Dev
Mock HTTP Header Generator
Manually writing HTTP header sets for test cases is slow — a missing Accept-Language can break localization logic, a wrong Content-Type silently fails parsing. A mock HTTP header generator produces complete, consistent header sets for three client profiles. Three inputs control the output. Count sets how many sets to generate (1–10). Request Type picks the client profile: Browser generates User-Agent, Accept, Accept-Language, Accept-Encoding, Connection, and Cache-Control; Mobile substitutes mobile OS User-Agents and adds X-App-Version and X-Platform; API Client replaces browser headers with Content-Type, Authorization (Bearer token), X-Request-ID, and X-API-Key. Random mixes all three. Output Format switches between raw headers for curl, or a JSON object for fetch() or Axios. Generated Authorization values are randomly assembled strings — they will not authenticate against live APIs.
Read the complete guide — 4 min read
Added April 2026
How to use
- Choose your options above
- Click Generate
- Copy your result
Detailed instructions
- Set the Count field to the number of distinct header sets you need for your test scenario.
- Choose a Request Type from the dropdown — browser, mobile, or API client — to match the traffic you want to simulate.
- Click Generate to produce the header sets, then review each set for the fields relevant to your use case.
- Copy the entire set or individual header lines and paste them into Postman, a curl command, or your test fixture file.
Use Cases
- •Seeding a Postman collection with browser, mobile, and API client header sets to simulate diverse traffic against a staging endpoint
- •Testing Express.js middleware that parses User-Agent strings for device detection before it ships to production
- •Reproducing a client-specific bug where a malformed Accept-Encoding header caused a Flask response to decompress incorrectly
- •Loading realistic header fixtures into k6 or Locust scripts so caching and routing logic sees varied client signatures under load
- •Validating CORS configuration by firing browser-profile requests that include Origin and Referer fields at your API endpoint
Tips
- →Generate browser and API-client sets separately and compare responses — differences often reveal auth or content negotiation bugs.
- →When testing User-Agent parsing, generate at least five sets and include Random type to catch edge cases your parser may not handle.
- →For CI test fixtures, generate a batch of eight sets once and commit them to your repo rather than generating fresh ones each run, ensuring reproducible tests.
- →Combine a generated Authorization header with your actual test credentials to validate that your auth middleware accepts the correct token format.
- →If your server reads Accept-Language for localization, check the generated value and confirm your logic handles the q-factor weighting syntax it includes.
- →Use the mobile request type when testing responsive APIs or endpoints that return different payloads based on detected device type.
FAQ
what HTTP headers does this generator actually include
Browser sets include User-Agent, Accept, Accept-Language, Accept-Encoding, Connection, and Cache-Control. Mobile sets use mobile OS User-Agents and add X-App-Version and X-Platform. API Client sets include User-Agent (an HTTP library string), Accept, Content-Type, Authorization (Bearer), X-Request-ID, and X-API-Key. The exact fields shift by Request Type so values stay internally consistent.
are the authorization tokens in these headers usable against real APIs
No. Generated Authorization values match real formats — Bearer tokens, API keys — but are not tied to any live account. They verify that your parser accepts the correct format and that middleware routes or rejects requests as expected. For tests hitting a real authenticated endpoint, replace the generated token with a valid credential.
what is the difference between the browser, mobile, and API client request types
Browser sets include fields real browsers send automatically — Accept-Language with q-factor weighting, Accept-Encoding, Cache-Control. Mobile sets use mobile OS User-Agents (Android, iOS) and add app-version and platform headers. API Client sets focus on Content-Type and Authorization typical of REST or SDK consumers, omitting browser-only fields.
can I get the headers as a JSON object for use in fetch or Axios
Yes — set Output Format to JSON object and each set is returned as a key-value object you can paste straight into a fetch() headers option or an Axios headers config. Leave it on Raw headers for the newline-separated format that drops into curl, Postman, or a .http file.
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