List Files in a Google Drive Folder

Apps Script lets you iterate over all files in a Drive folder using DriveApp.getFolderById() and .getFiles(). This is useful for generating file inventories, auditing contents, or writing file metadata back to a Google Sheet.

Listing All Files in a Folder

function listFilesInFolder() {
  var folder = DriveApp.getFolderById("YOUR_FOLDER_ID");
  var files = folder.getFiles();

  while (files.hasNext()) {
    var file = files.next();
    Logger.log(file.getName() + " | " + file.getMimeType() + " | " + file.getDateCreated());
  }
}

Writing File List to a Sheet

This example scans the North - Sales Reports folder and writes a file inventory to a new sheet tab:

function exportFileInventoryToSheet() {
  var folder = DriveApp.getFolderById("YOUR_NORTH_FOLDER_ID");
  var files = folder.getFiles();

  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName("File Inventory") || ss.insertSheet("File Inventory");
  sheet.clearContents();

  sheet.appendRow(["File Name", "Type", "Size (bytes)", "Created", "URL"]);

  while (files.hasNext()) {
    var file = files.next();
    sheet.appendRow([
      file.getName(),
      file.getMimeType(),
      file.getSize(),
      file.getDateCreated(),
      file.getUrl()
    ]);
  }

  Logger.log("Inventory written to sheet.");
}

Listing Files Across All Region Subfolders

This iterates over each region subfolder under a parent and builds a combined inventory:

function listAllRegionFiles() {
  var parentFolder = DriveApp.getFolderById("YOUR_ROOT_FOLDER_ID");
  var subfolders = parentFolder.getFolders();

  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName("All Files") || ss.insertSheet("All Files");
  sheet.clearContents();
  sheet.appendRow(["Region", "File Name", "Created", "URL"]);

  while (subfolders.hasNext()) {
    var subfolder = subfolders.next();
    var files = subfolder.getFiles();

    while (files.hasNext()) {
      var file = files.next();
      sheet.appendRow([
        subfolder.getName(),
        file.getName(),
        file.getDateCreated(),
        file.getUrl()
      ]);
    }
  }

  Logger.log("Done listing all regional files.");
}

With the Acme Corp folder structure, this produces a consolidated view of every sales report across North, East, South, and West — sorted by region.

Filtering Files by Type

To list only PDFs or Google Sheets within a folder:

function listPDFsOnly() {
  var folder = DriveApp.getFolderById("YOUR_FOLDER_ID");
  var files = folder.getFilesByType(MimeType.PDF);

  while (files.hasNext()) {
    var file = files.next();
    Logger.log("PDF: " + file.getName());
  }
}

Common MIME types: MimeType.PDF, MimeType.GOOGLE_SHEETS, MimeType.GOOGLE_DOCS, MimeType.CSV.