URL Encoder for API Integration
Properly encode query parameters, path segments, and form data for REST API requests. Prevent broken requests caused by unescaped special characters.
API developers and backend engineers regularly construct URLs with dynamic query parameters that may contain special characters, Unicode text, or reserved URL characters. Proper percent-encoding ensures that API requests are correctly parsed by servers, proxies, and load balancers without data corruption or security issues.
Encoding for Different API Styles
REST APIs use URL query parameters and path segments, while GraphQL APIs often pass queries as URL-encoded body parameters. OAuth flows require precise encoding of redirect URIs and scope parameters. Each style has specific encoding requirements, and getting them wrong can cause authentication failures, data loss, or security vulnerabilities. This tool handles all these scenarios correctly.
Debugging Encoded API Requests
When an API returns a 400 Bad Request error, the cause is often an improperly encoded parameter. Copy the URL from your HTTP client (Postman, curl, fetch), paste it into the decoder mode to see the actual values being sent, and compare them against the API documentation. This two-step encode-decode workflow catches encoding bugs quickly.
Frequently Asked Questions
Only encode the values of individual query parameters, not the structural characters (?, &, =). Encoding the full URL would break its structure. This tool has a 'Parameter Mode' that encodes only values while preserving URL structure.
Common conventions include repeated keys (color=red&color=blue), bracket notation (color[]=red&color[]=blue), and comma-separated values (color=red,blue). This tool supports all three formats and encodes the values correctly for each.