) to be computed once instead of recomputed on every read
• Improved ListSelector.GetMatchingSelector to sort its selectors once instead of on every call
• Improved performance of HTML tree construction by keeping mutation logic out of it (#1347)
• Improved performance of DOM mutations by building a mutation record only when an observer will consume it (#1347)
• Improved performance of parser attribute duplication check
• Fixed Document.Forms allocating a new collection instance per read, contradicting its own [DomSameObject] contract
• Fixed classList and the other reflected token lists writing their content attribute without running the attribute change steps or queueing a mutation record
• Fixed clearing a reflected boolean attribute such as disabled removing it without running the attribute change steps or queueing a mutation record
• Fixed vulnerability via SVG style serialization (GHSA-cgp3-27rh-pcp2)
• Fixed a StackOverflowException when parsing a document with deeply nested unclosed <template> elements
• Added Document.MutationVersion, a synchronous counter of DOM mutations that a parse leaves unchanged (#1344, #1347)
• Released 1.8.2 by @FlorianRappl in #1353

New Contributors

• @RichardJansma made their first contribution in #1352

Full Changelog: v1.8.1...v1.8.2

Released on Thursday, September 10 2026

What's Changed

• Updated DoFocus and DoBlur to apply to form elements
• Improved explicit form ownership to take precedence over ancestor forms for connected controls (#1323) @sebastienros
• Fixed HTML hyperlink pseudo-classes omitting empty href and matching link elements (#1337) @sebastienros
• Fixed HTML-namespace element creation losing local-name case (#1327) @sebastienros
• Fixed :enabled incorrectly matching HTML links with nonempty href (#1324) @sebastienros
• Fixed changing focus of elements
• Released 1.8.1 by @FlorianRappl in #1343

New Contributors

• @sebastienros made their first contribution in #1338

Full Changelog: v1.8.0...v1.8.1

Released on Saturday, September 5 2026

What's Changed

• Improved AngleSharp's test website
• Fixed script data escaped state potentially not bouncing back correctly
• Added the DomSameObject annotation for the respective IDL members (#1314) @lahma
• Added the DomReturnType annotation for methods returning a different IDL type (#1318)
• Released 1.8.0 by @FlorianRappl in #1317

Full Changelog: v1.7.3...v1.8.0

Released on Thursday, September 3 2026

What's Changed

• Improved tracking of parse exceptions in the HtmlParser (#1315) @lahma
• Fixed tokenizer buffer overrun on encoding change (#1290) @jafin
• Fixed selector text dropping the nth-child of clause (#1292) @jafin
• Fixed selector text dropping the case-insensitive (#1291) @jafin
• Fixed selector specificity carrying between fields instead of saturating (#1300) @meziantou
• Fixed condition check for disposed state in ReturnToPool (#1296) @meziantou
• Fixed ArgumentOutOfRangeException CSS escapes (#1299) @meziantou
• Fixed whitespace around An+B CSS selector notations (#1297)
• Fixed unsupported pseudo-classes matching everything (#1295)
• Fixed DomException for invalid foreign attribute names such as xml:lang[ (#1294)
• Fixed script data escaped state leaving escaped mode too early (#1298)
• Fixed CurrentScript not indicating the currently executing script (#1308) @lahma
• Fixed returned missing attribute-properties to use empty string instead of null (#1313) @lahma
• Fixed removal of data-* attributes (#1310) @lahma
• Added missing DomName/DomAccessor annotations (#1301) @meziantou
• Added missing DomLiterals attribute to AdjacentPosition (#1311) @lahma
• Released 1.7.3 by @FlorianRappl in #1302

Full Changelog: v1.7.2...v1.7.3

Released on Sunday, August 23 2026

What's Changed

• Fixed matching of annotation-xml encoding to be case-insensitive (#1284) @arpitjain099
• Fixed <xmp> usage in <select> elements
• Added ability to parse immutable byte buffers without a stream (#1286) @dv00d00
• Released 1.7.2 by @FlorianRappl in #1288

New Contributors

• @arpitjain099 made their first contribution in #1284

Full Changelog: 1.7.1...v1.7.2

Released on Wednesday, August 5 2026

• Migrated the build system from NUKE to Fallout by @jafin in #1275
• Improved WHATWG Url specification (#802) @jafin
• Improved tokenizer read performance (#1274) @dv00d00
• Fixed auxiliary browsing context lifetime (#1278) @jafin
• Fixed duplicated DomName attributes on DOM geometry
• Fixed document.open() destroying the DOM tree in case of encoding problems (#1276)
• Fixed source references having wrong line (#1280)
• Released 1.7.1 by @FlorianRappl in #1281

Full Changelog: 1.7.0...v1.7.1

Released on Friday, July 31 2026

• Improved CSS selector performance (#1270, #929) @lahma
• Added support for the :host pseudo selector (#1271)
• Added support for the DomGeometry spec (#1193)

Released on Sunday, July 26 2026

• Improved performance for text tokenization (#1262) @dv00d00
• Improved CSS selector performance
• Improved observer dispatch during HTML parsing (#1266) @dv00d00
• Improved declaration of unsupported pseudo elements
• Fixed inconsistent behavior and segfaults on Android Release build (#1252) @DevGitPit
• Fixed CSS attribute selector modifier handling for i / I (case-insensitive) and s / S (case-sensitive)
• Added API enhancements to expose asynchronous HTML token source (#1265) @dv00d00
• Added bounded stream parsing mode (#1263) @dv00d00
• Added canonicalization of decimal, octal, or hexadecimal IPv4 literals in Url
• Added parsing of / checks for IPv6 literals in Url
• Added support for the CSS column combinator (||) selector syntax
• Added correct identification of CurrentSource in CssMediaElement

Released on Sunday, July 5 2026

• Fixed NodeIterator pre-removing steps to use the first following node (#1260) @ivandrofly
• Fixed Range.IsCollapsed to also compare offsets (#1259) @ivandrofly
• Fixed swapped comparison in Range.CompareBoundaryTo (#1258) @ivandrofly
• Fixed Range.CopyContent to follow the DOM Standard (#1257) @ivandrofly
• Fixed Range.ExtractContent to follow the DOM Standard (#1256) @ivandrofly
• Added missing media attribute change detection on SVG style elements (#1261) @ivandrofly

Released on Saturday, June 13 2026

• Fixed tokenization of large plain-text contents (#1251) @SimonCropp

Released on Saturday, June 6 2026

• Fixed vulnerability via annotation-xml elements (GHSA-pgww-w46g-26qg)
• Updated benchmarks (#1246) @jafin
• Added ability to pass in cookie container to MemoryCookieProvider (#1249) @riina
• Added HTML parser selector optimizations (#1245) @jafin

Released on Wednesday, November 12 2025.

• Fixed handling of carriage return in text sources
• Added support for of syntax in :nth-child functions within CSS selectors
• Added selectedcontent to known elements (#1230)
• Added :open, ::checkmark, ::picker-icon, and ::picker(ident) to selector syntax (#1230)
• Added parsing for customizable <select> (#1230)
• Added .NET 10 as an explicit target

Released on Saturday, November 8 2025.

• Added IReadOnlyList<T> interface to IHtmlCollection, IStringList, ITokenList, IHtmlFormControlsCollection (#1226, #1227) @weitzhandler

Released on Friday, April 18 2025.

• Fixed DOM exposed type of HasChildNodes (#1219) @arekdygas
• Fixed NodeIterator behavior when nodes are removed (#1222)
• Improved form documentation (#1220) @RedZone908
• Updated to NUKE 9 and removed obsolete .NET 6 and 9 targets (#1216) @lahma
• Added GetAttributeNode methods to IElement (#1223) @arekdygas
• Added support for finding targets in browsing contexts (#1218) @TheJayMann
• Added support for targetting iframes (#1205) @TheJayMann

Released on Tuesday, December 31 2024.

• Fixed loading of link element source (#1184) @tomvanenckevort
• Fixed usage of outdated dependency (#1186)
• Fixed cookie Expires recognized as local time (#1212) @noobow34
• Fixed validation for problematic decimal step values (#1210) @rhuebner76
• Removed unnecessary references for .NET 6 and higher (#1187) @lahma
• Removed support for .NET 4.6.1 (least version is 4.6.2)
• Updated to NUKE 8 (#1188) @lahma
• Added new OnToken event for the tokenizer (#1153) @schaakverslaafd
• Added new setting for disabling StringBuilder pooling (#1203) @micahbresette
• Added context to extension methods (#1194) @memiamp
• Added property attribute to meta tags (#1195) @hflexgrig

Released on Friday, March 8 2024.

• Fixed exception when providing wrong response (#1181)
• Fixed handling of various inputs leading to timeouts (#1180)

Released on Friday, March 1 2024.

• Fixed ISourceReference not using HtmlToken underneath
• Fixed handling of replacement characters in escaped script blocks (#1174)
• Fixed handling of empty template element in SVG foreign mode (#1176)
• Fixed handling of <template> in foreign elements (#1179)
• Improved pre-release version to follow semver (#1171) @georg-jung
• Improved NuGet package with link to repository (#1168) @thompson-tomo
• Added PostAsMultipart helper for multipart/form-data to DocumentRequest (#1173)

Released on Thursday, January 18 2024.

• Fixed priority calculations for selector lists (#1161)
• Fixed :where and :is selectors using forgiving lists
• Added option for read only DOM (#1154) @dv00d00
• Added more optimizations to reduce allocation rate (#1159) @dv00d00
• Added support for nested selectors (&)

Released on Friday, November 17 2023.

• Fixed implementation of IRange using offsets (#1147) @zukarusan
• Improved performance in Node.set_Owner (#1149) @campersau
• Added net8.0 as direct target framework

Released on Saturday, November 11 2023.

• Fixed case-sensitiveness in virtual responses
• Fixed warning for outdated actions in CI/CD workflow (#1145) @martincostello
• Fixed AoT warning when trimming (#1144) @martincostello
• Fixed decoding of entities in InnerHtml of <noscript> (#1139)
• Updated PrettyMarkupFormatter to keep new lines on demand (#1131) @dramlian

Released on Tuesday, October 3 2023.

• Improved codebase (#1128, #1126, #1133) @matkoch @ivandrofly
• Improved documentation (#1127)
• Improved child selector performance (#1135) @lahma
• Improved query selector all performance (#584, #1134) @lahma
• Fixed issue with foreign content using end tags
• Fixed typo descendants (#1136) @SimonCropp
• Added a way to resolve symbols by their name to HtmlEntityProvider (#396)

Released on Saturday, June 24 2023.

• Fixed issue with gzip encoding under certain conditions (#1122)
• Fixed issue with li scope leading to stack overflow (#1123)
• Added more pseudo selectors from Selector L4 spec (#1121)

Released on Thursday, June 8 2023.

• Fixed wrong escaping of CSS selector pseudo class functions (#1069)

Released on Tuesday, June 4 2023.

• Improved codebase (#1091, #1090, #1089, #1088, #1087, #1086) @SimonCropp
• Fixed potential stack overflow in GetStyleSheets (#1084) @bjornri
• Fixed serialization of DocumentReadyState by providing DomName attributes (#1109)
• Fixed start and end of Range to handle specific offset in a TextNode (#1118)
• Fixed Range inclusion algorithm (#1119)
• Added public class HtmlTokenizer (#1113)