URL Encoder & Decoder

URL Encoder & Decoder: Core Features and Principles

When you directly use non-ASCII characters, spaces, or special characters like & and ? in a URL, browsers and servers may fail to parse them correctly, leading to broken links or data loss. URL encoding (also known as percent-encoding) is a mechanism designed to solve this issue. It converts each unsafe character into a percent sign (%) followed by two hexadecimal digits. The core function of this tool is to perform this secure two-way conversion for URLs and their parameters, processing single characters (or multi-byte sequences in UTF-8 encoding) as the basic unit.

Why Choose Our URL Encoder & Decoder?

• Supports Mainstream Encoding Standards: Strictly follows both RFC 3986 (spaces to %20) and RFC 1738 (spaces to +) specifications, meeting the diverse needs of modern APIs and traditional form submissions.
• Fine-Grained Conversion Modes: When encoding, you can choose "Force Full Encoding", "Keep Unencoded Characters", or "Spaces to Plus Signs" to flexibly adapt to various application scenarios.
• Intuitive and Efficient: The interface clearly separates the encoding and decoding areas. Conversions are completed with a single click, requiring no complex configurations or command-line operations.

How to Use

1. Paste the original string or URL fragment you want to encode into the input text box.
2. Select the "RFC 3986" or "RFC 1738" encoding standard based on your target system's requirements.
3. If special handling is needed (e.g., spaces to +), select the corresponding option under the conversion settings.
4. Click the "Encode" button, and the result will instantly appear in the output area.
5. For decoding, simply do the reverse: paste the encoded content into the output box and click "Decode".

Frequently Asked Questions (FAQ)

Q: Should spaces in a URL be encoded as %20 or a plus sign (+)?
This depends on the application scenario. In most modern web standards and APIs (following RFC 3986), spaces should be encoded as %20. The plus sign (+) is primarily used for HTML form submissions (application/x-www-form-urlencoded format) or when interacting with legacy systems. This tool allows you to choose based on your needs.

Q: Does URL encoding change non-ASCII characters like Chinese?
Yes. Non-ASCII characters cannot be used directly in URLs. Based on the UTF-8 character set, this tool converts each non-ASCII character into a continuous sequence of percent-encoded values. For example, the Chinese characters "计算器" will be encoded as "%E8%AE%A1%E7%AE%97%E5%99%A8".

Important Notes

Please ensure you use the same standard (RFC 3986 or RFC 1738) for both encoding and decoding; otherwise, the results may be incorrect. Avoid encoding an already encoded string a second time (double encoding). When processing non-ASCII characters, verify that the source data is UTF-8 encoded to prevent garbled text. This tool processes text strings and does not support direct file uploads or batch file processing.

Technical Notes & Best Practices

For web developers, it is crucial to encode variable values when handling GET request parameters or dynamically generating URLs. A typical scenario: embedding the search keyword "price comparison" into a URL. Direct concatenation will cause spaces to be parsed incorrectly. The correct approach is to encode it as "price%20comparison" (RFC 3986) or "price+comparison" (form format). While you can use encodeURIComponent() in JavaScript or urllib.parse.quote() in Python to achieve similar functionality, this tool provides a more intuitive visual comparison and standard selection, making it ideal for debugging and verification.