← utilities

Base64 Encoder

Encode and decode in this tab. UTF-8 safe. Nothing uploaded.

Mode
Alphabet
Status

Paste or type to encode. Toggle Decode for Base64 → text.

Local file
Optional. Stays in this tab.

100% Client-Side Processing

What Base64 Encoder is

Encode turns text or file bytes into Base64. Decode turns Base64 back into text or downloadable bytes. You stay in this tab. There is no paste bin and no upload folder.

Standard alphabet uses + and /. URL-safe swaps those for - and _. Padding is optional on decode, so a token from a query string can still parse. Text uses UTF-8 through TextEncoder and TextDecoder. You can also choose a local file, run the same path, and download the resulting bytes. Invalid Base64 shows in the status line. You do not get a silent empty box.

How to use it

  1. Pick Encode or Decode, then Standard or URL-safe.
  2. Paste text, or choose a file that should stay in this tab.
  3. Run Encode or Decode. Watch the status line if the input is bad.
  4. Copy the text, or download the bytes if you started from a file.

Common uses

Turn a short string into a data URL fragment. Read a token that arrived in a mail. Check a JWT-looking blob that is only Base64, not a full JWT tool. Convert a small SVG or JSON snippet for an inline attribute. Recover a file a teammate sent as a long line. Inspect a cookie value that looks like alphabet soup. Prepare a URL-safe payload for a query without inventing your own table.

Developers use it when a log shows only the encoded form. Designers use it when a tiny asset must sit in CSS. Support staff use it when a customer pasted a garbled attachment as text. Students use it to see that Base64 is an alphabet, not a cipher. If you need a checksum instead, that is a different page. If you need pretty JSON after a decode, paste the text into the formatter.

File mode is for small local blobs you already have. A huge video will strain the tab. Prefer a desktop tool for gigabyte archives. After decode, open the download and confirm the name and type. The page cannot guess a file extension from random bytes. You name the save. Text mode is enough for most tokens and snippets.

Privacy

We do not receive the text or the file. Refreshing the page clears source and output. Close the tab when you are done with a private payload.