URL Encoder / Decoder - Encode and Decode URLs Free Online
What is URL Encoding and Decoding?
URL encoding (also called percent-encoding) converts special characters in URLs into a format that can be safely transmitted over the internet. URLs can only contain certain characters from the ASCII set, so any character outside that range—including spaces, symbols, and non-Latin characters—must be encoded as %XX where XX is the hexadecimal value.
URL decoding reverses this process, converting encoded characters (%20, %3F, etc.) back to their original form. Whether you're building web applications, debugging API calls, working with query parameters, or analyzing URLs, this tool makes encoding and decoding instant and error-free.
Our URL Encoder / Decoder offers:
- Instant Encoding: Convert any text to URL-safe format with one click
- Instant Decoding: Convert encoded URLs back to readable text
- Bidirectional Operation: Switch between encode and decode modes instantly
- Handles All Characters: Properly encodes spaces, symbols, Unicode, emoji, and special characters
- Real-Time Processing: See results as you type or paste
- Client-Side Processing: Complete privacy—text never leaves your browser
- No Limits: Process URLs and query strings of any length
Why URL Encoding is Essential
🔗 URL Structure and Standards
URLs follow strict syntax rules defined by RFC 3986:
- Only certain ASCII characters are allowed in URLs without encoding
- Reserved characters (?&=/#:;) have special meanings and must be encoded when used as data
- Spaces and most symbols break URLs if not encoded
- Non-ASCII characters (accents, Chinese, Arabic, emoji) must always be encoded
- Unencoded special characters cause parsing errors and broken links
🌐 Web Development and APIs
Proper URL encoding is critical for applications:
- Query parameters with user input must be encoded to prevent injection attacks
- API requests with special characters in parameters fail without encoding
- Form submissions with spaces or symbols require proper encoding
- OAuth and authentication systems break with improperly encoded redirect URLs
- Analytics and tracking parameters need encoding to preserve data integrity
🔍 Debugging and Analysis
Decoding URLs helps understand and troubleshoot:
- Decode URL parameters to see actual values being passed
- Understand what data is being transmitted in URLs
- Debug API calls by inspecting encoded parameters
- Analyze tracking URLs and marketing campaign parameters
- Troubleshoot broken links caused by encoding issues
🛡️ Security and Data Integrity
Encoding protects against security vulnerabilities:
- Prevents URL injection attacks by properly encoding user input
- Protects against cross-site scripting (XSS) in URL parameters
- Ensures data integrity when passing information via URLs
- Prevents parameter pollution and manipulation
- Maintains correct data when URLs pass through proxies and servers
How URL Encoding Works
URL Encoding Process
Each character is converted to its percent-encoded form:
- Character is converted to its UTF-8 byte representation
- Each byte is represented as %XX where XX is two hexadecimal digits
- Certain "unreserved" characters (A-Z, a-z, 0-9, -, _, ., ~) are never encoded
- Reserved characters are encoded when used as data, not as delimiters
Common Character Encodings
| Character | Description | Encoded As |
|---|---|---|
| (space) | Space | %20 |
| ! | Exclamation | %21 |
| " | Quote | %22 |
| # | Hash | %23 |
| $ | Dollar | %24 |
| % | Percent | %25 |
| & | Ampersand | %26 |
| + | Plus | %2B |
| = | Equals | %3D |
| ? | Question | %3F |
| @ | At | %40 |
| / | Slash | %2F |
| : | Colon | %3A |
| ; | Semicolon | %3B |
| [ | Left bracket | %5B |
| ] | Right bracket | %5D |
Step-by-Step: How to Use URL Encoder / Decoder
Choose Encode or Decode
Select "Encode" if you have plain text that needs to be URL-safe, or "Decode" if you have an encoded URL that you want to make readable. Switch between modes instantly.
Paste Your Text or URL
Paste your text, URL, or query string into the input field. The tool handles any length—from single parameters to complete URLs with multiple query strings.
View Real-Time Results
The encoded or decoded result appears instantly as you type or paste. No need to click a button—processing is automatic and real-time.
Copy and Use
Click "Copy" to copy the result to your clipboard. Use the encoded URL in your application, API call, link, or wherever URL-safe text is required.
Use Cases: When to Use URL Encoding and Decoding
🔗 Building Query Parameters
Scenario: Creating search URLs with user input.
Problem: User searches for "cats & dogs" and you need to construct: ?q=cats & dogs
Without encoding, the & breaks the URL, creating two parameters instead of one search term.
Solution: Encode "cats & dogs" to "cats%20%26%20dogs" → ?q=cats%20%26%20dogs works correctly.
🌐 API Development and Testing
Scenario: Calling REST APIs with parameters containing special characters.
Problem: API endpoint like /users?email=user@example.com fails because @ isn't encoded.
Solution: Encode email to "user%40example.com" → /users?email=user%40example.com works. Essential for API testing, webhook URLs, and OAuth redirect URIs.
🔍 Debugging and Log Analysis
Scenario: Analyzing server logs or debugging failed requests.
Problem: Log shows: GET /search?q=hello%20world%26greeting%3Dhi
Solution: Decode to see actual parameters: q="hello world" and greeting="hi". Instantly understand what data was actually sent without mental decoding.
📧 Email Marketing and Tracking URLs
Scenario: Creating tracking URLs with campaign parameters.
Problem: Campaign name is "Q1 2024: New Products!" with special characters.
Solution: Encode to "Q1%202024%3A%20New%20Products%21" for UTM parameter. Ensures analytics platforms correctly track the full campaign name.
🔐 OAuth and Authentication
Scenario: Setting up OAuth redirect URIs or state parameters.
Problem: Redirect URL contains query parameters that themselves need encoding.
Solution: Double-encode redirect URLs: first encode the full redirect URL, then include it as a parameter. Critical for OAuth flows and SSO implementations.
🌍 Internationalization (i18n)
Scenario: URLs with non-English characters.
Problem: User searches in Chinese "北京" or Arabic "مرحبا" and URL breaks.
Solution: Encode Unicode characters: "北京" → "%E5%8C%97%E4%BA%AC". Ensures international content works correctly in URLs worldwide.
📱 Mobile Deep Links
Scenario: Creating deep links for mobile apps with data parameters.
Problem: Passing data like titles or descriptions through deep link URLs.
Solution: Encode all data parameters to prevent breaking the deep link format. Essential for share links, referral links, and app-to-app communication.
🔎 SEO and URL Structure
Scenario: Creating SEO-friendly URLs with readable slugs.
Problem: Article title "How to Use C++ Effectively?" needs to become a URL slug.
Solution: Encode special characters while keeping structure: "How-to-Use-C%2B%2B-Effectively%3F". Balances readability with technical correctness.
Privacy and Security
🔒 Complete Privacy
All encoding and decoding happens in your browser using JavaScript. Your URLs never leave your device, never get uploaded, never get logged.
🚫 No Data Collection
We don't log, analyze, or store any URLs or text you process. No tracking. Your content remains completely private.
💯 No Registration
No account, no email, no sign-up. Just paste and encode/decode instantly. Use unlimited times, completely free.
⚡ Instant Processing
Processing is local with no server delay. Encode or decode URLs of any length instantly with real-time results.
Start Encoding and Decoding URLs Now
Our free URL encoder/decoder is ready to use at the top of this page. No download, no account, no limits. Simply paste your text or URL, choose encode or decode, and get instant, accurate results.
Whether you're building web applications, debugging APIs, analyzing URLs, creating tracking links, or handling international content, our tool provides fast, reliable URL encoding and decoding with complete privacy.
✨ Quick Start
- ✓Choose Encode or Decode mode
- ✓Paste your text or URL
- ✓See instant real-time results
- ✓Copy and use in your project!
Frequently Asked Questions About URL Encoding and Decoding
1. What's the difference between URL encoding and Base64 encoding?
URL encoding (percent-encoding) is specifically designed for URLs and converts characters to %XX format (e.g., space → %20). It's primarily for making URLs safe and parseable. Base64 encoding converts binary data to ASCII text using A-Z, a-z, 0-9, +, / characters, typically for email attachments or embedding binary data in JSON/XML. URL encoding is for URL safety; Base64 is for data transmission. They serve different purposes and aren't interchangeable. For URLs and query parameters, always use URL encoding, not Base64.
2. When should I encode URLs vs. when to leave them as-is?
Encode when: (1) User input goes into URL parameters (search terms, form data), (2) Text contains special characters (& = ? # / :), (3) Non-ASCII characters (unicode, accents, emoji), (4) Spaces or symbols in any part of the URL, (5) Building URLs programmatically. Don't encode: (1) The protocol (http://), (2) The domain (example.com), (3) Path separators (/ between path segments), (4) Parameter separators (? and & between params), (5) Already-encoded URLs (avoid double-encoding). Rule of thumb: encode data values, not URL structure.
3. What is double encoding and how do I avoid it?
Double encoding happens when you encode an already-encoded string, turning %20 into %2520 (the % itself gets encoded to %25). This breaks URLs because the server decodes only once, leaving %2520 instead of recovering the original space. To avoid: (1) Always decode before encoding again if unsure, (2) Track whether data is already encoded, (3) Use our tool to decode first, inspect, then encode fresh if needed, (4) Never apply encoding functions twice to the same data. If a URL isn't working, check if it's double-encoded by decoding twice and seeing if it makes sense.
4. Why does my URL have + instead of %20 for spaces?
Both + and %20 represent spaces, but they're used in different contexts. + is the older "application/x-www-form-urlencoded" format used in form submissions and some query strings. %20 is the standard percent-encoding used everywhere else. Modern best practice: use %20 everywhere for consistency. However, many systems still accept + for spaces in query parameters for backwards compatibility. Our tool uses standard %20 encoding. If you receive + for spaces, they decode correctly. When building new systems, prefer %20 for clarity and universal compatibility.
5. Can I encode an entire URL at once?
No! You should NEVER encode an entire URL including the protocol and domain. Encoding the full URL turns "https://example.com/search?q=hello" into unreadable garbage that doesn't work. Instead, encode only the data parts: parameter values, path segments with special characters, etc. Structure breakdown: "https://" (never encode), "example.com" (never encode), "/search" (usually don't encode), "?q=" (never encode), "hello world" (encode to "hello%20world"). Final URL: "https://example.com/search?q=hello%20world". Only encode the actual data values, preserve URL structure.
6. How do I handle multiple parameters with encoding?
Encode each parameter value separately, then join with proper delimiters. Example: Parameters are name="John Smith", email="user@example.com", query="cats&dogs". Process: (1) Encode name → "John%20Smith", (2) Encode email → "user%40example.com", (3) Encode query → "cats%26dogs", (4) Build URL: "?name=John%20Smith&email=user%40example.com&query=cats%26dogs". The & between parameters stays unencoded (it's structure), but & within values gets encoded to %26. Never encode the ? or & that separate parameters, only encode the values themselves.
7. Why do I see %E2%80%99 instead of a simple apostrophe?
That's a "smart quote" or curly apostrophe ('), not the regular apostrophe ('). Many word processors and phones automatically convert straight quotes to curly quotes. The curly apostrophe is a Unicode character (U+2019) which encodes as three bytes in UTF-8: E2 80 99, becoming %E2%80%99 when URL-encoded. A regular apostrophe (') would be %27. This commonly happens when copy-pasting from Word, Google Docs, or phone messages. If you want the simple %27, replace curly quotes with straight quotes before encoding, or use our decoder to see what character you actually have.
8. Can I use this for encoding passwords or sensitive data in URLs?
NO! URL encoding is NOT encryption—it's just formatting. Encoded data is easily decoded by anyone who sees the URL. NEVER put sensitive data like passwords, API keys, credit cards, or personal information in URLs, even encoded. Why: (1) URLs appear in browser history, (2) URLs are logged by servers, proxies, and analytics, (3) URLs can be shared or bookmarked, exposing data, (4) Encoding provides zero security. Use POST requests with encrypted connections (HTTPS) for sensitive data. Only put non-sensitive identifiers in URLs. URL encoding protects URL integrity, not data confidentiality.
9. How do I decode URLs in programming vs. using this tool?
Our tool is perfect for quick manual decoding when debugging, analyzing links, or understanding URLs. For programming: JavaScript: use decodeURIComponent() and encodeURIComponent(). Python: use urllib.parse.unquote() and quote(). PHP: use urldecode() and urlencode(). Use our tool for: one-off testing, understanding what URLs contain, debugging without writing code, learning how encoding works. Use code for: automated processing, building applications, handling many URLs.
10. What's the difference between encodeURI() and encodeURIComponent()?
These are JavaScript functions with different purposes: encodeURI() encodes a complete URL, preserving structure characters like :/?#&=, meant for full URLs. encodeURIComponent() encodes everything including structure characters, meant for individual parameter values. Example: for value "http://example.com/page?x=1", encodeURI keeps it mostly readable; encodeURIComponent converts it to "http%3A%2F%2Fexample.com%2Fpage%3Fx%3D1" suitable for use as a parameter value. Our tool works like encodeURIComponent—it encodes everything for maximum safety. Use Component version for parameter values (most common case).
11. Why do emoji turn into so many %XX characters?
Emoji are complex Unicode characters that require multiple bytes in UTF-8 encoding. Example: 😀 (grinning face) is Unicode U+1F600, which encodes as 4 bytes in UTF-8: F0 9F 98 80, becoming %F0%9F%98%80 in URL encoding. More complex emoji with modifiers (skin tones, combined sequences) can become even longer—sometimes 20+ characters when encoded. This is normal and correct. When decoded, all those % sequences combine back into the single emoji character. This is why you should avoid emoji in URLs when possible—they make URLs very long and hard to read when encoded.
12. Can URL encoding break my website's functionality?
Improper encoding can definitely break things: (1) Double-encoding parameters makes servers receive wrong values, (2) Not encoding special characters breaks URL parsing, (3) Encoding structure (?, &, =) instead of just values breaks URLs, (4) Some older systems don't properly decode, causing issues, (5) Very long encoded URLs might exceed server limits (typically 2048 chars). Best practices: (1) Encode parameter values, not URL structure, (2) Test with special characters during development, (3) Decode on the server side to recover original values, (4) Never trust user input—always encode it before putting in URLs, (5) Keep URLs reasonably short even after encoding.
13. Is there a character limit for URL encoding?
The encoding process itself has no limit—you can encode any length text. However, the resulting URL has practical limits: (1) HTTP spec recommends max 2048 characters for entire URL, (2) Different browsers enforce different limits (IE: 2083, Chrome/Firefox: much higher), (3) Servers may impose their own limits, (4) Proxies and firewalls might truncate long URLs. Recommendation: keep total URL under 2000 characters to ensure universal compatibility. For very long data (>500 characters), use POST requests instead of GET with URL parameters. Our tool will encode any length, but use common sense for actual URLs.
14. How do I handle URL encoding for different character sets?
Modern URLs use UTF-8 encoding exclusively. Always encode using UTF-8, which handles all languages and characters correctly. Legacy systems occasionally used other encodings (ISO-8859-1, Windows-1252), but these are obsolete for URLs. Our tool uses UTF-8, the universal standard. This means: (1) English, European, Russian, Arabic, Chinese, Japanese, Korean all work correctly, (2) Emoji and special symbols encode properly, (3) URLs work consistently worldwide, (4) Modern browsers and servers expect UTF-8. If you encounter an old system requiring different encoding, you'll need specialized tools, but 99.9% of modern web applications use UTF-8.
15. Can I encode file paths for URLs?
Yes, but encode carefully. File paths in URLs need encoding for special characters while preserving path structure. Example: File path "docs/My Documents/Report #1.pdf" should become "docs/My%20Documents/Report%20%231.pdf". Notice: (1) / slashes stay unencoded (they're path separators), (2) Spaces → %20, (3) # → %23. For Windows paths with backslashes, convert \\ to / first, then encode: "C:\\Users\\John Smith" → encode to "C:/Users/John%20Smith". Never encode the path separators themselves. This is common for file download links, document viewers, and file sharing systems.
16. Why does decoding sometimes produce weird characters?
This usually means: (1) The URL was encoded with a different character set than you're decoding with (rare now with UTF-8 standard), (2) The URL is malformed with invalid percent sequences, (3) The URL wasn't actually encoded—the % symbols are literal, (4) The URL is double or triple-encoded and you need to decode multiple times. To fix: (1) Try decoding multiple times if you suspect multiple encoding layers, (2) Check if % symbols are actual percent signs (%%25 or %37 when encoded), (3) Verify the source—some systems output already-decoded URLs, (4) If characters look corrupted, the original encoding may be irrecoverable.
17. Is my data private when using this tool?
Completely private. All encoding and decoding happens entirely in your browser using JavaScript—your URLs and text never leave your device, never get uploaded to servers, never get logged, and never get stored anywhere. The tool works offline once the page loads, proving nothing is transmitted. This means you can safely process sensitive API URLs, OAuth parameters, tracking links, internal URLs, or any content without privacy concerns. Your data stays on your device from start to finish. No accounts, no tracking, no data collection whatsoever. Safe for confidential or proprietary URLs.
18. Does this work on mobile devices?
Yes, fully responsive for phones and tablets! To use on mobile: (1) Copy the URL or text you want to encode/decode, (2) Open our website in your mobile browser (Safari, Chrome, Firefox), (3) Choose Encode or Decode mode, (4) Paste your text, (5) See instant results, (6) Tap Copy to copy the result. The interface is touch-optimized and all processing happens locally on your device, so it works even with slow mobile connections. Perfect for quick URL encoding/decoding on the go when debugging mobile apps, testing deep links, or analyzing URLs without a computer.
19. How do I encode special characters that have specific meanings in URLs?
The "reserved" characters (: / ? # [ ] @ ! $ & ' ( ) * + , ; =) have special structural meanings in URLs. To use them as data (not structure), they must be encoded. Example: You want to search for "what?" including the question mark. The ? normally starts query parameters, so encode it: "what%3F". Similarly, & normally separates parameters, so "cats&dogs" must become "cats%26dogs" when used as a single value. Our tool automatically encodes all special characters correctly. The rule: anything that might confuse URL parsing must be encoded when used as data rather than URL structure.
20. Can this tool help with SEO and URL structure?
Yes! SEO-friendly URLs benefit from proper encoding: (1) Decode ugly URLs to understand their structure and content, (2) Encode clean, readable slugs that contain special characters, (3) Analyze competitor URLs to see their parameter structure, (4) Ensure international URLs (non-English characters) are properly encoded for global reach, (5) Debug tracking parameters (UTM codes) to verify analytics setup. SEO best practice: keep URLs readable (use dashes for spaces in slugs) but encode special characters that break URLs. Balance human-readability with technical correctness. Use our tool to test how URLs will actually appear and function.