URL デコーダー

デコード Percent-Encoded URLs & Query Strings

URLs can't contain certain characters—spaces, special punctuation, non-ASCII characters. So ブラウザs and servers percent-encode them: replacing special characters with % followed by their hexadecimal code. A space becomes %20, a slash becomes %2F, and emoji become multi-character sequences. When you copy URLs from ブラウザs or logs, they often appear heavily encoded and are nearly unreadable. This URL デコードr instantly 変換s them back to human-readable form.

Drop in an encoded URL or query string and see the original, デコードd version immediately.

What Gets デコードd

Percent-Encoded Characters: Any %XX sequence (where XX is hex) 変換s back to its character:

• %20 → space
• %2F → /
• %3A → :
• %26 → &
• And so on for all 256 possible byte values

Unicode Sequences: Multi-byte UTF-8 encoded characters (like emoji or non-ASCII characters) are properly reassembled from their percent-encoded parts.

Preserves Structure: The rest of the URL (scheme, domain, path, fragment) remains intact, so you get a fully readable URL.

Why You Need This

URL Inspection: ブラウザ address bars often show デコードd URLs, but logs, API responses, and HTTP headers show encoded versions. Decoding makes them readable for debugging.

API Debugging: When inspecting API requests and responses, URLs are percent-encoded. デコード them to understand what URLs were being called and what parameters were sent.

Log Analysis: Server logs, ブラウザ console logs, and request logs all contain percent-encoded URLs. Decoding helps you quickly understand which resources were accessed.

Query Parameter Inspection: URL query strings are heavily encoded. デコード the entire URL to see parameter names and values clearly:

• Encoded: https://example.com/search?q=hello%20world&category=tech%2Fai
• デコードd: https://example.com/search?q=hello world&category=tech/ai

Redirect Debugging: When investigating redirects, encoded redirect URLs are hard to read. デコード them to understand where the redirect goes.

Error Reporting

If the URL contains malformed encoding (odd number of hex digits after %, invalid hex characters, etc.), the tool reports the specific error. This helps you identify and fix encoding issues.

Common Debugging Scenarios

Network Tab Inspection: Copy a URL from the ブラウザ DevTools Network tab (which shows encoded URLs) and paste it here to read it clearly.

CI/CD Logs: Deployment logs often contain percent-encoded URLs. デコード them to verify the right resource was accessed.

Email URLs: URLs in emails are sometimes encoded. デコード to verify they're safe before clicking.

Database Content: If URLs are stored in your database, they may be encoded. デコード them for readability and verification.

OAuth & API Flows: Redirect URLs in OAuth flows and API documentation are often percent-encoded. デコード to understand the flow.

One-Click Copy

デコードd output copies to your クリップボード with a single click. Paste directly into your ブラウザ, documentation, or testing tools.

100% Local Decoding

Decoding happens entirely in your ブラウザ using standard JavaScript functions. Your URLs never leave your machine, so you can safely デコード URLs containing sensitive inフォーマットion, internal paths, or proprietary data.