Encoder / Decoder — Base64, URL, Hex, HTML Entities
// encode & decode
Convert between Base64, Base64url, URL encoding, HTML entities and hex — all in your browser. Useful for debugging payloads, sanitising input and inspecting encoded strings.
format
input
0 chars
looks like
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encoded output
format reference
| Base64 | SGVsbG8gV29ybGQ= | RFC 4648. Encodes binary data as ASCII using 64 characters (A–Z, a–z, 0–9, +, /). Standard for email attachments, data URIs and basic HTTP auth. padding |
| Base64url | SGVsbG8gV29ybGQ |
URL-safe variant — replaces + with - and / with _, strips padding.
Used in JWT tokens, OAuth 2.0 PKCE, and anywhere Base64 appears in URLs.
no padding
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| URL Encode | Hello%20World%21 |
Percent-encoding (RFC 3986). Replaces characters unsafe in URLs with %XX hex sequences.
Essential for query strings, form data and HTTP headers.
rfc 3986
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| HTML Entities | <script> |
Escapes characters that have special meaning in HTML — prevents XSS when inserting untrusted data into HTML context.
Encodes < > & " ' and extended characters.
xss prevention
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| Hex | 48656c6c6f | Hexadecimal representation of UTF-8 bytes. Two hex digits per byte. Useful for binary inspection, network payloads and low-level debugging. utf-8 bytes |
| Binary | 01001000 01101001 | Binary (base-2) representation of UTF-8 bytes. Eight bits per byte, space-delimited. Useful for educational purposes and low-level protocol analysis. utf-8 bytes |