Open and save a PDF file in Flutter PDF

10 Jul 20261 minute to read

Opening an existing PDF document

You can open an existing PDF document by using the PdfDocument class. The following example shows how to load an existing document from the list of bytes.

dart

import 'dart:io';
//Opens an existing document from the list of bytes
PdfDocument document =
    PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());

Opening an existing PDF document from the Base64 string

You can open an existing document from the Base64 string by using the PdfDocument class as shown below.

dart

//Opens an existing document from the Base64 string
PdfDocument document = PdfDocument.fromBase64String(
    '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');

Saving a PDF document to a list of bytes

You can save the manipulated PDF document as a list of bytes using the save method of PdfDocument class. Also, you can save the list of bytes to the file system as follows.

dart

//Opens an existing PDF document
PdfDocument document =
    PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());

//Saves the document into a list of bytes
List<int> bytes =await document.save();

//Saves the bytes to the file system
File('output.pdf').writeAsBytes(bytes);