How to use the Base64 Encode / Decode
- Choose Encode or Decode
- Paste your text or Base64 string
- Copy the result (turn on URL-safe for tokens and URLs)
About this tool
Base64 (RFC 4648) represents bytes using 64 safe characters, so binary data can travel through email, JSON and URLs. It is an encoding, not encryption: anyone can decode it. The browser’s built-in btoa() fails on characters outside Latin-1, such as emoji. This tool converts text to UTF-8 bytes first, so every language works.
URL-safe Base64 (Base64URL) swaps + and / for - and _ and drops the = padding. JWTs use it. The decoder accepts both forms, ignores whitespace, and strips a data:…;base64, prefix.
Frequently asked questions
Is Base64 encryption?
No. Base64 only changes how data is written, and anyone can reverse it. Never use it to hide passwords or secrets.
Why is the Base64 output longer?
Base64 uses 4 characters for every 3 bytes, so it is about 33% larger than the original.
Why does decoding say it is not UTF-8 text?
The Base64 holds binary data, such as an image or a ZIP file, not text. This tool decodes text only.
What is Base64URL?
A variant that uses - and _ instead of + and / and usually drops the = padding, so it is safe in URLs and file names.
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