Read and Write Google Docs Using Apps Script

Apps Script's DocumentApp gives you full programmatic access to Google Docs — reading existing content, inserting new text, formatting paragraphs, and building documents from scratch.

Open a document

// Bound script: opens the doc the script is attached to
const doc = DocumentApp.getActiveDocument();

// Standalone script: open by ID
const doc = DocumentApp.openById('YOUR_DOC_ID');

const body = doc.getBody();

Read all text from a document

function readDocText() {
  const doc = DocumentApp.getActiveDocument();
  const body = doc.getBody();
  const text = body.getText();
  Logger.log(text);
}

Read paragraph by paragraph

function readParagraphs() {
  const body = DocumentApp.getActiveDocument().getBody();
  const paragraphs = body.getParagraphs();

  paragraphs.forEach((p, i) => {
    Logger.log(`Paragraph ${i + 1}: ${p.getText()}`);
  });
}

Append text and paragraphs

function appendContent() {
  const body = DocumentApp.getActiveDocument().getBody();

  body.appendParagraph('New section heading')
      .setHeading(DocumentApp.ParagraphHeading.HEADING2);

  body.appendParagraph(
    'This paragraph was added programmatically by Apps Script.'
  );

  body.appendHorizontalRule();

  Logger.log('Content appended.');
}

Insert text at the top of a document

function insertAtTop() {
  const body = DocumentApp.getActiveDocument().getBody();
  const timestamp = `Report generated: ${new Date().toLocaleString()}`;

  // Insert as the very first paragraph
  body.insertParagraph(0, timestamp)
      .setItalic(true)
      .setForegroundColor('#888888');
}

Format text: bold, italic, font size

function formatText() {
  const body = DocumentApp.getActiveDocument().getBody();
  const para = body.appendParagraph('This is important text.');

  // Get the text element and apply formatting
  const text = para.editAsText();
  text.setBold(0, 7, true);          // Bold "This is"
  text.setFontSize(0, 24, 14);       // Font size 14 for first 24 chars
  text.setForegroundColor(0, 7, '#1a73e8'); // Blue for "This is"
}

Insert and populate a table

function insertTable() {
  const body = DocumentApp.getActiveDocument().getBody();

  const tableData = [
    ['Name', 'Score', 'Grade'],
    ['Alice', '95', 'A'],
    ['Bob',   '82', 'B'],
    ['Carol', '91', 'A'],
  ];

  const table = body.appendTable(tableData);

  // Style the header row
  const headerRow = table.getRow(0);
  for (let i = 0; i < headerRow.getNumCells(); i++) {
    headerRow.getCell(i).setBackgroundColor('#1a73e8')
      .editAsText().setForegroundColor('#ffffff').setBold(true);
  }
}

Search and replace text

function searchAndReplace() {
  const body = DocumentApp.getActiveDocument().getBody();

  body.replaceText('\\{\\{company\\}\\}', 'Acme Corp');
  body.replaceText('\\{\\{date\\}\\}', new Date().toDateString());

  Logger.log('Placeholders replaced.');
}

Clear a document and rewrite it

function rewriteDocument() {
  const body = DocumentApp.getActiveDocument().getBody();
  body.clear();

  body.appendParagraph('Fresh Start')
      .setHeading(DocumentApp.ParagraphHeading.TITLE);

  body.appendParagraph('This document was rewritten by Apps Script.');
  DocumentApp.getActiveDocument().saveAndClose();
}

Tips

body.clear() removes all content but preserves document metadata (title, sharing settings).
replaceText() uses Java regular expressions — escape special characters with \\.
Changes are saved automatically; call doc.saveAndClose() explicitly when done from a standalone script.
Use doc.getUrl() to get a shareable link to the document after creating or modifying it.