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    URL Encoder & Decoder

    Encode string parameters for safe URL transmission or decode percent-encoded URLs back into readable text. Free online web tool.

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    About URL Encoder & Decoder

    URLs are restricted to a safe subset of ASCII characters. When web applications pass query parameters containing spaces, symbols, or non-English characters, those characters must be converted using percent-encoding (e.g. spaces become `%20`, `&` becomes `%26`). Without encoding, special characters can break URL structure, cause parameter injection, or produce unexpected API behavior.

    Automarkly URL Encoder & Decoder provides instant percent-encoding and decoding for developers, marketers, and web analysts inspecting web traffic links and API endpoints. The tool implements the standard `encodeURIComponent` and `decodeURIComponent` functions defined in RFC 3986, ensuring full compliance with URI encoding standards across all browsers and platforms.

    Understanding the difference between `encodeURI` and `encodeURIComponent` is essential for proper URL handling. `encodeURI` is designed for full URIs and leaves reserved characters like `/`, `?`, and `#` intact. `encodeURIComponent` encodes everything, including reserved characters, making it the correct choice for individual query parameter values. Our tool uses `encodeURIComponent` for maximum safety.

    Common use cases include encoding API query parameters with special characters, decoding tracked URLs from analytics platforms, preparing redirect URLs for OAuth flows, and sanitizing user input before constructing URL strings. Marketers use it to inspect and fix tracking URLs from tools like Google Analytics, Facebook Pixel, and email marketing platforms that append complex query strings.

    For developers building REST APIs, URL encoding is non-negotiable. A query parameter containing `&` without encoding will be interpreted as a parameter separator, splitting the value and corrupting the request. Similarly, spaces, quotes, and non-ASCII characters (like accented letters or emoji) must be encoded to ensure correct transmission across proxy servers, CDNs, and load balancers.

    Everything executes locally inside your browser. Confidential API tokens, internal URLs, and sensitive query parameters are never sent over the network. This makes the tool safe for use with production credentials, internal infrastructure links, and proprietary API endpoints. The tool is free with no registration, no limits, and no tracking.

    How to Use URL Encoder & Decoder

    1

    Enter or paste your web link, parameter value, or encoded string.

    2

    Click 'Encode URL' to escape spaces and special characters with percent-encoding.

    3

    Click 'Decode URL' to convert `%20` and escape sequences back into readable text.

    4

    Copy your output URL string with a single click.

    Key Benefits

    Standard Compliance: Uses standard RFC 3986 percent-encoding standards.
    Two-Way Conversion: Toggle smoothly between encoding and decoding URL query parameters.
    Instant Execution: Immediate output calculation in browser memory.
    Client-Side Privacy: Confidential API tokens and URLs are never sent over the network.
    100% Free: Unlimited usage for developers, QA testers, and SEO analysts.

    Common Use Cases

    Encoding a URL with special characters: https://example.com/search?q=hello world&lang=en becomes https://example.com/search?q=hello%20world%26lang%3Den — safe for use in HTTP requests.
    Encoding a redirect URI for OAuth: https://myapp.com/callback?state=abc123 becomes https%3A%2F%2Fmyapp.com%2Fcallback%3Fstate%3Dabc123 — properly encoded for the OAuth redirect parameter.
    Decoding a percent-encoded URL: https%3A%2F%2Fexample.com%2Fpath%3Fq%3Dtest decodes to https://example.com/path?q=test — useful for debugging URL parameters.
    Encoding a query parameter with special characters: q=café & résumé becomes q=caf%C3%A9%20%26%20r%C3%A9sum%C3%A9 — properly handles Unicode and special characters.
    Encoding an API key in a URL parameter: key=ab cd/ef becomes key=ab%20cd%2Fef — prevents the slash from being interpreted as a path separator.

    Frequently Asked Questions

    What is URL encoding (percent-encoding)?

    URL encoding replaces unsafe ASCII characters with a `%` followed by two hexadecimal digits representing the character code.

    Why do spaces become %20 or + in URLs?

    %20 is the standard percent-encoding representation for a space character in URL paths and parameters.

    Is Automarkly URL Encoder completely free?

    Yes, 100% free with zero registration required.

    Tips & Best Practices

    Always encode user input before inserting it into URL strings to prevent parameter injection attacks.
    Double-encoding can occur if you encode a string that's already encoded — check before re-encoding.
    When building redirect URLs for OAuth flows, encode the entire redirect_uri parameter value.
    Spaces can be encoded as %20 (standard) or + (form-urlencoded) — use %20 for URL paths and + for form data.
    Non-ASCII characters like accented letters and emoji are encoded as multi-byte percent-sequences (e.g. %C3%A9 for é).

    Conclusion

    The URL Encoder & Decoder ensures your URLs and query parameters are safely encoded for transmission across the web, preventing broken links, parameter injection, and API errors. Whether you're building REST APIs, inspecting tracking URLs, or sanitizing user input, this tool handles RFC 3986-compliant percent-encoding instantly in your browser. Explore our related developer tools for more resources.

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