URL Encode Online

What Is URL Encoding?

URL encoding (also called percent-encoding) is a mechanism for encoding information in a Uniform Resource Identifier (URI) so that only characters allowed by RFC 3986 appear in the final string. Any character that is not an unreserved character (A–Z, a–z, 0–9, -, _, ., ~) is replaced by a percent sign followed by two hexadecimal digits representing the character's UTF-8 byte value — for example, a space becomes %20 and & becomes %26.

Percent-encoding is required because URLs can only contain a limited set of ASCII characters. When a URL includes characters outside this set — spaces, Unicode letters, symbols like &, =, or / used as literal values rather than structural delimiters — those characters must be encoded to prevent the URL parser from misinterpreting them. This is especially critical for query string values, where unencoded & or = would break the parameter structure.

Why Use This Tool?

Instantly see how your text encodes under both modes, with a live side-by-side comparison — no need to write code to check edge cases.

How to Use This URL Encoder Online

No account, no installation. Paste or type your text into the input field and the percent-encoded result appears instantly. Everything runs in your browser — your data never leaves your device.

1. 1
   Paste Your Text or URL

   Enter any string — a query parameter value, a full URL, a path segment, or a JSON payload. The encoder processes it character by character according to RFC 3986.
2. 2
   Choose the Encoding Mode

   Select encodeURIComponent to encode individual parameter values (encodes everything except unreserved characters). Select encodeURI to encode a full URL while preserving its structural characters like ://?#&=.
3. 3
   Copy the Encoded Output

   The percent-encoded string appears instantly. Click Copy to grab the result and paste it directly into your API call, form action, or config file.
4. 4
   Decode It Back if Needed

   Made a mistake or want to verify the result? Switch to the URL Decoder tool with one click to reverse the encoding.

Which Characters Get Encoded?

RFC 3986 divides URL characters into two categories: unreserved characters (never encoded) and reserved characters (have special meaning — encoded or preserved depending on context). The table below shows how the two JavaScript functions treat key characters:

encodeURIComponent vs encodeURI

JavaScript provides two encoding functions with very different behavior. Choosing the wrong one is one of the most common URL-handling bugs:

Common Use Cases

Code Examples

How to URL-encode strings in popular languages and environments:

// Encode a query parameter value (most common case)
encodeURIComponent('hello world & more') // → "hello%20world%20%26%20more"

// Encode a complete URL (preserves ://?#& structure)
encodeURI('https://example.com/path?q=hello world') // → "https://example.com/path?q=hello%20world"

// Build a query string safely
const params = new URLSearchParams({ q: 'hello world', lang: 'en' })
const url = `https://example.com/search?${params}` // uses + for spaces

from urllib.parse import quote, urlencode, quote_plus

# Encode a path segment or query value
quote('hello world & more')          # → 'hello%20world%20%26%20more'

# Encode for application/x-www-form-urlencoded (space → +)
quote_plus('hello world')            # → 'hello+world'

# Build a query string
urlencode({'q': 'hello world', 'lang': 'en'})  # → 'q=hello+world&lang=en'

const url = new URL('https://example.com/search')
url.searchParams.set('q', 'hello world & more')
url.searchParams.set('lang', 'en')
console.log(url.toString())
// → https://example.com/search?q=hello+world+%26+more&lang=en

# curl automatically percent-encodes --data fields
curl -G "https://example.com/search" --data-urlencode "q=hello world & more"

# Manual encoding with Python one-liner
python3 -c "from urllib.parse import quote; print(quote('hello world'))"

URL Encoder vs. Alternatives

Several tools can percent-encode text, but they differ in control, privacy, and context.

Frequently Asked Questions