URL Encode/Decode

What is URL Encoding

URL encoding (also known as percent-encoding) converts special and non-ASCII characters in a URL into %XX format. Since URLs can only contain a limited ASCII character set, any reserved characters or non-Latin text must be encoded before being safely embedded in a URL.

encodeURI vs encodeURIComponent

Common encodings: space → %20, & → %26, = → %3D, + → %2B, # → %23

HTML forms (application/x-www-form-urlencoded) encode spaces as +, while RFC 3986 uses %20 — these are different encodings.

Common Use Cases

• Building API requests: Encode Chinese characters or special symbols in query parameters before appending to a URL
• Handling form submissions: Understand how browsers encode form data into key=value&key2=value2 format
• Debugging redirects: Decode nested-encoded redirect_uri parameters in callback URLs
• Web scraping: Properly encode non-ASCII characters in request paths to avoid 400 errors

How to Use

1. Paste the raw text to encode or a percent-encoded string to decode in the input field
2. Select encode or decode mode — the tool processes your input and displays results in real time
3. Click the copy button to grab the processed string for use in your code or URLs

FAQ

Should spaces be encoded as %20 or +?

It depends on context. URL paths and query parameters should use %20 (RFC 3986); application/x-www-form-urlencoded format (HTML form default) uses +. Prefer %20 for consistency and to avoid ambiguity.

Why do I get garbled text after decoding?

The most common cause is a character encoding mismatch — the text was encoded using GBK/GB2312 but decoded as UTF-8. Verify the source data's character encoding. This tool uses UTF-8 by default.

Should I encode the entire URL or just the parameter values?

Only encode parameter values. Using encodeURIComponent() on an entire URL will encode structural characters like ://, ?, and &, breaking the URL. Use encodeURI() for complete URLs.