Free URL Encoder and Decoder Online

How to use the URL encoder decoder online

1. Select Encode or Decode mode using the toggle at the top of the tool.
2. Paste your plain text or percent-encoded string into the input field.
3. The result appears instantly in the output panel with no button click required.
4. Click Copy to copy the result to your clipboard in one click.
5. Click Clear to reset both fields and start with a new input.

URL encode online: building safe query strings and API requests

URL encoding is required whenever you include user-provided text or dynamic values inside a URL. Characters like spaces, ampersands, equals signs, and slashes have structural meaning in URLs. If they appear inside a query parameter value without encoding, the browser or server will misparse the URL. The encode URL operation converts these characters to their percent-encoded equivalents so the URL structure stays intact and the data passes through correctly.

Common use cases for URL encode online: constructing API query strings that include search terms or addresses, building redirect_uri values for OAuth flows, encoding the target URL parameter in tracking links, passing email addresses or phone numbers in query parameters, and encoding filter values that contain special characters. Paste the value you want to include in the URL, encode it here, then concatenate the encoded result into your URL string. For QR codes that point to URLs with query parameters, encode the parameter values here before generating the code in the QR code generator.

URL decode online: reading encoded links and OAuth parameters

Decode URL online converts every %XX percent sequence back to its original character. Encoded URLs appear frequently in email tracking links, OAuth authorization responses, server access logs, copy-pasted browser address bar content, and API error messages that include encoded request paths. In encoded form these strings are difficult to read and debug. Pasting them into the decoder immediately reveals the plain-text content.

A common debugging scenario is inspecting OAuth 2.0 parameters. When an authorization server redirects back to your app, the redirect URL contains a state parameter and sometimes a redirect_uri parameter, both percent-encoded. Decoding them here shows the actual values being passed. JWT tokens embedded in URL parameters are Base64 URL-encoded rather than percent-encoded; use the Base64 decoder for those after stripping the URL encoding layer first.

What is URL encoding and how percent encoding works

URL encoding (percent encoding) is defined by RFC 3986. It converts each unsafe byte to a percent sign followed by two uppercase hexadecimal digits. A space (byte 0x20) becomes %20. An ampersand (byte 0x26) becomes %26. A forward slash (byte 0x2F) becomes %2F. Non-ASCII characters such as accented letters, Arabic, Chinese, and emoji are first converted to UTF-8 bytes, then each byte is percent-encoded. An emoji like a smiley face encodes to four percent sequences because it requires four UTF-8 bytes.

The four unreserved characters that are never encoded are hyphen (-), underscore (_), period (.), and tilde (~), along with all letters and digits. Note that + is not a percent-encoding for space in RFC 3986. It only means space in the older application/x-www-form-urlencoded format used by HTML form submissions. When in doubt, use %20 for spaces to stay compatible with all parsers.

JavaScript URL encode and decode

JavaScript has two pairs of built-in functions for URL encoding. encodeURIComponent(str) encodes a value for use inside a URL component (query parameter, path segment, fragment). It encodes everything except letters, digits, and - _ . ~. decodeURIComponent(str) reverses this. encodeURI(str) encodes a full URL but preserves structural characters like / ? & = : #. decodeURI(str) reverses that.

For constructing query strings in JavaScript, the modern approach is URLSearchParams: new URLSearchParams({ q: "hello world", page: 2 }).toString() returns q=hello+world&page=2 using the form-encoded format (spaces as +). When appending to a URL manually, prefer encodeURIComponent for each value and join with &. This tool applies the same logic as encodeURIComponent for encode mode and decodeURIComponent for decode mode.

Python URL encode and decode

Python's urllib.parse module is the standard library for URL encoding. To encode a single value: from urllib.parse import quote; quote("hello world & more") returns "hello%20world%20%26%20more". The safe parameter controls which characters to leave unencoded: quote(value, safe="") encodes everything except unreserved characters.

To build a full query string from a dictionary in Python: from urllib.parse import urlencode; urlencode({ "q": "search term", "page": 1 }) returns q=search+term&page=1. Python URL decode uses from urllib.parse import unquote; unquote("hello%20world") which returns hello world. The requests library encodes query parameters automatically when you pass a params dict to requests.get(), so manual encoding is only needed when constructing URLs as strings. For API responses that mix JSON and encoded values, the JSON formatter helps inspect the response structure after decoding.

URL encoding in API development and debugging

URL encoding issues are among the most common causes of broken API integrations. A missing or incorrect encoding step causes query parameters to be misread, search terms to be truncated at special characters, redirect URIs to fail OAuth validation, and file path parameters to resolve to wrong resources. The online URL encoder decoder is a quick diagnostic tool: if your API call is misbehaving, paste the problematic parameter value here, encode it, and compare the result to what your code is sending.

When working with HMAC-signed API requests, the string-to-sign must be constructed from the encoded form of each parameter value. Encoding errors in the string-to-sign cause signature mismatches even when the values themselves are correct. For APIs that use SHA-256 HMAC signatures (like AWS Signature V4 or Stripe webhook verification), the SHA hash generator lets you compute and verify hashes alongside the URL encoding step here.