When should I add charset to Content-Type?
Add charset when you serve text payloads that must render predictably, such as JSON, HTML, XML, CSV, or plain text.
Content-Type Generator (MIME Header Builder)
Generate valid Content-Type headers with charset and boundary
API & HTTP
π 100% client-side β your data never leaves this pagePage mode
Content-Type Builder
Quick CTA
Fill type and subtype first to generate a Content-Type header; boundary, extra params, and scenario comparisons stay in Deep.
Output
Generated header appears here
100% client-side
Page reading mode
Quick keeps the summary, direct answers, and next steps so you can validate fit and get a result faster.
About this tool
Content-Type Generator builds copy-ready HTTP Content-Type values for API requests and responses. Choose media type and subtype, then add optional charset, boundary, and custom parameters to generate normalized output immediately. It is useful for Postman and cURL testing, backend integration, gateway policy checks, and API documentation. The tool helps prevent common mistakes such as missing charset, incorrect multipart boundary, or malformed parameter syntax. You can copy pure Content-Type values or full header lines directly. All generation runs in your browser.
Direct Answers
When do I need a multipart boundary?
Use a boundary for multipart/form-data requests, especially file uploads, and make sure it matches the body separators exactly.
Suggested Workflow
API Debugging Checklist: From Broken Response to Root Cause
A practical debugging flow for API payload errors, auth failures, and malformed responses.
Why 415 Unsupported Media Type Happens (and How to Fix It Fast)
A practical problem page for debugging 415 errors with exact header checks and copy-ready fixes.