Base64 to PDF Converter
Convert Base64 encoded strings to PDF files with preview and download options.
Where Base64-encoded PDFs come from
REST API responses
Many document-generation and e-signature APIs (invoicing, contracts, reports) return the PDF as a Base64 string inside a JSON field rather than a raw file.
Data URIs
A string starting with data:application/pdf;base64,... embedded directly in HTML, CSS, or a database column. This tool strips that prefix automatically.
Email/webhook payloads
Some webhook and email-parsing services attach PDFs as Base64 text fields since raw binary isn't always transportable in JSON.
If conversion fails
"Invalid Base64 string or not a valid PDF"
Make sure you copied the full string with no truncation — Base64 PDFs are often thousands of characters long, and partial copies fail to decode.
String includes surrounding quotes
If you copied straight from a JSON response like "data": "JVBERi0x...", remove the outer quotes before pasting — they aren't part of the encoded data.
Extra prefix text
Some tools prepend the mime type differently, e.g. data:application/octet-stream;base64,. Strip anything before the actual base64 characters if conversion fails.
How it works
Paste Base64
Copy your Base64 encoded PDF string into the input box.
Convert
Click "Convert to PDF" to decode and generate the PDF file.
Download
Preview the PDF or download it to your computer.
Common use cases
API Response Handling
Convert Base64 PDF data from API responses to downloadable files.
Email Attachments
Decode Base64 encoded PDF attachments from emails or APIs.
Data Processing
Convert Base64 PDF strings from databases or data exports.
Testing & Development
Test PDF generation by converting Base64 strings during development.
Frequently asked questions
Is my Base64 data stored or sent to a server?
No. All Base64 to PDF conversion happens entirely in your browser using JavaScript. Your data never leaves your computer, ensuring complete privacy and security.
What is Base64 encoding?
Base64 is a way to encode binary data (like PDFs) as text. It is commonly used in APIs and data transmission.
Can I convert large PDFs?
Yes, but very large Base64 strings (>10MB) may slow down your browser depending on device capabilities.
What if the conversion fails?
The tool will show an error if the Base64 string is invalid or does not represent a valid PDF file.
Can I preview the PDF before downloading?
Yes, the tool shows a preview of the PDF after conversion. You can then download it if needed.
Can I use this tool offline?
Yes, once the page loads, the tool works completely offline since all processing happens in your browser.