- 1Choose file
- 2Adjust
- 3Download
Base64 Encoder & Decoder online, free
Encode text and files to Base64 or Data URLs, or decode Base64 strings to UTF-8 plaintext with Base64URL mode support.
- Runs in your browser — no upload
- Free, no sign-up, no watermark
How to use Base64 Encoder & Decoder · Base64 Encoder & Decoder — frequently asked questions
How to use Base64 Encoder & Decoder
- 1
Add your file
Drop a file on the page, paste it, or click Select Files. Nothing is uploaded — it opens straight in your browser.
- 2
Fine-tune the settings
Set operation mode in the Fine-tune panel, or keep the defaults — they suit most files.
- 3
Run Base64 Encoder & Decoder
Press the start button. Processing happens on your device, usually in seconds.
- 4
Download the result
Save the finished file, or continue with another tool without downloading in between.
What Base64 Encoder & Decoder can do
- Operation Mode: encode and decode
- Private by design — files are processed in your browser and never uploaded
- Free with no sign-up, no watermark and no daily limit
Common tasks
Base64 Encoder & Decoder — frequently asked questions
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format using 64 printable characters (A–Z, a–z, 0–9, +, and /).
What is Base64URL and when should I use it?
Base64URL replaces `+` with `-` and `/` with `_`, and omits trailing `=` padding characters. It is safe for use in URL query parameters, filenames, and JSON Web Tokens (JWTs).
Can I encode binary files?
Yes. You can encode UTF-8 text strings or upload binary files (such as images, icons, and audio) to convert them into standard Base64 or Data URLs.
How does decoding handle invalid characters?
The decoder sanitizes whitespace and validates padding, decoding clean UTF-8 plaintext and notifying you if malformed characters are encountered.
Is my data kept private?
Yes. All Base64 encoding and decoding executes 100% client-side in your web browser with zero server uploads.
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