Dev Tool

URL Encoder & Decoder

Encode or decode URLs and query strings instantly. Supports percent encoding and Base64 URL encoding.

Input0 chars

Output0 chars

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URL Encoding

Converts special characters into % followed by two hex digits. Spaces become %20. Required for safe URLs.

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Component Encoding

encodeURIComponent encodes everything except A-Z a-z 0-9 - _ . ! ~ * ( ). Use for query string values.

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Base64 URL

Encodes binary data as ASCII text using URL-safe characters. Used in JWTs, API tokens and file sharing.

Frequently Asked Questions

When do I need to URL encode a string?

You need to URL encode strings when including special characters such as spaces, ampersands, equals signs, or non-ASCII characters in a URL query parameter. Unencoded special characters can break URL parsing and cause requests to fail or be misinterpreted by servers.

What is the difference between URL encoding and Base64 encoding?

URL encoding (percent-encoding) replaces special characters with a percent sign followed by their hexadecimal value, making strings safe for use in URLs. Base64 encoding converts binary data to an ASCII string and is used for embedding data in text formats. They serve different purposes and are not interchangeable.

Does this tool encode spaces as + or %20?

The tool uses standard percent-encoding which represents spaces as %20. Some older form-encoded formats use + for spaces, but %20 is the correct encoding for URL path and query components per RFC 3986. Both are decoded by most servers, but %20 is the safer and more standards-compliant choice.

What is URL encoding?

URL encoding (percent encoding) converts characters that are not allowed in URLs into a safe format. For example, spaces become %20, ampersands become %26. This ensures URLs are transmitted correctly across the internet.

What is the difference between encodeURI and encodeURIComponent?

encodeURI encodes a complete URL, leaving characters like / : ? & intact. encodeURIComponent encodes everything except alphanumeric characters and - _ . ! ~ * — use it for individual query string parameter values.

When should I use Base64 URL encoding?

Base64 URL encoding is used when you need to transmit binary data as text in a URL-safe format. Common uses include JWT tokens, OAuth state parameters, file attachment IDs, and API authentication tokens.

Why URLs need encoding

A URL can only contain a limited set of characters. Spaces, accented letters and symbols such as &, ?, # and = are either not allowed or have a special meaning, so they are written as a percent sign followed by two hexadecimal digits. A space becomes %20, & becomes %26 and é becomes %C3%A9. This tool encodes and decodes text that way, entirely in your browser.

When you need it

Query string values. A search term like salt & pepper must be encoded, or the & starts a new parameter and the value is cut short.
URLs inside URLs. A full address passed as a parameter, such as ?next=https://..., must be encoded so its own ? and & do not break the outer URL. Anonymiz links work exactly this way.
Reading logs and analytics. Decoding turns long strings of %XX codes back into readable search terms and paths.

Common mistakes

Double encoding. Encoding an already encoded string turns %20 into %2520. If you see %25, something was encoded twice.
Encoding the whole URL. Encode the values, not the https:// and slashes that give the URL its structure.
Plus signs. In form data a space is sent as +, so a real plus sign must be encoded as %2B or it turns into a space.