Export Data to CSV in PHP

What is a CSV export

A CSV export lets users download data — a list of orders, students, sales — as a spreadsheet file. CSV is plain text where each line is a row and commas separate columns. Because Excel and Google Sheets open it directly, it is the standard way to hand data to users.

Download headers

These headers, sent before any output, tell the browser to download the response as a file.

<?php
  header("Content-Type: text/csv");
  header('Content-Disposition: attachment; filename="data.csv"');
?>

Content-Type says it is CSV; Content-Disposition: attachment forces a download with the given filename. There must be no output (not even a space) before these.

Writing rows with fputcsv

<?php
  header("Content-Type: text/csv");
  header('Content-Disposition: attachment; filename="data.csv"');

  $out = fopen("php://output", "w");
  fputcsv($out, ["Name", "Marks"]);   // header row
  fputcsv($out, ["Aman", 88]);
  fputcsv($out, ["Diya", 92]);
  fclose($out);
?>

We open php://output (the browser download stream) and write each row with fputcsv, which formats commas and quotes correctly for us.

Exporting from MySQL

<?php
  header("Content-Type: text/csv");
  header('Content-Disposition: attachment; filename="students.csv"');

  $out = fopen("php://output", "w");
  fputcsv($out, ["Name", "Marks"]);   // column titles

  $stmt = $pdo->query("SELECT name, marks FROM students");
  while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
      fputcsv($out, [$row["name"], $row["marks"]]);
  }
  fclose($out);
?>

Write a header row of column names, then loop the database results and write each as a CSV row. The browser downloads a ready-to-open spreadsheet.

Opening in Excel

The downloaded .csv opens directly in Excel or Google Sheets — each comma becomes a column boundary, each line a row. For non-English text, write a UTF-8 BOM first so accents and Hindi display correctly:

<?php
  echo "\xEF\xBB\xBF";  // UTF-8 BOM for Excel
?>

Common mistakes

• Output before the headers. Any space or echo first causes "headers already sent".
• Joining values with commas by hand. Use fputcsv so values with commas or quotes are handled.
• Forgetting the header row. Without column titles the file is hard to read.
• Wrong encoding for Hindi/accents. Add a UTF-8 BOM so Excel shows them correctly.

Summary

• CSV is a plain-text spreadsheet format that opens in Excel.
• Send Content-Type and Content-Disposition headers to force a download.
• Write rows with fputcsv to php://output.
• Export from MySQL by looping results and writing each row.
• Add a UTF-8 BOM for correct Hindi/accented text in Excel.

Next, read the data first with PHP CRUD, or connect safely with PHP MySQL connection.