Ever tried to put a space or a special symbol in a URL and had it break? Our free Online URL Encoder & Decoder solves that problem instantly. It converts any string into a safe, valid URL format (percent-encoding) and can decode it back just as easily, ensuring your links and data work perfectly every time.

How to Use the URL Encoder & Decoder

Our tool provides instant, one-click conversions:

1. Enter Your Data: Paste any string or full URL into the "Input" box.
2. Choose an Action: Click Encode to convert to a URL-safe format, or click Decode to convert it back to human-readable text.
3. Copy the Result: The converted text will appear in the "Output" box, ready to use.

Example: Encoding URL Parameters

When passing data in a URL, special characters like `&` and spaces must be encoded.

Before (Human-Readable String):

/search?q=cats & dogs

After (Encoded for URL):

%2Fsearch%3Fq%3Dcats%20%26%20dogs

What is URL Encoding (Percent-Encoding)?

URL encoding, also known as percent-encoding, is a mechanism for converting characters in a Uniform Resource Identifier (URI) into a format that is universally accepted by web servers and browsers. The URI specification (RFC 3986) reserves certain characters for special use (e.g., ?, &, /) and restricts the character set to a small subset of ASCII.

To include data that contains these reserved characters or non-ASCII characters, they must be encoded. This process replaces the unsafe character with a % symbol followed by its two-digit hexadecimal representation.

URL encoding is crucial for:

• Passing Data in Query Strings: Ensuring that values in `?key=value` pairs are transmitted correctly without being misinterpreted as part of the URL structure.
• Creating Valid URLs: Allowing filenames or search queries with spaces and special symbols to be part of a valid link.
• Maintaining Data Integrity: Making sure the data sent from a browser arrives at the server exactly as intended.

Frequently Asked Questions (FAQ)

Q1: What's the difference between `encodeURI` and `encodeURIComponent`?

This tool uses `encodeURIComponent`. This function is more aggressive and encodes a larger set of characters, including those with special meaning in a URL like : / ? & =. It's designed to encode a single piece of data. In contrast, `encodeURI` is meant for encoding a full URL and will not encode those reserved characters, assuming they are part of the URL's structure.

Q2: Why do I get an "Invalid URI sequence" error when decoding?

This error typically happens when the input string contains a % symbol that is not followed by two valid hexadecimal characters (0-9, a-f). For example, a lone percent sign (`%`) or a malformed sequence like `%2` will cause the decoder to fail, as it's not a valid percent-encoded sequence.

Q3: Is this tool safe to use with sensitive information?

Yes. This is a fully client-side tool. All encoding and decoding happens directly in your web browser using JavaScript. No data is ever sent to our servers or any third party, ensuring your information remains completely private and secure.