ToolAtlas
FavoritesRecent

Base64 encode and decode

Processed in this browser

Text limit: 4000000 characters

File limit: 8 MB

This tool never uploads your input.

Flip UTF-8 text to Base64 or back in this tab, including a URL-safe alphabet. Base64 is encoding, not encryption — anyone can decode it. Binary files and data-URI images belong on the sibling tools.

You have a token, a PEM fragment, or a config value that is Base64 and you want the UTF-8 back — or the other way. That is this page. People say “Base64 encrypt”; they mean encode.

File Base64 owns arbitrary files. Image to Base64 owns data:image/... URIs. JWT decoder owns three-segment tokens (still not encryption).

Encode vs decode

  1. Paste text. Pick standard or URL-safe.
  2. Encode or decode in this tab.
  3. If decode looks like garbage, you had the wrong alphabet, or the source was binary — use the file tool.

UTF-8 is the text assumption. Legacy encodings will mojibake.

Honest limits

  • Not a secret keeper. Encoded credentials are still credentials.
  • Huge pastes are limited by the tab, not a cloud queue.
  • We do not implement raw MIME headers for you.

For hashing the decoded string, use hash generator after you have the plaintext.

FAQ

Is Base64 encryption?

No. It is a reversible alphabet so binary can travel in text. If you needed a password-based cipher, that is AES encrypt — and even that is not a product you should invent for real secrets without a threat model.

Why do I see %3D or dashes instead of plus signs?

URL-safe Base64 swaps +// and often skips padding. Decode with the matching alphabet or the string will fail.

Can I encode a PDF or photo here?

Use file Base64 for arbitrary files, or image to Base64 for a data URI. This page is the text job.

Does decode prove the payload is safe?

No. Decoding only reverses the alphabet. It is not an antivirus.

Is this how email attachments work?

MIME uses Base64 and that is why a 20 MB file can trip Gmail’s 25 MB send cap. You do not need this tool to attach a file in Gmail.

Is the paste uploaded?

No. Conversion stays in this tab.

Related tools