Boring Tools

Base64 Encode/Decode

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Encode text to Base64 or decode Base64 back to text.

Turn text into Base64, or turn Base64 back into text. Base64 is a way of writing arbitrary data using only letters, digits, +, / and =, which makes it safe to embed in JSON, HTML, emails, and URLs-in-disguise such as data URIs.

How it works

Encoding first converts your text to UTF-8 bytes, then writes those bytes in Base64. This means accented letters, emoji, and non-Latin scripts encode correctly and round-trip back to exactly what you typed.

Decoding does the reverse: it reads the Base64, turns it into bytes, and interprets those bytes as UTF-8 text.

How to use it

  1. Choose Encode or Decode with the toggle at the top.
  2. Paste or type into the box below it — it is labelled Text when encoding and Base64 when decoding.
  3. Click the Encode or Decode button (its name follows the mode).
  4. Copy or download the result, or read the red message if the input was not valid.

Options & controls

Mode

Encode / Decode
Switches the direction. Changing mode clears the current result and any error but keeps what you typed in the input, so you can flip a result straight back by pasting it in.

Input and actions

Text / Base64 box
The input. Its label changes with the mode. The tool only runs when you click the action button; it does not update as you type.
Encode / Decode button
Runs the conversion. With an empty input it simply clears the result.
Reset
In the title row. Returns to Encode mode and clears the input, result, and any error.

Result

Result box
Read-only output, shown once a conversion succeeds.
Copy
Copies the full result to the clipboard.
Download
Saves the result as base64-result.txt.
Error message
Shown when decoding text that is not valid Base64 ("That doesn't look like valid Base64."), or in the rare case that encoding fails.

Tips & guidelines

  • Base64 is an encoding, not encryption. Anyone can decode it, so never use it to hide passwords or secrets.
  • Encoded output is about a third longer than the original text.
  • If a decode fails, check for characters that are not part of standard Base64, such as stray quotes or a data: URI prefix — remove everything before the actual Base64 characters first.
  • Line breaks and spaces inside the Base64 you paste are ignored when decoding, so wrapped Base64 (for example from an email or PEM file body) works.

Limits

  • Only the standard alphabet (A–Z a–z 0–9 + /) is understood. URL-safe Base64, which uses - and _, will be reported as invalid — swap those characters for + and / first.
  • Decoded bytes are always read as UTF-8 text. If the Base64 actually holds a binary file such as an image or PDF, the output will be garbled characters; this tool is for text, not for files.

Saved in your browser

Nothing. Your input and results exist only on the page and disappear when you refresh or close it.

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