URL Encoder & Decoder — Encode Query Strings

How to use URL Encoder & Decoder — Encode Query Strings

Three simple steps, with your content kept on your device.

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What is URL encoding?

URL encoding, also called percent encoding, replaces characters that are not safe inside a URL with a percent sign followed by their two-digit hexadecimal byte value. For example, a space becomes %20 and the ampersand becomes %26.

It exists because URLs may only contain a limited set of characters. Text that includes spaces, symbols, or non-Latin letters must be encoded before it can be placed in a URL, a query string, or an HTTP request.

URL encode vs URL decode

Encoding converts unsafe characters into percent-encoded sequences so the value can travel in a URL. Decoding converts those sequences back into the original characters. The two directions are exact opposites, so encoding followed by decoding always returns the original input.

This tool supports both directions: paste a value and encode it for a query string, or paste an encoded URL and decode it to read the original text. Whether you need to decode a URL that a website produced or encode a value before sending it, the page handles it locally.

How the encoder works in your browser

Valestiom uses the browser's native encodeURIComponent and decodeURIComponent functions, so the transformation is standard and instant. The input never leaves your device — there is no server involved.

Because the tool works on URL components, it is ideal for encoding query values, form parameters, and text you plan to insert into a URL. Encoding a complete URL also escapes its separators, which is expected behavior for component-level encoding.

When do you need percent encoding?

Any time you build a URL by hand — a search query, a redirect target, a share link, or an API parameter — characters like spaces, slashes, and ampersands must be percent-encoded to keep the URL valid and unambiguous.

Frameworks and browsers usually encode automatically, but debugging a link, generating a static redirect, or working with query parameters is where a manual encoder is genuinely useful.

Malformed percent sequences

A valid percent escape is a percent sign followed by exactly two hexadecimal digits, such as %20. A percent sign followed by anything else is malformed and cannot be decoded reliably.

This tool reports malformed sequences as a clear error instead of silently changing the input, so you always know whether the value decoded correctly.

Common characters and their encoding

The most frequent encodings are %20 for a space, %2F for a slash, %3F for a question mark, and %26 for an ampersand. Non-ASCII characters such as Persian or Chinese letters become multi-byte percent sequences.

When a URL looks broken or a query value arrives truncated, decoding it with this tool shows exactly which characters were escaped and what the original value was supposed to be.

URL encoding in query strings

Query strings are the part of a URL after the question mark, built from key=value pairs separated by ampersands. Any value that contains a space, an ampersand, or an equals sign must be encoded so the pairs stay unambiguous.

A practical workflow: compose your value, encode it with this tool, paste it into the query string, and later decode the full parameter to verify it survived the trip intact.

Encoding values for web forms and APIs

Web forms and APIs receive query parameters as encoded text. If a value contains characters like spaces, ampersands, or non-ASCII letters, it must be encoded before submission so the server receives exactly what the user typed.

When an API returns a value that looks like %E2%9C%93, decoding it with this tool reveals the original character — a checkmark — and confirms the encoding worked as intended. The same page also lets you encode a url value before placing it in a request, and acts as a url decoder whenever you need to read an encoded parameter back. No matter which direction you need — encode url text for a link, or decode an escaped value — the transformation happens instantly.

Troubleshooting encoded links

A broken link or a garbled parameter is often a mis-encoded URL. Decoding the suspicious value shows which characters were escaped and whether the encoding scheme matched the context — for example, whether a slash was encoded when it should have stayed literal.

This tool handles the standard component-level encoding used by browsers and web frameworks, which is the right choice for query values and path fragments.

Frequently asked questions