URL encoding (percent encoding) converts characters that cannot be used in URLs (non-ASCII characters, special characters, spaces) into safe ASCII format using %XX notation. This allows any character to be safely included in a URL.
encodeURIComponent vs encodeURI Difference
encodeURIComponent (Recommended)
Use for query parameter values. Encodes all special characters (:, /, ?, #, etc.) for safety.
Input: a=1&b=2 → Output: a%3D1%26b%3D2
encodeURI
Use for complete URLs. Preserves URL structure characters (:, /, ?, #) and only encodes non-ASCII characters.
Encode search terms or filter values when passing them as URL parameters.
API Requests
Use when sending data containing special characters to REST APIs.
Form Data
HTML forms automatically encode data when submitted via GET method.
Share Links
Encode titles or descriptions with special characters for social media sharing.
Frequently Asked Questions
Q. Why is URL encoding necessary?
URLs were originally designed to use only ASCII characters. To include special characters or non-ASCII text in URLs, they must be converted to %XX format so browsers and servers can process them correctly.
Q. Is space %20 or +?
In URL paths, spaces are encoded as %20. In form data (application/x-www-form-urlencoded), spaces may be represented as +. Generally, using %20 is safer.
Q. Should I use encodeURIComponent or encodeURI?
Use encodeURIComponent when encoding query parameter values. Use encodeURI for complete URLs, but in most cases, encodeURIComponent is safer.
Q. Is it a problem if URLs become long with %XX encoding?
Long encoded URLs work fine functionally. Browsers display them decoded in the address bar for readability. However, some older systems may have URL length limits.
What is URL Encoding?
URL encoding (percent encoding) is a standard method for converting characters that cannot be used in URLs into safe ASCII format using %XX notation. It is essential when passing non-ASCII characters, spaces, and special characters in links or query parameters — ensuring browsers and servers exchange data accurately. When you see Korean text like '한글' appear as %ED%95%9C%EA%B8%80 in a URL, that is percent encoding in action.
This free online URL encoder/decoder instantly handles percent encoding and decoding. Beyond encodeURIComponent and encodeURI, it also provides HTML entity conversion, a URL parser (splits protocol, domain, path, and query parameters), double encoding detection, and multi-line batch processing — everything a developer needs in one place. Handle URL escape, query string encoding, and URL parameter encoding all at once.
Key Features
Real-time Encode/Decode
Enter text to instantly see URL encoding/decoding results. Supports both encodeURIComponent (for parameters) and encodeURI (for full URLs).
HTML Entity Mode
Supports HTML entity encoding (&, <, >, etc.) in addition to URL encoding. Useful for safely displaying special characters in web pages.
URL Parser & Query Editor
Enter a URL to automatically parse protocol, domain, path, and query parameters. Edit query parameters directly and generate new URLs.
Double Encoding Detection
Automatically detects and warns when trying to encode an already encoded string. Prevents common development mistakes.
How to Use
Select Mode — Choose encode or decode mode at the top.
Select Encoding Type — Choose Component (for parameter values, recommended) or URI (for complete URLs).
Enter Text — Paste the URL or text you want to convert in the input field.
Convert — Click the convert button to see the result.
Copy Result — Click the copy button to copy the result to your clipboard.
Use Cases
Web Development (API Parameters)
URL encoding is essential when sending search terms or data with special characters to REST APIs. Ensures safe transmission of query parameter values.
SEO (Clean URL Management)
Fix issues where non-ASCII characters appear broken in search engine URLs. Decode encoded URLs to verify their readable form.
Data Transmission & Form Handling
When HTML forms submit via GET method, browsers automatically URL-encode the data. Servers decode it to restore the original values.
Debugging Encoded URLs
Decode %XX formatted URLs from server logs or network monitors to quickly understand the actual request content.
Frequently Asked Questions
Q. Why is URL encoding necessary?
URLs were originally designed to use only ASCII characters. To include special characters or non-ASCII text in URLs, they must be converted to %XX format so browsers and servers can process them correctly.
Q. Is space %20 or +?
In URL paths, spaces are encoded as %20. In form data (application/x-www-form-urlencoded), spaces may be represented as +. Generally, using %20 is safer.
Q. Should I use encodeURIComponent or encodeURI?
Use encodeURIComponent when encoding query parameter values. Use encodeURI for complete URLs, but in most cases, encodeURIComponent is safer.
Q. Is it a problem if URLs become long with %XX encoding?
Long encoded URLs work fine functionally. Browsers display them decoded in the address bar for readability. However, some older systems may have URL length limits.
Q. What is double encoding?
Double encoding occurs when an already encoded string is encoded again. For example, %20 (space) becomes %2520. If the server decodes only once, it gets the encoded string instead of the original value. This tool automatically detects double encoding and warns you.
Q. Why does a URL with Korean characters look like %ED%95%9C%EA%B8%80?
Korean characters (and other non-ASCII text) in URLs are percent-encoded per RFC 3986. For example, '한글' becomes %ED%95%9C%EA%B8%80. Modern browsers decode these back to readable text in the address bar, but the actual request is sent in encoded form. Paste any %XX-encoded URL into this tool to instantly decode it back to the original text.
Privacy Notice
This URL encoder/decoder processes all data within your browser. The URLs or text you enter are never sent to any server. No information is stored or collected. You can safely convert URLs containing API keys or authentication credentials.