Base64 Encoder & Decoder
Convert text or files to and from Base64, with full UTF-8 handling and a Base64URL option for tokens and query strings. You can swap input and output, download decoded files, and read clear validation messages along the way. Worth remembering: Base64 is encoding, not encryption — and none of it leaves your device.
- 100% free
- Private & safe
- Runs in your browser
Why use Base64 Encoder and Decoder?
Base64 Encoder and Decoder is a quick, no-nonsense developer utility that runs entirely client-side, so your code and data never leave your machine.
- Runs instantly in your browser — nothing to install, nothing uploaded.
- Completely free, with no account, no watermarks and no usage limits.
- Handles Standard Base64; Base64URL (URL-safe).
- Choose Text mode or File mode.
- Works on any device — desktop, tablet and phone — and is fully keyboard accessible.
How to use Base64 Encoder and Decoder
- Choose Text mode or File mode.
- In Text mode, type or paste and toggle between encode and decode; use Base64URL if you need URL-safe output.
- In File mode, select a file to encode, or paste Base64 to decode and download the original file.
- Swap input and output, copy the result, and read validation messages if the input is malformed.
Examples
- Encoding a small logo as a Base64 data string.
- Decoding a Base64 token payload to read its text.
Supported formats & limits
- Standard Base64
- Base64URL (URL-safe)
Limitations
- Base64 increases size by roughly a third; it is not compression.
- Very large files are limited by browser memory.
- Decoded HTML is shown as text and never rendered as live HTML for safety.
Frequently asked questions
Is Base64 secure or encrypted?
No. Base64 is a reversible encoding, not encryption. Anyone can decode it, so never use it to protect secrets.
What is Base64URL?
A URL-safe variant that replaces + and / with - and _ so the output is safe in URLs and filenames.
Can I encode files, not just text?
Yes. Switch to File mode to encode a file to Base64, or decode Base64 back into a downloadable file.