--- title: "monaco-editor Breaking Changes on npm | Since.dev" description: "What each monaco-editor release removed, renamed or changed: 354 breaking changes in 5 versions on npm, each with its source." canonical_url: https://since.dev/packages/npm/monaco-editor last_updated: 2026-07-20 --- # monaco-editor breaking changes Every breaking API change we have recorded in monaco-editor on npm: 354 breaking changes in 5 versions. Below are its newest 5 versions, removals and renames first, each with its source. Newest change July 20, 2026 ## 0.56.0 141 breaking changes, first published July 20, 2026. - **Removed** `createWebWorker` createWebWorker was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `css` css was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `editor.IOverlayWidgetPosition.stackOridinal` IOverlayWidgetPosition.stackOridinal was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `html` html was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `IWebWorkerOptions` IWebWorkerOptions was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `json` json was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `languages.InlineCompletionHint` languages.InlineCompletionHint was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `lsp` lsp was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Removed** `typescript` typescript was removed in monaco-editor 0.56.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.56.0) - **Default changed** The release sets auto reload to false by default. Code that relied on automatic reloading must now enable it explicitly. [github.com](https://github.com/microsoft/monaco-editor/releases/tag/v0.56.0) And 131 more in this version. ## 0.55.0 122 breaking changes, first published November 20, 2025. - **Removed** `editor.IWebWorkerOptions` editor.IWebWorkerOptions was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.CSSDataConfiguration` languages.css.CSSDataConfiguration was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.CSSDataV1` languages.css.CSSDataV1 was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.cssDefaults` languages.css.cssDefaults was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.CSSFormatConfiguration` languages.css.CSSFormatConfiguration was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.DiagnosticsOptions` languages.css.DiagnosticsOptions was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.EntryStatus` languages.css.EntryStatus was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.IAtDirectiveData` languages.css.IAtDirectiveData was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.IPropertyData` languages.css.IPropertyData was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) - **Removed** `languages.css.IPseudoClassData` languages.css.IPseudoClassData was removed in monaco-editor 0.55.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.55.0) And 112 more in this version. ## 0.54.0 89 breaking changes, first published October 6, 2025. - **Removed** `MonacoEnvironment` MonacoEnvironment was removed in monaco-editor 0.54.0 [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.colorDecoratorsActivatedOn` Was colorDecoratorsActivatedOn = 167; now colorDecoratorsActivatedOn = 168. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.defaultColorDecorators` Was defaultColorDecorators = 166; now defaultColorDecorators = 167. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.definitionLinkOpensInPeek` Was definitionLinkOpensInPeek = 100; now definitionLinkOpensInPeek = 101. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.editorClassName` Was editorClassName = 161; now editorClassName = 162. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.effectiveAllowVariableFonts` Was effectiveAllowVariableFonts = 171; now effectiveAllowVariableFonts = 172. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.effectiveCursorStyle` Was effectiveCursorStyle = 160; now effectiveCursorStyle = 161. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.effectiveEditContext` Was effectiveEditContext = 169; now effectiveEditContext = 170. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.inertialScroll` Was inertialScroll = 157; now inertialScroll = 158. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) - **Signature changed** `editor.EditorOption.inlayHints` Was inlayHints = 158; now inlayHints = 159. [npmjs.com](https://www.npmjs.com/package/monaco-editor/v/0.54.0) And 79 more in this version. ## 0.54.0-dev-20250928 1 breaking change, first published October 6, 2025. - **Behavior changed** The ESM build now adds .js extensions to its file names. Code that imports the ESM files by their extensionless paths may need to add the .js extension. [github.com](https://github.com/microsoft/monaco-editor/releases/tag/v0.54.0-dev-20250928) ## 0.54.0-dev-20250911 1 breaking change, first published October 6, 2025. - **Removed** `out.languages` The out/languages output is no longer available, so code that imports from it will fail. Import the language modules from another path or entry point. [github.com](https://github.com/microsoft/monaco-editor/releases/tag/v0.54.0-dev-20250911) ## Check your code These are the changes. To see which of them reach your code, [scan a public repository](https://since.dev/scan.md), or have your coding agent call `check_code` with your manifest or lockfile over [MCP](https://since.dev/docs.md#mcp). [The API](https://since.dev/docs.md#api) reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys. ## Put your code on continuous management. Scan a public repository now, or give your agent one line. ### See how out of date your code is. [Scan a repository](https://since.dev/scan.md). Any public GitHub repository. No sign-in. ### Tell your agent what changed since it was trained. `claude mcp add --transport http since https://api.since.dev/mcp` --- Every page on this site as Markdown: https://since.dev/sitemap.md. For agents: https://since.dev/llms.txt.