diff --git a/packages/core/src/parser/model/ParserCss.ts b/packages/core/src/parser/model/ParserCss.ts
index 84f8c6fbc..c9ad2b513 100644
--- a/packages/core/src/parser/model/ParserCss.ts
+++ b/packages/core/src/parser/model/ParserCss.ts
@@ -8,15 +8,19 @@ import { ParserEvents } from '../types';
 const ParserCss = (em?: EditorModel, config: ParserConfig = {}) => ({
   /**
    * Parse CSS string to a desired model object
-   * @param  {String} input CSS string
+   * @param  {String} str CSS string
    * @return {Array<Object>}
    */
-  parse(input: string, opts: { throwOnError?: boolean } = {}) {
+  parse(str: string, opts: { throwOnError?: boolean } = {}) {
     let output: CssRuleJSON[] = [];
     const { parserCss } = config;
     const editor = em?.Editor;
     let nodes: CssRuleJSON[] | ParsedCssRule[] = [];
     let error: unknown;
+    const Parser = em?.Parser;
+    const inputOptions = { input: str };
+    Parser?.__emitEvent(ParserEvents.cssBefore, inputOptions);
+    const { input } = inputOptions;
 
     try {
       nodes = parserCss ? parserCss(input, editor!) : BrowserCssParser(input);
@@ -26,7 +30,7 @@ const ParserCss = (em?: EditorModel, config: ParserConfig = {}) => ({
     }
 
     nodes.forEach((node) => (output = output.concat(this.checkNode(node))));
-    em?.Parser?.__emitEvent(ParserEvents.css, { input, output, nodes, error });
+    Parser?.__emitEvent(ParserEvents.css, { input, output, nodes, error });
 
     return output;
   },
diff --git a/packages/core/src/parser/model/ParserHtml.ts b/packages/core/src/parser/model/ParserHtml.ts
index 96c7b3121..d19edd128 100644
--- a/packages/core/src/parser/model/ParserHtml.ts
+++ b/packages/core/src/parser/model/ParserHtml.ts
@@ -312,6 +312,7 @@ const ParserHtml = (em?: EditorModel, config: ParserConfig & { returnArray?: boo
      */
     parse(str: string, parserCss?: any, opts: HTMLParserOptions = {}) {
       const conf = em?.get('Config') || {};
+      const Parser = em?.Parser;
       const res: HTMLParseResult = { html: [] };
       const cf = { ...config, ...opts };
       const preOptions = {
@@ -325,7 +326,9 @@ const ParserHtml = (em?: EditorModel, config: ParserConfig & { returnArray?: boo
         asDocument: this.__checkAsDocument(str, preOptions),
       };
       const { preParser, asDocument } = options;
-      const input = isFunction(preParser) ? preParser(str, { editor: em?.getEditor()! }) : str;
+      const inputOptions = { input: isFunction(preParser) ? preParser(str, { editor: em?.getEditor()! }) : str };
+      Parser?.__emitEvent(ParserEvents.htmlBefore, inputOptions);
+      const { input } = inputOptions;
       const parseRes = isFunction(cf.parserHtml) ? cf.parserHtml(input, options) : BrowserParserHtml(input, options);
       let root = parseRes as HTMLElement;
       const docEl = parseRes as Document;
@@ -365,7 +368,7 @@ const ParserHtml = (em?: EditorModel, config: ParserConfig & { returnArray?: boo
         if (styleStr) res.css = parserCss.parse(styleStr);
       }
 
-      em?.Parser?.__emitEvent(ParserEvents.htmlRoot, { input, root });
+      Parser?.__emitEvent(ParserEvents.htmlRoot, { input, root });
       let resHtml: HTMLParseResult['html'] = [];
 
       if (asDocument) {
@@ -379,7 +382,7 @@ const ParserHtml = (em?: EditorModel, config: ParserConfig & { returnArray?: boo
       }
 
       res.html = resHtml;
-      em?.Parser?.__emitEvent(ParserEvents.html, { input, output: res, options });
+      Parser?.__emitEvent(ParserEvents.html, { input, output: res, options });
 
       return res;
     },
diff --git a/packages/core/src/parser/types.ts b/packages/core/src/parser/types.ts
index bf1e2bcf3..b9f3839d1 100644
--- a/packages/core/src/parser/types.ts
+++ b/packages/core/src/parser/types.ts
@@ -8,6 +8,17 @@ export enum ParserEvents {
   html = 'parse:html',
   htmlRoot = 'parse:html:root',
 
+  /**
+   * @event `parse:html:before` Event triggered before the HTML parsing starts. An object containing the input is passed as an argument.
+   * @example
+   * editor.on('parse:html:before', (options) => {
+   *   console.log('Parser input', options.input);
+   *   // You can also process the input and update `options.input`
+   *   options.input += '<div>Extra content</div>';
+   * });
+   */
+  htmlBefore = 'parse:html:before',
+
   /**
    * @event `parse:css` On CSS parse, an object containing the input and the output of the parser is passed as an argument.
    * @example
@@ -15,6 +26,17 @@ export enum ParserEvents {
    */
   css = 'parse:css',
 
+  /**
+   * @event `parse:css:before` Event triggered before the CSS parsing starts. An object containing the input is passed as an argument.
+   * @example
+   * editor.on('parse:css:before', (options) => {
+   *   console.log('Parser input', options.input);
+   *   // You can also process the input and update `options.input`
+   *   options.input += '.my-class { color: red; }';
+   * });
+   */
+  cssBefore = 'parse:css:before',
+
   /**
    * @event `parse` Catch-all event for all the events mentioned above. An object containing all the available data about the triggered event is passed as an argument to the callback.
    * @example
diff --git a/packages/core/test/specs/parser/model/ParserCss.ts b/packages/core/test/specs/parser/model/ParserCss.ts
index aa1ce3e4b..c72919b13 100644
--- a/packages/core/test/specs/parser/model/ParserCss.ts
+++ b/packages/core/test/specs/parser/model/ParserCss.ts
@@ -18,16 +18,25 @@ export const CSS_BG_OBJ = {
 
 describe('ParserCss', () => {
   let obj: ReturnType<typeof ParserCss>;
-  let config;
-  let customParser: any;
-  let em = {
-    getCustomParserCss: () => customParser,
-    trigger: () => {},
-  } as unknown as EditorModel;
+  let em: EditorModel;
 
   beforeEach(() => {
-    config = {};
-    obj = ParserCss(em, config);
+    em = new EditorModel({});
+    obj = ParserCss(em, {});
+  });
+
+  afterEach(() => {
+    em.destroy();
+  });
+
+  test('Extend parser input', () => {
+    const str = ' .test1 { color:red; }';
+    const result = {
+      selectors: ['test1'],
+      style: { color: 'red' },
+    };
+    em.on(em.Parser.events.cssBefore, (opts) => (opts.input += str));
+    expect(obj.parse(str)).toEqual([result, result]);
   });
 
   describe('parseSelector', () => {
diff --git a/packages/core/test/specs/parser/model/ParserHtml.ts b/packages/core/test/specs/parser/model/ParserHtml.ts
index c01680be0..53314ec60 100644
--- a/packages/core/test/specs/parser/model/ParserHtml.ts
+++ b/packages/core/test/specs/parser/model/ParserHtml.ts
@@ -6,9 +6,10 @@ import { CSS_BG_OBJ, CSS_BG_STR } from './ParserCss';
 
 describe('ParserHtml', () => {
   let obj: ReturnType<typeof ParserHtml>;
+  let em: Editor;
 
   beforeEach(() => {
-    const em = new Editor({});
+    em = new Editor({});
     const dom = new DomComponents(em);
     obj = ParserHtml(em, {
       textTags: ['br', 'b', 'i', 'u'],
@@ -18,6 +19,19 @@ describe('ParserHtml', () => {
     obj.compTypes = dom.componentTypes;
   });
 
+  afterEach(() => {
+    em.destroy();
+  });
+
+  test('Extend parser input', () => {
+    const str = '<div></div>';
+    const result = { tagName: 'div' };
+    em.on(em.Parser.events.htmlBefore, (opts) => {
+      opts.input += str;
+    });
+    expect(obj.parse(str).html).toEqual([result, result]);
+  });
+
   test('Simple div node', () => {
     const str = '<div></div>';
     const result = [{ tagName: 'div' }];