URL Encoder / Decoder

Encode or decode URLs, query strings, and form data with UTF‑8 support, selective encoding, and live preview.

Mode: Encode · Charset: UTF‑8 · Client-side only

Quick examples

Reserved characters

Common encodings:

space → %20 or +
? → %3F, & → %26, = → %3D

Developer tips

Use encodeURIComponent() for parameter values and decodeURIComponent() when reading them.

How this URL encoder/decoder works

This tool converts text between normal (human-readable) form and percent-encoded form used in URLs and HTTP requests. It uses the same UTF‑8 encoding rules that modern browsers use.

When you click Encode, characters that are not safe in URLs (such as spaces, quotes, and non‑ASCII characters) are replaced with % followed by two hexadecimal digits. When you click Decode, those sequences are converted back to their original characters.

Encoding rules in a nutshell

For each character c in the input:

  1. If c is a letter (A–Z, a–z), digit (0–9), or one of - _ . ~, leave it as is.
  2. Otherwise, convert c to its UTF‑8 byte sequence.
  3. For each byte b, output % followed by the two‑digit uppercase hex value of b.

Example: ✓ (U+2713) → UTF‑8 bytes E2 9C 93 → %E2%9C%93

encodeURI vs encodeURIComponent

JavaScript provides two related functions:

  • encodeURI() – for a full URL. It does not encode reserved characters like :, /, ?, #.
  • encodeURIComponent() – for individual components (e.g. query parameter values). It encodes almost everything except letters, digits, - _ . ~.

Typical usage:

// Encode a query parameter value
const q = "hello world & coffee";
const url = "https://example.com/search?q=" + encodeURIComponent(q);
// https://example.com/search?q=hello%20world%20%26%20coffee

Common use cases

  • Debugging long or nested URLs from logs or redirects.
  • Encoding query parameters or form data before sending a request.
  • Decoding callback URLs from OAuth, SAML, or other SSO flows.
  • Bulk encoding/decoding lists of URLs (enable “Process each line separately”).

FAQ

What does a URL encoder/decoder do?

A URL encoder converts unsafe characters into a safe representation using percent-encoding (for example, space → %20). A decoder reverses this process and restores the original text.

When should I encode vs. decode?

Encode when you are creating URLs or HTTP requests. Decode when you are reading or debugging existing URLs.

What about the “space as +” option?

In URL query strings and application/x-www-form-urlencoded form data, spaces are often represented as + instead of %20. Turn on “Encode space as +” if you are working with HTML forms or libraries that expect this behavior.

Is my data sent anywhere?

All encoding and decoding is done locally in your browser using JavaScript. The tool does not send your input to a server. Still, avoid using highly sensitive data on shared or untrusted devices.