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Base64 Encoder / Decoder Online Free — PrivaTools

TL;DR: Encode text or files to Base64, or decode Base64 back to the original — runs locally, no upload.

Encode and decode Base64 online for free — convert text, files, or binary data to and from Base64 format instantly. Works entirely in your browser, no data sent anywhere.

Like the rest of the 179-tool PrivaTools suite, Base64 Encoder / Decoder is MIT-licensed and self-hostable. The public demo deletes your file as soon as the response leaves the server — verifiable in the open-source codebase on GitHub.

How to Use Base64 Encoder / Decoder

  1. Choose encode or decode mode — Select whether you want to encode data to Base64 or decode a Base64 string back to its original form.
  2. Enter input — Paste text into the editor, or upload a file (image, PDF, binary — up to 500 MB). For decoding, paste the Base64 string.
  3. Get the result — The output appears instantly. Copy the Base64 string to your clipboard, or download the decoded file.

Frequently Asked Questions

Can I encode files (not just text)?

Yes. Upload any file — images, PDFs, binaries — and the tool returns the Base64-encoded string. Useful for embedding files in JSON, HTML, or CSS.

Is there a size limit for encoding?

Files up to 500 MB can be encoded. Keep in mind that Base64 output is approximately 33% larger than the original file.

What character set is used?

Standard Base64 (RFC 4648) using A-Z, a-z, 0-9, +, and /. URL-safe Base64 (replacing + and / with - and _) is also available.

Last reviewed 2026-01-22 by the PrivaTools maintainers. Source code on (MIT-licensed, self-hostable).

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