Base64 → PDF

Decode a Base64 string into a PDF file

APIs and database columns frequently return PDFs as Base64 text, because it survives JSON transport safely. That leaves you holding a wall of characters when what you need is the document. This decodes the string back into a real PDF you can open and save.

How to use it

  1. Paste the Base64 string. A data:application/pdf prefix is handled for you.
  2. Decode to reconstruct the binary PDF.
  3. Check that the file is recognised and the size looks plausible.
  4. Download the PDF and open it.

Frequently asked questions

The download opens as a broken file. Why?

Almost always a truncated string. Base64 PDFs are long and copying from a terminal or a log viewer often clips the end. Confirm the string finishes cleanly, with padding equals signs if present, and that no line breaks were introduced mid-copy.

Is the document sent to a server?

No, which is the main reason to use a local tool for this. Base64 PDFs are commonly invoices, contracts and statements. The decode happens in your browser and the file never leaves your device.

Is there a size limit?

Practically, your browser memory. A Base64 string is a third larger than the file it represents, so very large documents can be slow to paste and decode.

How can I tell whether a string really is a PDF?

Base64-encoded PDFs almost always begin with JVBERi0, which is what the PDF header bytes encode to. If your string starts with something else it is probably a different file type, and the Base64 to Image tool may be the one you want.