URL Encoder and Decoder Toolv1.0.0

• Reserved characters (: / ? # [ ] @ ! $ & ' ( ) * + , ; =) may need encoding depending on context
• Unreserved characters (A-Z a-z 0-9 - . _ ~) are never encoded
• Spaces become %20 in standard encoding or + in form mode (application/x-www-form-urlencoded)
• Be cautious of double-encoding already encoded URLs
• Multiple URLs can be processed simultaneously when detected in the input
• UTF-8 encoding is used for international characters (e.g., café becomes caf%C3%A9)
• Use "Encode all" option to encode reserved characters that are normally preserved

Convert URLs and text to safe, percent-encoded formats or restore encoded strings to readable text. Protect query strings, form data, and API parameters from breaking characters. Improve reliability in browsers, scripts, and server-side code by applying standards-compliant URL encoding and decoding.

Process single values or large lists with fast, accurate output. Use form mode for application/x-www-form-urlencoded data, encode all non-unreserved characters for strict scenarios, and force double-encoding when a downstream system expects %25HH sequences. Copy results, export CSV, and audit differences to speed up debugging and reviews.

Convert readable text and URLs to safe web formats or restore percent-encoded strings to human-readable form. Follow these steps to match browser, API, and form behavior.

• Select Mode to set the operation. Choose Encode to percent-encode text or Decode to convert %HH sequences back to text. Let auto-detect switch modes when input clearly indicates the opposite action.
• Paste or type content in Enter URL or text. Track input length with the live Character Length counter.
• Enable Form mode to replace spaces with + for application/x-www-form-urlencoded data. Leave it off to encode spaces as %20.
• Enable Process each line separately to convert lists line by line, which helps when handling bulk URLs or parameters.
• Enable Encode all non-unreserved to encode reserved symbols that are usually preserved in URLs.
• Enable Force double-encode to re-encode existing %HH sequences as %25HH when a downstream system expects double encoding.
• Click Encode/Decode or turn on Live mode to run conversions automatically as you type or paste.
• Use Swap Input & Result to feed the output back into the input for chained conversions.
• Click Copy to place results on the clipboard. Click Download .txt Result or Download .csv Result to export single or multiple items.
• Toggle Show character map and differences to view a concise map of changed characters for quick audits.

Formulas and logic:

• Keep unreserved characters unchanged: A-Z a-z 0-9 - . _ ~.
• Encode spaces as %20 by default or as + in form mode.
• Write each byte as %HH using uppercase hexadecimal during percent-encoding.
• Encode non-ASCII characters as UTF-8 bytes and then percent-encode each byte.
• Decode by optionally converting + to space in form mode and then mapping each valid %HH to its byte before UTF-8 decoding.
• Apply Force double-encode to turn existing %HH into %25HH.
• Apply Encode all non-unreserved to encode reserved symbols :/?#[]@!$&'()*+,;= when strict encoding is required.

Prepare, validate, and troubleshoot URLs and text for web development, SEO, analytics, and system integration.

• Build clean query strings for GET requests and safely encode keys and values before sending requests to APIs and microservices.
• Prepare form payloads for application/x-www-form-urlencoded workflows by converting spaces to + and encoding special characters.
• Decode URLs in server logs to investigate redirects, missing pages, parameter corruption, and security filters.
• Bulk-convert lists from TXT or CSV during SEO audits, site migrations, and marketing tag cleanups.
• Handle Unicode in paths and parameters by confirming correct UTF-8 percent-encoding for internationalized content.
• Sanitize user input in scripts and low-code automations to prevent broken requests and inconsistent link handling.
• Verify webhook callback URLs and third-party redirect targets during QA, CI checks, and monitoring.
• Normalize links in analytics exports to consolidate metrics and reduce duplicate URL variants.

• Encode example: https://example.com/search?q=coffee & cream / café becomes https://example.com/search?q=coffee%20%26%20cream%20%2F%20caf%C3%A9.
• Decode example: name%3DJohn+Doe%26city%3DZ%C3%BCrich with form mode becomes name=John Doe&city=Zürich.
• Double-encode example: Enabling force double-encode turns %2F into %252F for systems that expect a second encoding pass.

When should I use form mode? Use form mode when you submit data with application/x-www-form-urlencoded, such as classic HTML forms and many OAuth flows, because spaces become + instead of %20.
Why do some characters stay unencoded? Unreserved characters A-Z a-z 0-9 - . _ ~ do not need encoding under RFC 3986. Enable Encode all non-unreserved to enforce stricter output.
Why do non-ASCII characters expand? UTF-8 represents them with multiple bytes, so each byte becomes a %HH sequence. This is correct and ensures cross-system compatibility.
What does double-encoding do? It converts existing %HH to %25HH for pipelines that intentionally require a second encoding layer.