Universal Decoder

Decode/encode strings in Base64, URL and hexadecimal, with multi-layer auto-decode.

Cryptography
Development
Free

BASE64 Converter

Input (Plain or encoded text)

Result

About

Universal Decoder

Instantly encode and decode a string in Base64, URL encoding (percent-encoding) or hexadecimal. Auto-Decode mode detects the format and automatically unwraps successive layers, handy for CTFs, obfuscated payload analysis and API debugging. Everything happens in your browser.

What it does

Base64 (standard and URL-safe), URL encoding and hexadecimal
Encoding and decoding both ways
Auto-Decode: format detection and unwrapping of up to 5 nested layers
UTF-8 support (accents, emojis)
One-click copy of the result

Frequently asked questions

Which encoding formats are supported?

Three formats: Base64 (standard and URL-safe variant), URL encoding (percent-encoding) and hexadecimal. Each can be encoded or decoded from its tab.

How does Auto-Decode work?

The tool tries Base64, URL encoding and hexadecimal in turn, applies the decoding that works, then starts again on the result, up to 5 times or until nothing changes. A message tells you whether a decoding was applied.

Can I use this tool for CTF challenges?

Yes, especially for strings encoded several times (Base64 inside URL encoding, hex of a Base64…). For JWTs, ROT13 or hashes, use a dedicated tool: they are not supported here.

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BASE64 Converter Clear

BASE64 Converter