KissPDF Encode PDF as Base64
Convert a PDF file to a Base64-encoded string directly in your browser. Copy raw Base64 for APIs and JSON, or create a PDF data URL (data URI) for HTML embedding. The original PDF bytes stay unchanged and are never uploaded.
Base64 represents binary PDF bytes as a plain-text string. It is useful when an API, JSON payload, SOAP request, database field, or HTML document needs to carry a complete PDF.
The PDF is encoded directly in browser memory. No document is uploaded, and decoding the result produces the same source bytes.
Choose one PDF, select the output format, then copy or download the complete encoded value.
Select a local PDF file or drop it onto the upload area.
KissPDF validates the PDF header and encodes the original bytes in a browser worker.
Use raw Base64 for APIs and storage, or include the data URL prefix for browser embedding.
Copy the complete value to the clipboard or save it as a UTF-8 TXT file.
Practical guide
Convert a PDF to standard Base64 text entirely in your browser. KissPDF validates the PDF signature, encodes the original file bytes, and provides both raw Base64 and data URL output without uploading or rewriting the document.
Raw Base64 contains only the encoded characters and optional equals-sign padding expected by most APIs and data stores. A PDF data URL—also called a data URI—contains the same value prefixed with data:application/pdf;base64, so browser code can identify its media type.
Use raw Base64 as a string value in an API, JSON payload, SOAP request, or text-oriented database field. For browser embedding, use the complete PDF data URL as the src of an HTML iframe or embed element, or as the data value of an object element.
A PDF file contains binary bytes. Base64 converts those bytes into a reversible text string; it does not turn the PDF into a different document. In browser code, the selected PDF File is already a kind of Blob. A PDF data URL combines the Base64 string with the application/pdf media-type prefix.
This tool does not parse pages, render fonts, compress images, or create a new PDF. Base64 is a reversible representation of the existing bytes, so decoding the result returns the source file byte for byte.
Every three source bytes become four Base64 characters. The encoder works off the main UI thread, and the visible preview is capped so a long text value does not overwhelm the page. Copying or downloading still uses the complete result.
Clear answers based on how this tool actually works.
Choose a PDF and wait for local encoding. Select raw Base64 or Data URL, then copy the complete result or download it as a TXT file.
Yes. Base64 is a reversible representation of the source bytes. Decoding the result produces the same PDF bytes; the document is not rendered or rewritten.
Raw Base64 contains only the encoded value. A PDF data URL adds data:application/pdf;base64, before that value so software can identify the media type.
Yes. Choose Data URL and use the complete value as the iframe src. The same data URL can be used with an embed src or an object data attribute, although large inline PDFs may be limited by browser memory or Content Security Policy.
No. A PDF contains binary bytes, while Base64 is a text representation of those bytes. In browser code, a selected PDF File is already a kind of Blob; this tool converts its bytes to text.
No. A PDF data URL contains the complete encoded document inside the value. It is not an uploaded file, hosted address, or public sharing link.
No. This page performs PDF-to-Base64 encoding. Converting a Base64 string back into a PDF is the reverse operation and requires a Base64-to-PDF decoder.
No. Standard Base64 is normally about one-third larger than the binary source because three input bytes are represented by four text characters.
No. Anyone with the Base64 value can decode it. Use PDF password protection or an appropriate encryption system when confidentiality is required.
Yes. Encoding copies the existing bytes and does not require the document password. The decoded PDF remains password protected in the same way as the source.
Small results are shown completely. Large results are shortened in the visible preview for performance, while Copy and Download TXT still use the complete value.
No. The file is validated and encoded locally in browser memory. It is not sent to a document-processing server.
Yes. Choose raw Base64 and use the copied value as a JSON string, subject to the size limits of the API or database receiving it.
The current limit is 100 MB on desktop browsers and 32 MB on mobile devices. Base64 output is about one-third larger than the source PDF, so very large results also require additional browser memory.