diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index ceeb9684..16da6f8f 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - `Fix` - Create a new block when clicked at the bottom [#1588](https://github.com/codex-team/editor.js/issues/1588).
 - `Fix` — Fix sanitisation problem with Inline Tools [#1631](https://github.com/codex-team/editor.js/issues/1631)
+- `Fix` — Fix copy in FireFox [1625](https://github.com/codex-team/editor.js/issues/1625)
 - `Refactoring` - The Sanitizer module is util now.
 - `Refactoring` - Tooltip module is util now.
 - `Refactoring` — Refactoring based on LGTM [#1577](https://github.com/codex-team/editor.js/issues/1577).
diff --git a/src/components/block/index.ts b/src/components/block/index.ts
index 7afedca2..4d65bdc4 100644
--- a/src/components/block/index.ts
+++ b/src/components/block/index.ts
@@ -504,7 +504,7 @@ export default class Block {
     /**
      * call Tool's method with the instance context
      */
-    if (this.toolInstance[methodName] && this.toolInstance[methodName] instanceof Function) {
+    if (_.isFunction(this.toolInstance[methodName])) {
       if (methodName === BlockToolAPI.APPEND_CALLBACK) {
         _.log(
           '`appendCallback` hook is deprecated and will be removed in the next major release. ' +
diff --git a/src/components/modules/blockEvents.ts b/src/components/modules/blockEvents.ts
index 89cd5077..e7f9336c 100644
--- a/src/components/modules/blockEvents.ts
+++ b/src/components/modules/blockEvents.ts
@@ -167,7 +167,7 @@ export default class BlockEvents extends Module {
    *
    * @param {ClipboardEvent} event - clipboard event
    */
-  public handleCommandC(event: ClipboardEvent): Promise<void> {
+  public handleCommandC(event: ClipboardEvent): void {
     const { BlockSelection } = this.Editor;
 
     if (!BlockSelection.anyBlockSelected) {
@@ -175,7 +175,7 @@ export default class BlockEvents extends Module {
     }
 
     // Copy Selected Blocks
-    return BlockSelection.copySelectedBlocks(event);
+    BlockSelection.copySelectedBlocks(event);
   }
 
   /**
@@ -183,21 +183,26 @@ export default class BlockEvents extends Module {
    *
    * @param {ClipboardEvent} event - clipboard event
    */
-  public async handleCommandX(event: ClipboardEvent): Promise<void> {
+  public handleCommandX(event: ClipboardEvent): void {
     const { BlockSelection, BlockManager, Caret } = this.Editor;
 
     if (!BlockSelection.anyBlockSelected) {
       return;
     }
 
-    await BlockSelection.copySelectedBlocks(event);
+    BlockSelection.copySelectedBlocks(event).then(() => {
+      const selectionPositionIndex = BlockManager.removeSelectedBlocks();
 
-    const selectionPositionIndex = BlockManager.removeSelectedBlocks();
+      /**
+       * Insert default block in place of removed ones
+       */
+      const insertedBlock = BlockManager.insertDefaultBlockAtIndex(selectionPositionIndex, true);
 
-    Caret.setToBlock(BlockManager.insertDefaultBlockAtIndex(selectionPositionIndex, true), Caret.positions.START);
+      Caret.setToBlock(insertedBlock, Caret.positions.START);
 
-    /** Clear selection */
-    BlockSelection.clearSelection(event);
+      /** Clear selection */
+      BlockSelection.clearSelection(event);
+    });
   }
 
   /**
diff --git a/src/components/modules/blockSelection.ts b/src/components/modules/blockSelection.ts
index 96ada11b..682b7aeb 100644
--- a/src/components/modules/blockSelection.ts
+++ b/src/components/modules/blockSelection.ts
@@ -286,7 +286,7 @@ export default class BlockSelection extends Module {
    *
    * @returns {Promise<void>}
    */
-  public async copySelectedBlocks(e: ClipboardEvent): Promise<void> {
+  public copySelectedBlocks(e: ClipboardEvent): Promise<void> {
     /**
      * Prevent default copy
      */
@@ -305,15 +305,22 @@ export default class BlockSelection extends Module {
       fakeClipboard.appendChild(fragment);
     });
 
-    const savedData = await Promise.all(this.selectedBlocks.map((block) => block.save()));
-
     const textPlain = Array.from(fakeClipboard.childNodes).map((node) => node.textContent)
       .join('\n\n');
     const textHTML = fakeClipboard.innerHTML;
 
     e.clipboardData.setData('text/plain', textPlain);
     e.clipboardData.setData('text/html', textHTML);
-    e.clipboardData.setData(this.Editor.Paste.MIME_TYPE, JSON.stringify(savedData));
+
+    return Promise
+      .all(this.selectedBlocks.map((block) => block.save()))
+      .then(savedData => {
+        try {
+          e.clipboardData.setData(this.Editor.Paste.MIME_TYPE, JSON.stringify(savedData));
+        } catch (err) {
+          // In Firefox we can't set data in async function
+        }
+      });
   }
 
   /**
diff --git a/test/cypress/support/commands.ts b/test/cypress/support/commands.ts
index 7b8f8da0..fc829c09 100644
--- a/test/cypress/support/commands.ts
+++ b/test/cypress/support/commands.ts
@@ -62,3 +62,55 @@ Cypress.Commands.add('paste', {
 
   return subject;
 });
+
+/**
+ * Copy command to dispatch copy event on subject
+ *
+ * @usage
+ * cy.get('div').copy().then(data => {})
+ */
+Cypress.Commands.add('copy', { prevSubject: true }, async (subject) => {
+  const clipboardData: {[type: string]: any} = {};
+
+  const copyEvent = Object.assign(new Event('copy', {
+    bubbles: true,
+    cancelable: true,
+  }), {
+    clipboardData: {
+      setData: (type: string, data: any): void => {
+        console.log(type, data);
+        clipboardData[type] = data;
+      },
+    },
+  });
+
+  subject[0].dispatchEvent(copyEvent);
+
+  return clipboardData;
+});
+
+/**
+ * Cut command to dispatch cut event on subject
+ *
+ * @usage
+ * cy.get('div').cut().then(data => {})
+ */
+Cypress.Commands.add('cut', { prevSubject: true }, async (subject) => {
+  const clipboardData: {[type: string]: any} = {};
+
+  const copyEvent = Object.assign(new Event('cut', {
+    bubbles: true,
+    cancelable: true,
+  }), {
+    clipboardData: {
+      setData: (type: string, data: any): void => {
+        console.log(type, data);
+        clipboardData[type] = data;
+      },
+    },
+  });
+
+  subject[0].dispatchEvent(copyEvent);
+
+  return clipboardData;
+});
diff --git a/test/cypress/support/index.d.ts b/test/cypress/support/index.d.ts
index f675962a..7d83933e 100644
--- a/test/cypress/support/index.d.ts
+++ b/test/cypress/support/index.d.ts
@@ -24,6 +24,22 @@ declare global {
        * @param data - map with MIME type as a key and data as value
        */
       paste(data: {[type: string]: string}): Chainable<Subject>
+
+      /**
+       * Copy command to dispatch copy event on subject
+       *
+       * @usage
+       * cy.get('div').copy().then(data => {})
+       */
+      copy(): Chainable<{ [type: string]: any }>;
+
+      /**
+       * Cut command to dispatch cut event on subject
+       *
+       * @usage
+       * cy.get('div').cut().then(data => {})
+       */
+      cut(): Chainable<{ [type: string]: any }>;
     }
 
     interface ApplicationWindow {
diff --git a/test/cypress/tests/copy-paste.spec.ts b/test/cypress/tests/copy-paste.spec.ts
new file mode 100644
index 00000000..97f6a0ec
--- /dev/null
+++ b/test/cypress/tests/copy-paste.spec.ts
@@ -0,0 +1,274 @@
+import Header from '../../../example/tools/header';
+import Image from '../../../example/tools/simple-image';
+import * as _ from '../../../src/components/utils';
+
+describe('Copy pasting from Editor', () => {
+  beforeEach(() => {
+    if (this && this.editorInstance) {
+      this.editorInstance.destroy();
+    } else {
+      cy.createEditor({
+        tools: {
+          header: Header,
+          image: Image,
+        },
+      }).as('editorInstance');
+    }
+  });
+
+  context('pasting', () => {
+    it('should paste plain text', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/plain': 'Some plain text',
+        })
+        .should('contain', 'Some plain text');
+    });
+
+    it('should paste inline html data', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/html': '<p><b>Some text</b></p>',
+        })
+        .should('contain.html', '<b>Some text</b>');
+    });
+
+    it('should paste several blocks if plain text contains new lines', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/plain': 'First block\n\nSecond block',
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .then(blocks => {
+          expect(blocks[0].textContent).to.eq('First block');
+          expect(blocks[1].textContent).to.eq('Second block');
+        });
+    });
+
+    it('should paste several blocks if html contains several paragraphs', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/html': '<p>First block</p><p>Second block</p>',
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .then(blocks => {
+          expect(blocks[0].textContent).to.eq('First block');
+          expect(blocks[1].textContent).to.eq('Second block');
+        });
+    });
+
+    it('should paste using custom data type', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'application/x-editor-js': JSON.stringify([
+            {
+              tool: 'paragraph',
+              data: {
+                text: 'First block',
+              },
+            },
+            {
+              tool: 'paragraph',
+              data: {
+                text: 'Second block',
+              },
+            },
+          ]),
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .then(blocks => {
+          expect(blocks[0].textContent).to.eq('First block');
+          expect(blocks[1].textContent).to.eq('Second block');
+        });
+    });
+
+    it('should parse block tags', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/html': '<h2>First block</h2><p>Second block</p>',
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .get('h2.ce-header')
+        .should('contain', 'First block');
+
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-paragraph')
+        .should('contain', 'Second block');
+    });
+
+    it('should parse pattern', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .paste({
+          'text/plain': 'https://codex.so/public/app/img/external/codex2x.png',
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .get('img')
+        .should('have.attr', 'src', 'https://codex.so/public/app/img/external/codex2x.png');
+    });
+  });
+
+  context('copying', () => {
+    it('should copy inline fragment', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .type('Some text{selectall}')
+        .copy()
+        .then(clipboardData => {
+          /**
+           * As no blocks selected, clipboard data will be empty as will be handled by browser
+           */
+          expect(clipboardData).to.be.empty;
+        });
+    });
+
+    it('should copy several blocks', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .type('First block{enter}');
+
+      cy.get('[data-cy=editorjs')
+        .get('div.ce-block')
+        .next()
+        .type('Second block')
+        .type('{movetostart}')
+        .trigger('keydown', {
+          shiftKey: true,
+          keyCode: _.keyCodes.UP,
+        })
+        .copy()
+        .then(clipboardData => {
+          expect(clipboardData['text/html']).to.eq('<p>First block</p><p>Second block</p>');
+          expect(clipboardData['text/plain']).to.eq(`First block\n\nSecond block`);
+
+          /**
+           * Need to wait for custom data as it is set asynchronously
+           */
+          // eslint-disable-next-line cypress/no-unnecessary-waiting
+          cy.wait(0).then(() => {
+            expect(clipboardData['application/x-editor-js']).not.to.be.undefined;
+
+            const data = JSON.parse(clipboardData['application/x-editor-js']);
+
+            expect(data[0].tool).to.eq('paragraph');
+            expect(data[0].data).to.deep.eq({ text: 'First block' });
+            expect(data[1].tool).to.eq('paragraph');
+            expect(data[1].data).to.deep.eq({ text: 'Second block' });
+          });
+        });
+    });
+  });
+
+  context('cutting', () => {
+    it('should cut inline fragment', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .type('Some text{selectall}')
+        .cut()
+        .then(clipboardData => {
+          /**
+           * As no blocks selected, clipboard data will be empty as will be handled by browser
+           */
+          expect(clipboardData).to.be.empty;
+        });
+    });
+
+    it('should cut several blocks', () => {
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .click()
+        .type('First block{enter}');
+
+      cy.get('[data-cy=editorjs')
+        .get('div.ce-block')
+        .next()
+        .type('Second block')
+        .type('{movetostart}')
+        .trigger('keydown', {
+          shiftKey: true,
+          keyCode: _.keyCodes.UP,
+        })
+        .cut()
+        .then(clipboardData => {
+          expect(clipboardData['text/html']).to.eq('<p>First block</p><p>Second block</p>');
+          expect(clipboardData['text/plain']).to.eq(`First block\n\nSecond block`);
+
+          /**
+           * Need to wait for custom data as it is set asynchronously
+           */
+          // eslint-disable-next-line cypress/no-unnecessary-waiting
+          cy.wait(0).then(() => {
+            expect(clipboardData['application/x-editor-js']).not.to.be.undefined;
+
+            const data = JSON.parse(clipboardData['application/x-editor-js']);
+
+            expect(data[0].tool).to.eq('paragraph');
+            expect(data[0].data).to.deep.eq({ text: 'First block' });
+            expect(data[1].tool).to.eq('paragraph');
+            expect(data[1].data).to.deep.eq({ text: 'Second block' });
+          });
+        });
+
+      cy.get('[data-cy=editorjs]')
+        .should('not.contain', 'First block')
+        .should('not.contain', 'Second block');
+    });
+
+    it('should cut lots of blocks', () => {
+      const numberOfBlocks = 50;
+
+      for (let i = 0; i < numberOfBlocks; i++) {
+        cy.get('[data-cy=editorjs]')
+          .get('div.ce-block')
+          .last()
+          .click()
+          .type(`Block ${i}{enter}`);
+      }
+
+      cy.get('[data-cy=editorjs]')
+        .get('div.ce-block')
+        .first()
+        .click()
+        .type('{ctrl+A}')
+        .type('{ctrl+A}')
+        .cut()
+        .then((clipboardData) => {
+          /**
+           * Need to wait for custom data as it is set asynchronously
+           */
+          // eslint-disable-next-line cypress/no-unnecessary-waiting
+          cy.wait(0).then(() => {
+            expect(clipboardData['application/x-editor-js']).not.to.be.undefined;
+
+            const data = JSON.parse(clipboardData['application/x-editor-js']);
+
+            expect(data.length).to.eq(numberOfBlocks + 1);
+          });
+        });
+    });
+  });
+});