Free Online URL Encoder & Decoder — Instant Encoding

Encode or decode URLs instantly with this free online tool. Convert special characters to percent-encoded format for safe use in URLs, query strings, and API requests — or decode encoded URLs back to human-readable text. Everything runs in your browser.

TL;DR: Encode or decode URLs instantly in your browser using JavaScript’s built-in encodeURI, encodeURIComponent, and their decode counterparts. Supports full URL encoding, component encoding, and batch processing — no server, no signup.

How to Use

1. Encode URL — uses encodeURI(), keeps URL structure characters (://?#) intact
2. Encode Component — uses encodeURIComponent(), encodes everything except letters, digits, and - _ . ~
3. Decode URL — converts percent-encoded sequences (%20, %3D, etc.) back to readable characters

What Is URL Encoding?

URL encoding (also called percent encoding) replaces unsafe characters in a URL with a % followed by two hexadecimal digits representing the character’s byte value. For example, a space becomes %20 and an ampersand becomes %26.

When to Use Which Method

• encodeURI() — Use for encoding a full URL. Preserves : / ? # [ ] @ ! $ & ' ( ) * + , ; =
• encodeURIComponent() — Use for encoding a single query parameter value. Encodes everything except A-Z a-z 0-9 - _ . ~

Common Encoded Characters

• %20 — Space
• %26 — Ampersand (&)
• %3D — Equals (=)
• %3F — Question mark (?)
• %2F — Forward slash (/)
• %23 — Hash (#)
• %25 — Percent sign (%)

Privacy

This tool runs 100% client-side in your browser using built-in JavaScript functions. No data is transmitted to any server.

Recommended Reading

Deepen your understanding of URLs, HTTP, and web security:

• HTTP: The Definitive Guide — essential reading for understanding URLs and HTTP
• Web Security for Developers — essential reading for URL injection and encoding attacks
• Learning Web Design — essential reading for HTML forms and URL parameters

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Frequently Asked Questions

What is the difference between encodeURI and encodeURIComponent?

encodeURI() encodes a full URL but preserves structural characters like :, /, ?, #, and &. encodeURIComponent() encodes everything except unreserved characters (letters, digits, -_.~), making it suitable for encoding individual query parameter values.

Why do I need to percent-encode URLs?

URLs can only contain a limited set of ASCII characters. Characters like spaces, Unicode text, and reserved symbols must be percent-encoded (e.g., space → %20) to be transmitted safely in HTTP requests, query strings, and hyperlinks as defined by RFC 3986.

Does this tool handle Unicode and emoji in URLs?

Yes. JavaScript’s encoding functions convert Unicode characters to their UTF-8 byte sequences and then percent-encode each byte. For example, the emoji 🚀 becomes %F0%9F%9A%80.

Is my data sent to a server?

No. All encoding and decoding runs entirely in your browser using JavaScript. Your input never leaves your device.

References

• MDN — encodeURIComponent() — JavaScript reference for percent-encoding URL components
• RFC 3986 — Uniform Resource Identifier (URI): Generic Syntax — The IETF standard defining URI syntax and percent-encoding rules
• MDN — encodeURI() — JavaScript reference for encoding full URIs while preserving structure characters
• W3C — Internationalized Resource Identifiers (IRIs) — How Unicode and international characters are handled in web addresses