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URL Encoder / Decoder — Percent-Encoding Tool

Encode plain text or URLs into percent-encoded format, or decode percent-encoded strings back to readable text. Supports both standard URL encoding and component encoding for query parameter values. Everything runs in your browser — nothing is sent to a server.

About this tool

This tool encodes plain text into URL percent-encoding, or decodes percent-encoded strings back into readable text. You can choose between standard encoding (which preserves URL structure characters like / ? &) and component encoding (which also encodes those characters, making it suitable for individual query parameter values). Both operations run instantly in your browser.

How to use

  1. Paste your text or URL into the input field — the result updates as you type.
  2. Choose Encode or Decode using the tabs.
  3. Toggle "Component encoding" on to encode & = ? / as well (for query parameter values).
  4. Copy the result.

When to use this tool

  • Encoding a query parameter value that contains spaces, accents, or special characters before using it in an API call.
  • Decoding a percent-encoded URL from a log file or error message to make it readable.
  • Preparing non-ASCII characters for use in a web request or form submission.
  • Encoding a full URL before embedding it as a parameter value inside another URL.

Frequently asked questions

What is percent-encoding?

It replaces characters not allowed in URLs with a % sign followed by their two-digit hex code. For example, a space becomes %20.

When should I use "Component encoding"?

When encoding an individual query parameter value — it also encodes &, =, ?, and /, preventing them from being misinterpreted as URL structure characters.

Should I encode the entire URL or just parameter values?

Encode only individual query parameter values. Encoding the full URL (including slashes and colons) will break its structure.

Is my text sent to a server?

No. All processing runs in your browser using JavaScript's built-in functions. Nothing is transmitted.

Does this work offline?

Yes. Once the page has loaded, all processing runs locally.

Why do I get an error when decoding?

The input contains an invalid percent-encoded sequence — a % not followed by two hex digits, or an invalid UTF-8 sequence.

What is the difference between standard and component encoding?

Standard encoding preserves URL structure characters (/ ? & etc). Component encoding also encodes those characters, suitable for individual query parameter values.

Is this tool free?

Yes, completely free with no sign-up required and no usage limits.

Everything is processed locally in your browser — the text is never sent to a server.