URL Encoder / Decoder
Encode special characters into percent-encoded URI strings or decode encoded URLs back to readable text.
URL Encoder & Decoder: Percent-Encoding & RFC 3986 URI Sanitizer
Uniform Resource Identifiers (URIs) adhere to rigid character encoding rules defined by the Internet Engineering Task Force (IETF RFC 3986). When URLs contain spaces, non-ASCII international characters, or reserved punctuation symbols (such as `&`, `?`, `#`, `/`), web servers and browsers can misinterpret query parameters, truncate strings, or reject requests.
ToolQix URL Encoder & Decoder ensures your links and query parameters adhere to standards. Encode special characters into percent-encoded hex sequences (e.g., spaces to `%20` or `+`, `&` to `%26`), or decode encoded strings back into readable text with live bidirectional feedback.
IETF RFC 3986 Specifications: Reserved vs. Unreserved Characters
RFC 3986 categorizes characters into Unreserved (letters `A-Z`, `a-z`, digits `0-9`, and `-`, `_`, `.`, `~`) which never require encoding, and Reserved characters (such as `:`, `/`, `?`, `#`, `[`, `]`, `@`, `!`, `$`, `&`, `'`, `(`, `)`, `*`, `+`, `,`, `;`, `=`) which represent structural URI delimiters. When reserved characters appear inside data values, they must be percent-encoded as `%` followed by their 2-digit hexadecimal ASCII/UTF-8 byte value.
How to Use URL Encoder / Decoder Step-by-Step
Select Operation Mode
Choose 'Encode URL' to sanitize text or 'Decode URL' to convert percent-encoded strings back to text.
Input URL or Query String
Paste your web address, API query string, or text parameter into the input area.
Select Encoding Standard
Choose RFC 3986 (encodes spaces as `%20`) or Form Data (encodes spaces as `+`).
Copy Processed Output
Copy the sanitized, valid URL directly to your clipboard for API integration or web links.
URL Encoder / Decoder Industry Use Cases
API Query Parameter Formatting
Encode search queries, authentication tokens, and filter arguments passed in GET request URLs.
Deep Linking & Webhooks
Pass destination URLs as query parameters inside redirect services without breaking the parent URL structure.
Social Media Share Links
Generate Twitter/X, WhatsApp, and LinkedIn share intent URLs containing pre-written text with line breaks and hashtags.
Internationalized URL (IRI) Encoding
Encode non-Latin characters (Chinese, Arabic, Cyrillic, accented letters) into valid percent-encoded ASCII URLs.
URL Encoder / Decoder Best Practices & Tips
- Use `encodeURIComponent` when encoding individual query parameter values, but use `encodeURI` if you are encoding an entire complete URL (to preserve `https://` and `/`).
- In modern REST APIs, use `%20` for spaces rather than `+`; while `+` is valid in form submissions, `%20` is universally safe under RFC 3986.
- Never encode an already-encoded URL, as this creates double-encoding bugs (e.g., `%20` becomes `%2520`).
- Ensure all UTF-8 multi-byte characters are encoded as multi-byte sequences (e.g., '€' is encoded as `%E2%82%AC`).
Common URL Percent-Encoding Characters & Hex Equivalents
| Character | Standard Name | Percent-Encoded (Hex) | Reserved Meaning in URIs |
|---|---|---|---|
| Space | Whitespace | %20 (or +) | Splits command arguments (must be encoded) |
| & | Ampersand | %26 | Delimits distinct query key-value pairs |
| ? | Question Mark | %3F | Marks the beginning of the query string |
| = | Equals Sign | %3D | Separates query parameter keys from values |
| # | Hash / Octothorpe | %23 | Marks the beginning of an in-page fragment anchor |
| / | Forward Slash | %2F | Delimits hierarchical path segments |
| % | Percent Symbol | %25 | The percent-encoding indicator itself |
FAQs About URL Encoder / Decoder
What is the difference between encodeURI and encodeURIComponent in JavaScript?
`encodeURI` is designed for complete URLs; it does not encode structural characters like `http://`, `:`, `/`, `?`, and `&`. `encodeURIComponent` is designed for individual parameter values; it encodes all reserved characters (including `/` and `&`) so the value doesn't break the parent URL structure.
Why are spaces sometimes encoded as '%20' and sometimes as '+'?
RFC 3986 (the universal URI specification) mandates `%20` for spaces. The `application/x-www-form-urlencoded` standard (used historically by HTML forms in POST/GET submissions) allows spaces to be encoded as `+`. `%20` is universally accepted everywhere.
What is double-encoding?
Double-encoding occurs when an already-encoded URL is encoded a second time. For example, a space is encoded to `%20`, and on the second pass, the `%` is encoded to `%25`, resulting in `%2520`. This causes server lookup failures and 404 errors.
Does this tool support international non-English characters?
Yes. The tool supports full Unicode UTF-8 percent-encoding, properly encoding multi-byte characters like emojis (`🚀` → `%F0%9F%9A%80`) and non-Latin alphabets.
Is any URL data sent across external networks?
No. All URL encoding and decoding runs 100% locally inside your web browser's memory.
Tested Methodology & Client-Side Processing
Reviewed: October 21, 2026Calculations, algorithms, and transformations in this utility run directly in your browser without sending your private inputs to remote processing servers. Formulas reference established technical specifications and official documentation under our Editorial & Testing Policy.