URL Encoder/Decoder

Encode text for URLs or decode percent-encoded strings back to plain text.

Encode Decode

Input

Output

Frequently Asked Questions

What is URL Encoder Decoder?

A URL encoder decoder is a free online tool that converts text to URL-safe percent encoding and decodes percent-encoded strings back to plain text.

How do I use this URL Encoder Decoder?

Select Encode or Decode mode, type or paste your text in the input area, and the result appears instantly in the output area.

Is this URL Encoder Decoder free?

Yes, this tool is completely free to use with no signup required.

Percent-encoding method and component boundaries

URL encoding replaces characters that are not safe in a specific URL component with percent-encoded UTF-8 bytes. The correct operation depends on whether the input is an entire URL, one path segment, a query key, or a query value. This tool is designed for component values and does not claim that repeatedly encoding a complete URL will preserve its structure.

Methodology

Encode mode follows encodeURIComponent-style behavior for a component value.
Unicode text is represented as UTF-8 before percent escapes are formed.
Decode mode reverses valid percent escapes and reports malformed sequences rather than guessing.
Reserved delimiters such as slash, question mark, ampersand, and equals have structural meaning and should be handled according to their location.

Worked review example

A query value “red shoes & socks” can be encoded before insertion into a URL so the ampersand is not mistaken for a second parameter. Encoding the complete string “https://example.com/search?q=red shoes” as one component would also encode its colon and slashes, producing a value rather than a navigable URL. Build the URL from separately encoded values or use URLSearchParams in application code.

Test coverage and expected behavior

Test coverage includes spaces, plus signs, ampersands, slashes, percent signs, CJK text, emoji, already encoded values, and malformed percent sequences. We compared representative output with browser URL APIs. The page distinguishes percent encoding from HTML escaping and Base64.

Decision checklist before using the output

First separate the URL into semantic parts. Keep the scheme and host intact, split path segments at their intended slashes, and encode each dynamic query key or value independently. In application code, prefer URL and URLSearchParams so delimiters are assembled by an API rather than string concatenation. Test values containing spaces, plus, ampersand, equals, percent, slash, non-Latin characters, and emoji because these expose most boundary mistakes. Compare the decoded value at the receiver, not only the appearance of the outgoing URL. Avoid encoding a value twice: if input may already contain percent escapes, establish whether it is raw or encoded at the interface boundary. The tool can explain and debug component encoding, but it cannot determine whether a destination is legitimate, prevent open redirects, or replace output encoding appropriate to HTML, JavaScript, SQL, or shell contexts.

Important limitations

application/x-www-form-urlencoded commonly represents spaces as plus signs, unlike generic percent encoding.
Double encoding changes existing percent signs and is a frequent integration bug.
Internationalized host names use a separate domain-name conversion process.
Successful decoding does not make an untrusted URL safe to open.

Sources and specifications

These references define the relevant format or browser behavior. They do not endorse WordCaseFix.

Last reviewed: August 6, 2026