100% Client-Side

URL Encoder

Free online URL encoder. Percent-encode URLs and query string parameters for use in web requests. Encode special characters instantly. — runs 100% in your browser, client-side only. No data is sent to any server. Free to use, no account required.

Free Client-Side No Login No Storage
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URL Decoder Decode percent-encoded URLs back to readable query strings Base64 Encoder Encode text or binary data to Base64 — standard and URL-safe variants HTML Entity Encoder Escape HTML special characters to prevent XSS and display issues

How to Use the URL Encoder

  1. Paste a URL or query string into the input.
  2. The percent-encoded output appears instantly.
  3. Use Component mode (encodeURIComponent) for encoding parameter values, or Full URL mode (encodeURI) to preserve URL structure and only encode unsafe characters.

What is URL encoding?

URL encoding (percent encoding) replaces unsafe ASCII characters with a % followed by two hexadecimal digits. For example, a space becomes %20, and & becomes %26.

Common uses

  • Query parameters — encode values before appending to URLs
  • Form submission — browsers encode form data before sending
  • API requests — encode special characters in API query strings

What is URL Encoding?

URL encoding (also called percent-encoding) converts characters that are not allowed in URLs into a safe format using a % followed by two hex digits. For example, a space becomes %20, & becomes %26. This is required by RFC 3986 for any character outside the unreserved set (A–Z, a–z, 0–9, -, _, ., ~).

Why Use This Tool

URLs have reserved characters with special meanings (?, &, =, #). If your data contains these characters, they must be encoded to prevent them from being interpreted as URL syntax rather than data.

When to Use It

Use URL encoding when building query strings programmatically, passing user input as URL parameters, encoding form data for GET requests, or constructing OAuth redirect URLs with dynamic values.

Who Should Use It

Frontend developers, backend API engineers, auth/OAuth implementers, and growth teams building tracked campaign URLs.

How to Use the URL Encoder

  1. Paste only the parameter value (not the full URL).
  2. Run encoding and copy the %XX-safe output.
  3. Append encoded value to query strings or redirect parameters.
  4. Decode once on the server/application side before using the value.

Security note

Encoding prevents URL parsing issues but does not sanitize malicious input. Combine with strict validation and output escaping.

Common Uses

  • Encoding query string parameters before appending to URLs
  • Safely passing special characters like &, =, +, #, ? in URL parameters
  • Encoding form data submitted via GET requests
  • Building API request URLs programmatically

Frequently Asked Questions

What is the difference between URL encoding and Base64 encoding?

URL encoding makes text safe to include in URLs using % notation. Base64 encoding converts binary data to ASCII text. They serve different purposes — URL encoding is for URLs, Base64 is for data transmission.

Why does + sometimes mean a space in URLs?

In the application/x-www-form-urlencoded format (HTML forms), + represents a space. In strict RFC 3986 URL encoding, a space is %20. This is why URL-safe Base64 uses - instead of + — to avoid this ambiguity.

Should I encode the entire URL or just the parameters?

Only encode the parameter values (and keys), not the entire URL. Encoding the full URL would also encode the /, ?, and & characters that give the URL its structure.