API and JSON responses
Turn a Base64 document field from an API response into a PDF you can inspect or save.
KissPDF DECODE BASE64 INTO A PDF
Base64 to PDF Converter
Paste a Base64 string or PDF data URI, convert it into a PDF, preview the document directly in your browser, and download it. Free, private, and no sign-up required.
- Paste raw Base64 or a PDF data URI
- Preview the decoded PDF directly in your browser
- Download the original decoded PDF bytes
- Free, private, and no sign-up required
Base64 PDF inputPaste raw Base64 or a complete PDF data URI
COMMON WORKFLOWS
Convert encoded PDF data into a usable file
Base64-to-PDF decoding is useful when a complete document arrives through a text-oriented system instead of as a normal .pdf attachment.
PDF data URLs
Decode a data:application/pdf;base64 URL copied from HTML, browser storage, or a development tool.
Webhooks and automation
Recover a PDF received as Base64 from an API, webhook, Power Automate flow, Zapier step, or another automation platform.
THREE LOCAL STEPS
How to convert Base64 to PDF
Paste or upload
Paste raw Base64, a PDF data URI, or upload a .txt, .base64, or .b64 file.
Decode and validate
The browser normalizes the text, decodes it off the main thread, and checks the PDF header.
Preview and download
Review the decoded document and download the same validated PDF bytes.
FORMAT REFERENCE
Accepted Base64 PDF formats
The converter accepts standard padded Base64, unpadded Base64, Base64URL characters, line-wrapped text, and complete PDF data URLs. Spaces and line breaks are removed before decoding.
- Raw value example: JVBERi0xLjcK...
- Data URI prefix: data:application/pdf;base64,
- Text uploads: .txt, .base64, and .b64
What validation does—and does not—prove
After decoding, KissPDF looks for the standard %PDF- signature near the beginning of the bytes. This catches text, images, and unrelated Base64 values before download, but it does not repair corruption or guarantee that every page and object is structurally valid.
- Invalid Base64 characters and impossible lengths are rejected
- Non-PDF data URL media types are rejected
- Password protection remains exactly as encoded in the source PDF
Base64 decoding is not decryption
Base64 is a reversible text encoding, not a security mechanism. Anyone who receives the value can decode it. A password-protected PDF remains protected after decoding, while an unprotected PDF gains no confidentiality from Base64.
- Decoded PDF bytes match the encoded source bytes
- No rendering, compression, or PDF rewriting is performed
- Use encryption or PDF password protection for sensitive documents
COMMON QUESTIONS
Frequently Asked Questions
How do I convert Base64 to a PDF file?
Paste the Base64 value, optionally choose an output filename, and click Convert to PDF. After validation, preview the result or download the decoded .pdf file.
How do I convert a Base64 PDF from an API or webhook?
Copy the Base64 document field from the API, JSON response, webhook, Power Automate flow, or other automation output, then paste it into the converter. Remove surrounding JSON quotation marks if present. A complete data:application/pdf;base64, value can be pasted without removing its prefix.
Can I convert a PDF data URI to PDF?
Yes. Paste a complete value beginning with data:application/pdf;base64,. The converter removes the media-type prefix and decodes the remaining Base64 text.
Can I upload a Base64 text file?
Yes. Upload a .txt, .base64, or .b64 file containing raw Base64 or a PDF data URL. The text is read locally in the browser.
Does the converter accept line breaks and missing padding?
Yes. Spaces and line breaks are ignored, and standard equals-sign padding is restored when it can be inferred safely.
Does this decode binary or arbitrary bytes into PDF?
It decodes Base64 text and verifies that the resulting bytes contain a PDF signature. It cannot turn unrelated binary data, an image, or plain text into a valid PDF.
Is Base64 decoding the same as decrypting a PDF?
No. Base64 is reversible encoding, not encryption. If the encoded PDF is password protected, the downloaded PDF still requires that password.
Is my Base64 string uploaded?
No. Normalization, decoding, validation, preview creation, and download all happen in browser memory on your device.
Why does my Base64 value not produce a PDF?
The value may contain invalid characters, use a non-PDF data URL, be incomplete, or decode to bytes without a PDF header. Confirm that the source encoded an actual PDF file.
Will the decoded PDF lose quality?
No. The converter restores the encoded bytes directly and does not render, recompress, or rewrite the PDF.
How large can the decoded PDF be?
The decoded PDF limit is 100 MB on desktop and 32 MB on mobile. The Base64 input is larger than the resulting PDF and also requires browser memory while decoding.