Inspect the HTTP request headers your browser sends. User-Agent, Accept, and more.
The Request Header Inspector shows the headers that your browser sends with each request—User-Agent, Accept, Accept-Language, and others. Developers use it to debug "wrong content type" or "unsupported format" when the server sees different headers than expected, to copy User-Agent for scripting, or to verify CORS or security headers. Often implemented by sending a request to an echo endpoint that returns the received headers.
The Request Header Inspector shows the headers that your browser sends with each request—User-Agent, Accept, Accept-Language, and others. Developers use it to debug "wrong content type" or "unsupported format" when the server sees different headers than expected, to copy User-Agent for scripting, or to verify CORS or security headers. Often implemented by sending a request to an echo endpoint that returns the received headers. The tool runs entirely in your browser — your data stays on your device and is never transmitted to any server, making it safe for production data and sensitive credentials. Common search terms like request headers, inspect headers, browser headers all lead to this tool because it addresses the specific need for browser-based inspection in the HTTP ecosystem. The HTTP ecosystem includes related tools for formatting, validation, conversion, and more. Each tool handles a specific operation, and Request Header Inspector focuses specifically on inspection — doing one thing well rather than trying to be a general-purpose Swiss Army knife.
Using Request Header Inspector takes just a few seconds — there is no signup, no download, and no configuration required. 1. Enter the data you want to inspect into the input area. 2. The tool analyzes the input and displays detailed information about its structure and contents. 3. Review the metadata, components, and any issues detected by the inspection. 4. Expand sections for deeper analysis of specific parts. 5. Use the findings to debug issues, verify configurations, or understand unfamiliar data formats. All processing happens in your browser, so your data never leaves your device. The tool works on any modern browser (Chrome, Firefox, Safari, Edge) on desktop and mobile.
Developers across all experience levels use request header inspector for quick inspection tasks that would otherwise require writing a one-off script or installing a cli tool. Technical writers and documentation authors use request header inspector to prepare accurate http examples for tutorials, api docs, and developer guides.
Reach for Request Header Inspector when you need to request headers; when you need to inspect headers; when you need to browser headers; when you need to user agent. It eliminates the overhead of writing throwaway scripts or installing CLI tools for quick inspection tasks. Developers who work with HTTP data daily keep this tool bookmarked for instant access. The immediate feedback loop — paste data, see results, copy output — fits naturally into debugging sessions, code reviews, and rapid prototyping workflows where context-switching to a terminal or writing utility code would break your concentration.
To get the most out of Request Header Inspector, it helps to understand how inspection works at a technical level. When working with request headers, keep these details in mind. Modern browsers provide powerful built-in APIs for HTTP processing. These native implementations are optimized in C++ within the JavaScript engine, making browser-based tools fast enough for most real-world inputs. Request Header Inspector processes input entirely in the browser using JavaScript. The browser's sandboxed environment ensures that your data remains on your device and is never sent to any external server. Error handling in Request Header Inspector provides detailed feedback: the type of error, the position in the input where it occurred, and a suggestion for how to fix it. This makes troubleshooting faster than reading generic error messages. The tool handles various input sizes, from small snippets to large documents. For very large inputs (over 10 MB), processing time increases proportionally, but the tool remains responsive thanks to efficient algorithms.
Avoid these common issues when using Request Header Inspector: Character encoding matters: if your input contains non-ASCII characters (accented letters, emoji, CJK characters), make sure the encoding is consistent. UTF-8 is the standard for web content. Ensure your input is in the correct format before using Request Header Inspector. The tool expects valid HTTP input — submitting data in the wrong format produces confusing errors. When searching for 'request headers', make sure you are using the right tool variant. Different HTTP operations (formatting, validation, conversion) solve different problems — using the wrong tool leads to unexpected results. Copy-pasting from word processors or rich text editors may introduce invisible characters (zero-width spaces, smart quotes, non-breaking spaces) that cause parsing failures. Use a plain text editor to prepare input.
Using Request Header Inspector in your browser instead of a local CLI tool or library has distinct advantages for inspection tasks. Privacy is the primary benefit: since Request Header Inspector processes everything client-side using JavaScript, sensitive data like API keys, authentication tokens, production database exports, and internal configuration values never leave your machine. There is no server upload, no logging, and no third-party data processing. For inspection tasks, the visual interface is essential. Color-coded highlights, expandable tree views, and side-by-side layouts provide information density that terminal output cannot match. You can click, scroll, and interact with the results rather than piping text through pagers. Whether you found Request Header Inspector by searching for request headers or inspect headers, the browser-based approach means you can start using it immediately — no signup, no API key, no rate limits, and no usage tracking.
DevTools shows the request for a specific resource; the inspector may hit an echo URL. Both are valid; use the one that matches your scenario.
This tool usually shows your real headers. To send custom headers, use the Request Builder.
It tells the server which languages the client prefers; used for content negotiation and localization.
If the echo URL is same-site, cookies are sent automatically; the inspector shows Cookie if present.
Headers may include X-Forwarded-For or similar if behind a proxy; the echo server may log IP for the response.