Free Online URL Encoder & Decoder - Percent-Encoding & Parameter Parser
The Uniform Resource Identifier (URI) specification (RFC 3986) mandates that URLs can only contain a limited set of unreserved ASCII characters (`A-Z`, `a-z`, `0-9`, `-`, `_`, `.`, `~`). Special characters, spaces, non-ASCII international alphabets, and control characters must be converted into Percent-Encoding format (`%` followed by two hexadecimal digits) to prevent link corruption when sent over HTTP. Our Free Online URL Encoder & Decoder handles full URL strings, single query parameter components, and extracts query parameter tables.
Equipped with support for both `encodeURI()` and `encodeURIComponent()`, automatic query parameter extraction tables, and sample URL loaders, our tool processes all string transformations 100% locally in your web browser without transmitting web links over the internet.
How to Encode & Decode URLs Online
- Select Action Mode: Choose "Encode Component" for single parameter values, "Encode Full URL" for complete web links, or "Decode URL" to parse percent-encoded strings back to plain text.
- Paste URL or Parameter: Type or paste your URL into the input panel, or click "Load Sample URL" for a demonstration.
- Inspect Query Parameter Breakdown: View the extracted Query Parameter key-value table showing parsed URL query variables.
- Copy Encoded Result: Instantly copy your percent-encoded URL string with 1 click.
Key Features & Technical Capabilities
- Query Parameter Breakdown Table: Automatically parses complex URLs into a clean key-value parameter table for easy debugging.
- Dual Encoding Engines (`encodeURI` vs `encodeURIComponent`): `encodeURI` preserves structural delimiters (`?`, `&`, `/`, `#`), whereas `encodeURIComponent` encodes all reserved characters for parameter values.
- Full UTF-8 Percent Encoding: Encodes emojis, spaces, and international foreign alphabets into valid percent-encoded hex sequences.
- 100% Client-Side Privacy: API endpoints, query strings, and tracking tokens are processed locally in your browser memory.
Best Practices for Web URL Encoding
- Use `encodeURIComponent` for Query Parameters: Always encode user-submitted values passed inside URL query strings (e.g. `?name=John%20Doe&email=john%40example.com`) to prevent breaking URL structure.
- Encode Spaces as `%20` or `+`: Standard percent-encoding represents spaces as `%20`, while application/x-www-form-urlencoded uses `+`. Modern web servers accept both.
- Preserve Reserved Delimiters in Full URLs: When encoding an entire web link, use `encodeURI()` so protocol scheme slashes (`https://`) and domain separators remain valid.
Frequently Asked Questions (FAQ)
When should I use encodeURIComponent versus encodeURI?Use `encodeURIComponent` when encoding query parameter values (e.g. `?query=value`). Use `encodeURI` when encoding a full URL address without breaking protocol slashes (`https://`).
Why are spaces converted into `%20`?URLs cannot contain literal space characters. In ASCII percent-encoding, space corresponds to decimal value 32, which is represented in hexadecimal as `%20`.
Is my URL data logged on any server?No! URL parsing and percent-encoding happen 100% locally inside your web browser using JavaScript string functions.
How do I decode `%20` and `%26` back into plain text?Select "Decode URL" mode and paste your percent-encoded URL string. The tool will parse `%20` back into spaces and `%26` back into `&` instantly.