JSON & API

HTTP Request Header Builder

Create, validate, organize, preview, import, and export HTTP request headers locally in your browser.

Statistics

Live quality signals for the current header set.

Header Editor

Enable, reorder, duplicate, and validate request headers.

Filter

Smart Presets

Insert common request headers with one click.

Import

Load JSON objects, raw header text, or cURL header arguments.

Built-In Examples

Start from common API scenarios.