URL Query String Decoder
Parse and decode URL query strings into readable key-value pairs. 100% client-side — nothing leaves your browser.
192 chars
Base URL:https://codekeet.com/search
Fragment:#results
10
Parameters
9
Unique keys
4
Encoded values
156
Query chars
🔍 Decoded parameters
| Key | Value | Actions | |
|---|---|---|---|
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 | |||
| 8 | |||
| 9 | |||
| 10 |
🔗 Rebuilt query string
q=hello%20world&category=dev%20tools&page=2&sort=relevance&tag=web&tag=javascript&utm_source=newsletter&utm_medium=email&user%5Bname%5D=Alice&user%5Bage%5D=30
📋 JSON representation
{
"q": "hello world",
"category": "dev tools",
"page": "2",
"sort": "relevance",
"tag": [
"web",
"javascript"
],
"utm_source": "newsletter",
"utm_medium": "email",
"user[name]": "Alice",
"user[age]": "30"
}Duplicate keys become arrays. Bracket notation (user[name]) is kept as-is.
🔒 100% private: All parsing happens in your browser. Your URLs (including any tokens) never leave your device.
About URL Query String Decoder
Query strings are the part of a URL after the "?" — a series of key=value pairs separated by "&". They carry search terms, pagination, filters, tracking parameters (UTM), API arguments, and authentication tokens. Raw query strings are hard to read: %20 means space, %26 means literal &, %3D means literal =, and + often means space (form data convention). Long query strings from real APIs can be hundreds of characters of encoded gibberish. This tool parses a query string into a clean table — each key and value decoded and displayed side by side. It handles URL encoding, plus signs, duplicate keys, and bracket notation (a[b]=c), and shows both raw and decoded forms so nothing is lost.
How It Works
- Paste a full URL or just the query string (?a=1&b=hello%20world).
- See each parameter decoded in a table.
- Toggle between raw (encoded) and decoded views.
- Copy individual values, export as JSON, or use the rebuilt query string.
✨ Key Features
- ✓Parse query string from a full URL or a fragment
- ✓Decode URL encoding (%20, %26, %3D, %2F, etc.)
- ✓Handle "+" as space (application/x-www-form-urlencoded)
- ✓Support duplicate keys (?tag=a&tag=b)
- ✓Detect bracket notation (a[b]=c, a[]=1)
- ✓Show both raw and decoded values
- ✓Rebuild the query string from the parsed parameters
- ✓Export as JSON object
- ✓Copy individual keys or values
- ✓Show parameter count and total length
- ✓100% client-side — no data sent to any server
🎯 Common Use Cases
- →Debugging API requests with complex query strings
- →Decoding UTM tracking parameters on marketing links
- →Reading OAuth callback URLs with encoded tokens
- →Parsing search/filter URLs from a web app
- →Understanding duplicate keys and bracket notation
- →Extracting specific parameters from long URLs
- →Converting a query string to a JSON object
- →Analyzing URLs from server logs
💡 Advanced Tips & Pro Insights
- ▸URL encoding (%XX): special characters are encoded as % followed by two hex digits. Space = %20, & = %26, = = %3D, / = %2F, ? = %3F, # = %23, + = %2B.
- ▸In application/x-www-form-urlencoded (typical HTML forms and query strings), "+" also represents a space. This tool decodes both %20 and + as space.
- ▸Duplicate keys are valid (?tag=a&tag=b) and common. This tool preserves both. Most APIs treat them as an array.
- ▸Bracket notation (?user[name]=Alice&user[age]=30) is a PHP/Rails convention for nested objects. This tool detects and displays it but keeps the raw key.
- ▸The "#" fragment is not part of the query string — it is client-side only. This tool stops at "#".
Frequently Asked Questions
Is this query string decoder free?▾
Yes, this URL query string decoder is completely free with no signup, email, or usage limits.
Is my data safe?▾
Yes, 100% safe. All parsing and decoding happens in your browser. Your URLs and tokens are never uploaded to any server.
What is URL encoding?▾
URL encoding (percent-encoding) converts special characters into %XX format so they can be safely included in a URL. Space becomes %20, & becomes %26, = becomes %3D. Non-ASCII characters (like é or नमस्ते) are encoded as UTF-8 byte sequences.
Why does + sometimes mean space?▾
In application/x-www-form-urlencoded (used by HTML forms and most query strings), "+" is shorthand for space. This tool decodes both %20 and + as space. If you need a literal +, it should be encoded as %2B.
How are duplicate keys handled?▾
Duplicate keys are valid and common (?tag=a&tag=b). This tool lists every occurrence separately, so nothing is lost. When exporting to JSON, they become an array.
What is bracket notation?▾
Bracket notation (?user[name]=Alice) is a convention used by PHP, Rails, and some frameworks to represent nested objects. This tool keeps the raw key "user[name]" and can optionally show the nested structure.
Can I decode a full URL or just the query part?▾
Both. Paste "https://example.com/path?a=1&b=2" or just "?a=1&b=2" — the tool extracts the query string and parses it. If there is no "?", it treats the entire input as a query string.
What about the #fragment?▾
The fragment (after "#") is not sent to the server and is not part of the query string. This tool stops parsing at "#".