Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to text instantly. Supports full UTF-8, auto-detects mode, and runs entirely in your browser.

Paste any text to encode it as Base64, or paste a Base64 string to decode it back to readable text. The tool auto-detects whether your input looks like Base64 and suggests the right action. Full UTF-8 support means emojis, accented characters, and CJK text all work correctly.

When to Use the Base64 Encoder/Decoder

Use Base64 encoding when embedding binary content in JSON, passing data through URL-safe channels, encoding email attachments, or debugging API payloads that contain Base64 strings.

Tips

  • Use Base64 to embed small images directly in CSS as data URIs — saves an HTTP request.
  • If your decoded output looks garbled, the original text may not have been UTF-8 encoded before Base64 encoding.
  • Base64 strings always have a length divisible by 4. If not, they may be truncated.
  • For URL-safe Base64, replace + with - and / with _ after encoding.

Frequently Asked Questions

What is Base64 encoding? ▾

Base64 converts binary data into a set of 64 ASCII characters (A-Z, a-z, 0-9, +, /). It is commonly used to embed images in HTML/CSS, send binary data in JSON, and encode email attachments.

Does Base64 encrypt my data? ▾

No. Base64 is an encoding, not encryption. Anyone can decode it. Never use Base64 to hide passwords or sensitive data — it provides zero security.

Why is the Base64 output longer than the input? ▾

Base64 increases size by approximately 33% because it represents every 3 bytes of input as 4 ASCII characters. This is the trade-off for safe ASCII transport.

Does it handle Unicode and emojis? ▾

Yes. We encode the text as UTF-8 before Base64 encoding, so characters from any language and emojis are preserved correctly on decode.

Is my data sent to a server? ▾

No. All encoding and decoding happens in your browser using the built-in btoa/atob functions with a UTF-8 wrapper. Nothing is transmitted.

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