In today's digital world, PDF documents are one of the most commonly used file formats for sharing information. Whether you're generating invoices, reports, certificates, receipts, or downloadable documents from your website, PDFs provide a professional and secure way to present content.

If you're a PHP developer, one of the easiest and most reliable ways to generate PDF files is by using the mPDF library. It allows you to convert HTML and CSS into high-quality PDF documents with minimal effort.

In this guide, you'll learn How to Create PDF File from Webpage Using PHP and mPDF with clear explanations, installation steps, example code, customization tips, and best practices.

 

What is mPDF?

mPDF is a popular open-source PHP library that converts HTML pages into PDF documents. Instead of manually creating PDFs from scratch, developers can simply write HTML and CSS, and mPDF transforms it into a downloadable PDF.

Because it understands HTML and CSS, developers can design documents just like web pages while maintaining a professional appearance.

Some common uses include:

• Invoice generation

• Sales reports

• Employee payslips

• Certificates

• Product catalogs

• Order summaries

• Medical reports

• School report cards

• Event tickets

• Legal documents

 

Why Use mPDF for PDF Generation?

There are several PHP libraries available for generating PDFs, but mPDF remains one of the most developer-friendly solutions.

Some major advantages include:

Easy Installation

You can install it quickly using Composer without complicated setup.

HTML and CSS Support

Most HTML elements and CSS properties are supported, making document design simple.

Unicode Support

mPDF supports multiple languages, making it suitable for international applications.

Images and Tables

You can include:

• Images

• Logos

• Tables

• Background colors

• Borders

• Headers

• Footers

Custom Page Sizes

Generate documents in:

• A4

• Letter

• Legal

• Custom dimensions

Password Protection

Secure PDFs with passwords and permissions.

 

Requirements Before You Start

Before creating PDFs, ensure you have:

• PHP 7.4 or above

• Composer installed

• Basic PHP knowledge

• Local server (XAMPP, WAMP, MAMP, or Laragon)

• HTML and CSS understanding

 

Step 1: Install mPDF Using Composer

Open your terminal inside your project directory and run:

composer require mpdf/mpdf

 

Composer automatically downloads the library and installs all required dependencies.

After installation, your project structure will include:

project/

?

??? vendor/

??? composer.json

??? composer.lock

??? index.php

 

 

Step 2: Include Composer Autoload

Inside your PHP file:

require_once __DIR__ . '/vendor/autoload.php';

 

This loads the mPDF library automatically.

 

Step 3: Create a New mPDF Object

Now create an instance of mPDF.

$mpdf = new \Mpdf\Mpdf();

 

This initializes the PDF generator.

 

Step 4: Write HTML Content

You can write HTML directly.

$html = '

 

Invoice

 

 

 

Customer Name: John

 

 

 

Total Amount: $150

 

';

 

You can use:

• Tables

• Images

• Paragraphs

• Headings

• Lists

• Inline CSS

 

Step 5: Convert HTML into PDF

Now send the HTML to mPDF.

$mpdf->WriteHTML($html);

 

The library converts the HTML into PDF format automatically.

 

Step 6: Output the PDF

Finally, display or download the PDF.

$mpdf->Output();

 

When executed, the browser opens the generated PDF.

 

Complete Example

Below is a complete PHP example.

 

require_once __DIR__ . '/vendor/autoload.php';

 

$mpdf = new \Mpdf\Mpdf();

 

$html = '

 

 

Invoice

 

 

 

---

 

 

 

Name : John Doe

 

 

 

Email : john@example.com

 

 

 

Total : $250

 

 

';

 

$mpdf->WriteHTML($html);

 

$mpdf->Output();

 

?>

 

This example creates a simple invoice PDF.

 

How to Generate PDF from an Existing Webpage

Instead of writing HTML manually, you can capture the HTML of an existing webpage.

Example:

ob_start();

 

include 'invoice.php';

 

$html = ob_get_clean();

 

$mpdf = new \Mpdf\Mpdf();

 

$mpdf->WriteHTML($html);

 

$mpdf->Output();

 

This technique is widely used in real-world applications.

Examples include:

• Invoice pages

• Salary slips

• Reports

• Purchase orders

• Certificates

 

Download PDF Instead of Opening It

To force the PDF to download:

$mpdf->Output('invoice.pdf', 'D');

 

The "D" parameter tells the browser to download the file.

 

Save PDF on the Server

If you want to save the file instead of displaying it:

$mpdf->Output('reports/report.pdf','F');

 

This stores the PDF inside the specified folder.

Useful for:

• Automated reports

• Monthly invoices

• Employee documents

• Backup copies

 

Add CSS Styling

mPDF supports external CSS.

Example:

$stylesheet = file_get_contents('style.css');

 

$mpdf->WriteHTML($stylesheet,1);

 

$mpdf->WriteHTML($html,2);

 

This allows your PDFs to look similar to your website.

 

Add Images

Example:

 

Images supported include:

• JPG

• PNG

• GIF

• SVG

 

Add Headers and Footers

Example:

$mpdf->SetHeader('Company Name');

 

$mpdf->SetFooter('{PAGENO}');

 

Now every page contains:

• Company header

• Page number footer

 

Add Watermark

Example:

$mpdf->SetWatermarkText('CONFIDENTIAL');

 

$mpdf->showWatermarkText = true;

 

Perfect for:

• Internal reports

• Confidential documents

• Draft versions

 

Password Protect PDF

You can restrict access.

Example:

$mpdf->SetProtection(

[],

'user123',

'owner123'

);

 

Useful for:

• Salary slips

• Medical reports

• Confidential contracts

 

Common Use Cases of mPDF

Businesses use mPDF for many applications, including:

• Invoice generation

• GST bills

• Purchase orders

• Shipping labels

• Quotations

• Employee payslips

• ID cards

• Event tickets

• Hotel booking confirmations

• Medical prescriptions

• Student certificates

• Mark sheets

• Reports

• Legal documents

 

Best Practices While Using mPDF

To achieve better performance and maintainability:

• Keep HTML clean and semantic.

• Use external CSS instead of inline styles where possible.

• Optimize images before embedding them.

• Avoid excessive nested tables.

• Test layouts with large datasets.

• Use Unicode fonts for multilingual PDFs.

• Store reusable templates separately.

• Handle errors gracefully during PDF generation.

• Keep the mPDF package updated.

• Use Composer to manage dependencies.

 

Common Errors and Their Solutions

Class Not Found

Cause:

Composer autoload is missing.

Solution:

require_once 'vendor/autoload.php';

 

 

Blank PDF

Possible reasons include:

• Empty HTML content

• PHP errors before output

• Invalid HTML structure

Check your HTML carefully before generating the PDF.

 

Images Not Showing

Ensure:

• The image path is correct.

• The file exists.

• File permissions are appropriate.

• Use absolute paths if necessary.

 

CSS Not Applied

Verify:

• CSS file path is correct.

• The stylesheet is loaded before HTML.

• Unsupported CSS properties are not being used.

 

Advantages of Using mPDF

Developers prefer mPDF because it offers:

• Free and open-source

• Easy integration with PHP

• Excellent HTML support

• CSS compatibility

• Unicode language support

• Fast document generation

• Custom headers and footers

• Password protection

• Watermarks

• Flexible page settings

• Active community support

These features make mPDF an ideal solution for both small websites and enterprise-level PHP applications.

 

Conclusion

Creating PDF documents from web pages is an essential feature for many PHP applications, and mPDF makes the process straightforward and efficient. By converting HTML and CSS directly into professional-quality PDFs, developers can generate invoices, reports, certificates, receipts, and many other document types without building complex PDF layouts manually.

By following the steps covered in this guide on How to Create PDF File from Webpage Using PHP and mPDF, you can install the library, generate PDFs from HTML, apply custom styling, add headers, footers, images, and watermarks, and even secure your documents with password protection.

Whether you're building an eCommerce platform, school management system, CRM, ERP, or any custom PHP application, mPDF provides a reliable, flexible, and scalable solution for PDF generation. With proper coding practices and optimized templates, you can deliver professional documents that enhance both user experience and business workflows.

FAQ

1. How do I get the last insert ID in PHP CodeIgniter?

In CodeIgniter 4, you can use the insertID() method after inserting a record. If you're using a model, you can retrieve it with getInsertID(). In CodeIgniter 3, use $this->db->insert_id() to get the last auto-increment ID.

2. What is the purpose of the last insert ID in CodeIgniter?

The last insert ID helps you retrieve the auto-generated primary key of the newly inserted record. It is commonly used to create relationships between tables, such as linking users with profiles, orders with order items, or products with images.

3. What is the difference between insertID() and getInsertID() in CodeIgniter?

insertID() is used with the database connection object, while getInsertID() is used when inserting data through a CodeIgniter Model. Both methods return the ID of the most recently inserted record.

4. How do I get the last insert ID in CodeIgniter 3?

After inserting a record using $this->db->insert(), simply call $this->db->insert_id() to retrieve the last generated auto-increment ID from the database.

5. Can I retrieve the last insert ID after using insertBatch()?

No. The insertBatch() method inserts multiple records at once but does not return all generated IDs. If you need each inserted ID, you'll need to insert records individually or use a custom solution.

6. Does insertID() work with MySQL databases?

Yes. The insertID() method works perfectly with MySQL and other supported database systems that use auto-increment primary keys, provided the table is configured correctly.

7. Is it safe to use the last insert ID inside database transactions?

Yes. Using insertID() within a database transaction is a recommended practice when inserting related records into multiple tables. It ensures data consistency and helps maintain proper relationships.

8. Why is my insertID() returning 0 or NULL?

This usually happens if the insert operation fails, the table doesn't have an auto-increment column, or you're calling insertID() before executing the insert query. Always check that the insert was successful before retrieving the ID.

9. Can I use the last insert ID for foreign key relationships?

Absolutely. One of the most common uses of the last insert ID is storing it as a foreign key in another table, such as linking an order to its order items or a user to their profile.

10. Which method is recommended for getting the last insert ID in CodeIgniter 4?

The recommended approach is to use $db->insertID() when working with the Query Builder or $model->getInsertID() when using Models. Both methods are simple, reliable, and follow CodeIgniter 4 best practices.