Encode query strings for safe URLs. Decode percent-encoded text back to readable form. Auto-detects whether your input is already encoded —one button does the right thing.
encodeURIComponent encodes all special characters —including / ? & = #. Use this for encoding individual query parameter values. encodeURI preserves URL structure characters —use it for encoding a full URL string, not component values.
Common mistake: using encodeURI on query values. It won't encode & or =, which breaks query string parsing. Always use encodeURIComponent for query parameter values. The "Auto Detect" button checks whether input contains %XX patterns indicating pre-encoded text.
See also: Base64 Encode/Decode · HTML Entity Encoder · JWT Decoder