PDF to Base64 Converter

Drop a PDF and get a Base64 string — raw, or as a data:application/pdf URI. Everything runs in your browser — the file is never uploaded.

How to convert a PDF to Base64

Drag any PDF onto the drop zone above (or click to browse). The tool reads it locally with the browser's FileReader API and produces a Base64 string. By default you get the raw Base64 payload — ideal for JSON or a database column. Click Copy to grab it. Use the Data URI toggle to wrap it as data:application/pdf;base64,JVBERi0xLjQK…, which you can drop into an href, iframe, or embed.

Why convert a PDF to Base64?

Base64 turns binary PDF bytes into plain ASCII text, which is exactly what you need anywhere a transport only carries text:

• Embed in JSON API payloads: JSON has no binary type, so a PDF must be Base64-encoded to ride inside a request or response body.
• Store in a DB text column: keep a generated invoice or report alongside its row in a TEXT/VARCHAR column instead of a separate blob store.
• Email / MIME attachments: SMTP and MIME encode attachments as Base64 under the hood — the same encoding you get here.
• Data URIs: the data:application/pdf;base64,… form lets you reference a whole PDF inline, with no separate file to host.

Size warning

Base64 is ~33% bigger than the original binary, because every 3 bytes become 4 ASCII characters. A 5 MB PDF becomes ~6.7 MB of text. That overhead is fine for transport — JSON bodies, email, a quick paste — but it adds up:

• Database limits: watch column size caps (and row/packet limits) before storing large encoded PDFs as text.
• Payload bloat: a Base64 PDF inflates request sizes and memory use; for large or frequently reused files, an upload + URL reference is usually better.

Is this private?

Yes. The conversion happens entirely client-side in JavaScript. Your PDF is read into memory in the browser and encoded locally — it is never sent to a server. That matters for confidential PDFs like contracts, statements, or medical records: nothing leaves your machine. You can confirm it by opening DevTools → Network: adding a PDF fires no upload request.

Frequently asked questions

How do I convert a PDF to Base64?

Drop the PDF onto the converter above. It reads the file locally and outputs raw Base64 by default; toggle Data URI for the data:application/pdf;base64,… form, then click Copy.

Is it safe to convert a PDF to Base64 online?

On base64.dev, yes — everything runs in your browser. The PDF is never uploaded, so confidential documents stay on your machine.

How much bigger is a PDF after Base64 encoding?

About 33% larger. A 5 MB PDF becomes ~6.7 MB of text — fine for transport, but mind database column limits.

What is the data URI for a PDF?

It looks like data:application/pdf;base64,JVBERi0xLjQK… — the application/pdf MIME type, then ;base64,, then the encoded payload. Use it as an href, iframe, or embed source.