Universal Encoder Decoder is a set of free online tools for encoding, decoding and hashing text, with guides that explain how those encodings behave in URLs, HTML, tokens and files. It is built for developers, SEO specialists and anyone who needs to read or fix an encoded string quickly.
What you can do here
The main tool on the home page offers 15 operations in one place:
- Base64 encode and decode
- URL encode and decode
- HTML encode and decode
- String to hex and hex to string
- Text to binary and binary to text
- MD5, SHA-1, SHA-256 and SHA-512 hashes
- ROT13
Six focused tools handle jobs that need more than a single conversion:
- JWT decoder
- URL parser and query string decoder
- Punycode converter
- Unicode escape and unescape
- JSON escape and unescape
- Image to Base64 and back
Guides explain the problems these tools help solve, such as %20 vs + in URLs, double URL encoding and UTM parameter mistakes.
How the tools process your input
The six focused tools run entirely in your browser: what you paste or upload stays on your device. The main tool on the home page sends your input to the site's server, which computes the result and returns it to your browser. The privacy policy describes this in more detail.
How we check what we publish
- Technical statements in our guides are checked against primary sources: IETF RFCs, the WHATWG URL and HTML standards, MDN Web Docs, Google Search Central and the official Google Sheets and Microsoft Excel documentation. Each guide lists its sources.
- Code examples and sample outputs were produced by running the code, not written from memory.
- We do not publish statistics we cannot source or measure. Where a guide reports a measurement, it says how it was made.
If you find an error, please tell us. Corrections are welcome.
Who runs the site
The site is run by the team behind Universal Encoder Decoder. You can reach us at contact@universal-encoder-decoder.com or through the contact page.