What is URL Encoding?
URL Encoding, also called Percent-Encoding, converts characters that aren't allowed in a URL into a safe format — replacing them with a % followed by their two-digit hexadecimal value. This is essential for passing data like spaces, emojis, JSON, or special symbols through web addresses without breaking them.
encodeURIComponent vs encodeURI
encodeURIComponent encodes everything except A-Z a-z 0-9 - _ . ! ~ * ' ( ). Use it for query param values. encodeURI preserves URL-structural characters like : / ? # & = @. Use it for full URLs.
Why URLs break without encoding
A space in a URL breaks the request. An unencoded & inside a query value is read as a parameter separator. Characters like #, +, and = all carry special meaning in URLs and must be percent-encoded when used as raw data.
Common Codes
%20 = Space %2B = + %3D = = %26 = & %3F = ? %2F = / %23 = # %40 = @
100% Private — No Server Calls
All encoding and decoding happens locally in your browser using native JavaScript. Nothing you paste is ever sent to our servers. Safe for API keys, OAuth tokens, and sensitive query strings.
Encoding vs Encryption
Encoding reformats data for system compatibility — it is not a security measure. Any decoder can instantly reverse percent-encoding. Never rely on URL encoding to protect sensitive data. Use HTTPS and proper auth for security.
When to use Batch mode
Batch mode is ideal when you have multiple redirect URIs, webhook URLs, or API endpoints to encode at once. Process up to 20 URLs in one pass and copy all results to clipboard instantly.