Base64 Decoder
Decode Base64 or Base64URL to text, or to a file if it's an image or PDF. Handles missing padding and line breaks. No uploads.
Runs in your browser. Nothing you enter is uploaded
About Base64 Decoder
Paste Base64 to see what it contains. Text is shown as UTF-8, so accents and emoji come through intact. If the data is a file, such as a PNG image or a PDF, it's recognised and you can preview or download it.
Both standard Base64 and the URL-safe variant used in JWTs and web addresses are accepted, with or without = padding, line breaks or a data: prefix. Everything is decoded in your browser.
Convert text or any file to Base64, the encoding used for email attachments, data URIs, basic authentication headers and JSON payloads, or decode Base64 back to readable text or the original file.
Text is encoded as UTF-8, so every language and emoji works, and the URL-safe variant (Base64URL) is one switch away. Encoding and decoding happen in your browser, so passwords, tokens and files stay on your device.
How to use Base64 Decoder
- 1Choose Encode or Decode.
- 2Type or paste text, or pick a file.
- 3Copy the result, or download it as a file.
Frequently asked questions
Is my data uploaded?
No. Base64 conversion runs in your browser, so nothing you paste or open leaves your device.
Is Base64 encryption?
No. Base64 only changes how data is written, and anyone can decode it. Don't use it to hide passwords or secrets.
What's URL-safe Base64?
A variant that uses - and _ instead of + and /, usually without = padding, so it can go in web addresses and file names. JWTs use it. The decoder accepts both.
Why is the Base64 bigger than my file?
Base64 uses 4 characters for every 3 bytes, so it's about 33% larger than the original. That's normal.