Base64 Encoder & Decoder
Encode UTF-8 text to Base64 or decode Base64 strings back to plain text. Useful for API payloads, Basic Auth debugging, and data snippets.
What is this tool?
This Base64 encoder and decoder converts between UTF-8 text and the standard Base64 alphabet. Base64 represents binary-safe bytes using ASCII characters, which is why it appears in HTTP headers, JSON payloads, email bodies, certificates, and data URI workflows.
The important technical detail is that Base64 is an encoding, not encryption. It does not require a secret key, and anyone can reverse it. The output is also larger than the original data because every three bytes become four Base64 characters, with = padding used when the byte length is not divisible by three.
Use this tool when you need to inspect or prepare text-based Base64 values quickly. It is not a file encoder, a URL-safe Base64 normalizer, or a cryptographic protection layer.
How to use
- Open Encode to convert readable UTF-8 text into Base64, or Decode to convert Base64 back to text.
- Paste the input exactly as it appears. Base64 padding such as
=is meaningful for strict decoders. - Run the conversion and copy the output.
- If decoding fails, check for missing padding, pasted whitespace, or characters outside the standard Base64 alphabet.
Examples
| Input / setting | Output | Notes |
|---|---|---|
Hello | SGVsbG8= | UTF-8 text encoded with standard Base64. |
SGVsbG8= | Hello | The same value decoded back to text. |
user:pass | dXNlcjpwYXNz | The text form used before building a Basic Auth header. |
Related tools & concepts
Last reviewed: 2026-05-08