Accept Header Generator
Generate Accept, Accept-Language, and Accept-Encoding HTTP headers for API client configuration. Choose from a rich library of MIME types, languages, and encoding options with proper quality values - then copy the output as raw HTTP headers, JavaScript fetch() options, or cURL arguments. All processing is local, no data uploaded.
Generate Accept, Accept-Language, and Accept-Encoding headers for HTTP client configuration. Select content types, languages, and encodings with quality values - then copy as raw headers, fetch() options, or cURL arguments.
Available types (26)
Web & API
Images
Audio & Video
Documents & Data
Available languages (35)
Available encodings (2)
Accept: application/json, text/html;q=0.8, application/xml;q=0.5 Accept-Language: en-US, en;q=0.5 Accept-Encoding: gzip, br;q=0.9, deflate;q=0.5
Why Use Our Accept Header Generator?
Multi-Header Generation
Generate Accept, Accept-Language, and Accept-Encoding headers simultaneously from a single interface. Each header is built from your selections with proper formatting, quality values, and priority ordering - ready to paste into any HTTP client.
Rich Content Type Library
Choose from 35+ pre-configured MIME types organized by category - Web & API, Images, Audio & Video, and Documents & Data. Also includes 35+ language tags and 5 encoding options with descriptions of when to use each.
Multiple Export Formats
Copy generated headers as raw HTTP header values, JavaScript fetch() options, or cURL arguments. Each format is tailored for its use case - raw for manual configuration, fetch() for browser code, and cURL for terminal debugging.
Pre-built Presets
Start from 4 ready-to-use presets covering common scenarios: REST API Client, Web Browser, Image Downloader, and Multi-language API Client. Each preset sets up the appropriate content types, languages, and encodings with correct quality values.
Common Use Cases for Accept Header Generator
API Client Configuration
Configure proper Accept headers for REST, GraphQL, and gRPC API clients. Set the correct content type preferences and quality values to ensure your API client requests the right response format from servers that support multiple content types.
cURL & HTTPie Command Building
Generate the exact -H flags for cURL or HTTPie commands when debugging APIs. Copy the generated headers directly into your terminal commands without manually typing header syntax - perfect for quick API testing and troubleshooting.
HTTP Client Debugging
When an API returns unexpected content types, use the generator to build precise Accept headers and test different combinations. Isolate whether content negotiation issues are caused by missing or incorrectly formatted Accept headers.
JavaScript / TypeScript Fetch Setup
Generate fetch() options with properly formatted Accept headers for use in browser or Node.js applications. Copy the generated headers object directly into your code - no manual header formatting or quality value calculation needed.
API Integration Testing
Use the generated Accept headers to write comprehensive API integration tests. Test content negotiation by generating different Accept header combinations and verifying that your API responds with the expected content types and formats.
Multi-Region & i18n Configuration
Configure Accept-Language headers for multi-language API clients and internationalized applications. Properly prioritize language preferences with quality values to ensure users receive content in their preferred language when available.
Understanding Accept Headers
What Are Accept Headers?
Accept headers are HTTP request headers that tell the server what content types, languages, and encodings the client can understand. The Accept header specifies MIME types the client prefers (e.g., JSON over XML). Accept-Language indicates the preferred natural language. Accept-Encodingtells the server which compression algorithms the client supports. Together, these headers enable HTTP content negotiation - the process where servers select the best representation of a resource based on the client's capabilities and preferences.
How Quality Values (q) Work
Quality values, ranging from 0 to 1, express relative preference using the ;q= parameter. A value of 1 is the highest preference (default if omitted), while 0 means the client does not want that option at all. For example, Accept: application/json;q=1, text/html;q=0.5 tells the server the client strongly prefers JSON but will accept HTML as a fallback. Servers use these values to determine the best response format when multiple options are available.
How Our Accept Header Generator Works
- Select: Choose the content types, languages, and encodings you want from the preset libraries. Each entry can be individually enabled, disabled, or removed.
- Configure: Adjust quality values and reorder entries to set your preferences. The generated headers update in real-time as you make changes.
- Copy: Export the generated headers in your preferred format - raw HTTP header values, JavaScript fetch() options, or cURL command arguments.
Privacy & Security
All header generation happens entirely in your browser using client-side JavaScript. No data is uploaded to any server, no cookies are used, and no tracking is involved. The tool requires no signup, no API keys, and works completely offline after the initial page load. You can generate headers for any application - including sensitive or internal APIs - without any privacy concerns.
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Frequently Asked Questions About Accept Header Generator
Accept headers are HTTP request headers that enable content negotiation between clients and servers. The Accept header tells the server which MIME types the client can process, Accept-Language specifies preferred human languages, and Accept-Encoding indicates supported compression algorithms. Servers use these headers to choose the best representation of a resource to send back to the client.
Content negotiation is the mechanism defined in HTTP that allows clients and servers to agree on the best representation of a resource. When a server receives a request with Accept headers, it examines the client's preferences and selects the most appropriate response format. For example, an API might serve JSON to clients that prefer it (Accept: application/json) and XML to clients that request it (Accept: application/xml).
Quality values range from 0 to 1 and indicate relative preference, where 1 is the highest preference. For example, "Accept: application/json;q=1, text/html;q=0.5" means the client strongly prefers JSON but will accept HTML as a fallback. If no quality value is specified, it defaults to 1. A value of 0 means the client does not want that option at all.
Identity encoding means the client can accept uncompressed content - it tells the server not to apply any compression. If you omit Accept-Encoding entirely, the server may still send compressed content based on its own configuration. Including "identity;q=0" explicitly tells the server the client does not want compressed responses, which can be useful for debugging or when working with legacy systems.
The most common Accept header for REST APIs is "Accept: application/json" since JSON is the standard data interchange format for modern web APIs. Many APIs also support "Accept: application/xml" for legacy compatibility. For GraphQL APIs, "Accept: application/graphql+json" is commonly used. Some APIs use custom media types like "Accept: application/vnd.github.v3+json" for versioned API responses.
Yes, Accept headers support wildcard patterns. Use "*/*" to accept any content type, "image/*" to accept any image type, or "text/*" to accept any text-based type. Wildcards are typically given lower quality values (e.g., ";q=0.5") to indicate they are fallback options. The browser's default Accept header often ends with "*/*;q=0.8" to accept any content as a last resort.
List languages in order of preference with optional quality values. For example: "Accept-Language: fr-FR;q=1, fr;q=0.9, en-US;q=0.8, en;q=0.5". This tells the server you prefer French (France), then any French, then English (US), then any English. The Accept Header Generator automatically sorts entries by quality value so the highest-priority language appears first.
Including Accept-Encoding in your requests tells the server which compression algorithms your client supports. This can significantly reduce bandwidth usage - for example, Brotli (br) can compress HTML by 20-30% more than gzip. Most browsers include Accept-Encoding automatically, but when making programmatic HTTP requests (cURL, fetch, API clients), you should explicitly set it to benefit from compression.
Yes, the Accept Header Generator is completely free to use. All header generation happens locally in your browser - no data is uploaded to any server, no API keys are required, and no signup is needed. You can generate as many header combinations as you want with complete privacy.