Developer tool

Base64 Encoder & Decoder Online

Encode text or files into Base64, or decode a Base64 string into readable text in your browser.

Presets:
Base64 Variant:
Format:
Input Data 0 chars | 0 bytes
// Image / media preview will appear here if input is a valid Base64 image or file data URL...
Input Size 0 B
Output Size 0 B
Size Expansion 0%
Base64 Status -

How to use this tool

  1. Choose Encode or Decode and the input mode for your content.
  2. Enter text, select a file or paste a Base64 value.
  3. Run the conversion and review the output before copying or downloading.

Example and use case

The ASCII text Hello encodes to SGVsbG8=. A JWT uses Base64url, which has different alphabet and padding conventions.

Limitations to check

Base64 is encoding, not encryption, and generally increases data size. Binary bytes are not necessarily valid UTF-8 text. Do not assume standard Base64 and Base64url are interchangeable.

Processing and privacy

The tool's browser code handles entered text or selected files locally. Optional URL imports and external resources can make network requests. This website also uses third-party scripts, including analytics and advertising. Read the privacy policy and use sample data when testing sensitive workflows.

Found a problem? Report a tool issue with the browser version and steps to reproduce it. Avoid sending private document content or credentials.

Frequently asked questions

Is Base64 encrypted?

No. Anyone can decode it. It is a way to represent bytes as text, not a method for protecting secrets.

Why does decoded output look unreadable?

The data may be binary or use a different text encoding. Use the correct output mode and character encoding.

Why is the encoded string larger?

Base64 represents three input bytes using four encoded characters, plus any required padding.

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