Paste any HTML — elements with data-* attributes will be extracted
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Paste HTML and click Extract// extract all data-* attributes from html instantly
Extract and list all custom data-* attributes and their values from any HTML snippet. Instantly parse data attributes for debugging, auditing, and documentation.
Ready to extract
Paste HTML and click ExtractDrop any HTML snippet, component, or full page markup into the input box.
Choose grouping (none, by attribute name, by element tag) and toggle context display.
Click Extract, filter results, then copy or export as JSON / CSV for documentation.
The HTML Data Attribute Extractor scans any HTML markup and pulls out every data-* attribute along with its value, parent element, id, and class context. It runs entirely in your browser — no server, no uploads, no data leaves your machine.
HTML data attributes are custom attributes prefixed with data- that let you store extra information on HTML elements. They were standardized in HTML5 and are accessible in JavaScript via element.dataset. For example, data-user-id="42" stores a user ID directly on a DOM element.
No. All extraction runs entirely in your browser using JavaScript's DOMParser. Nothing is uploaded or transmitted. Your code stays private on your machine.
Yes. The tool uses the browser's native HTML parser which is highly fault-tolerant — the same parser used to render web pages. It will handle unclosed tags, missing quotes, and other common HTML errors.
The JSON export includes each extracted attribute as an object with fields: attribute (name), value, element (tag name), id, and class. Perfect for feeding into documentation tools or test fixtures.
None shows all attributes in document order. "Group by attribute" clusters results by attribute name so you can see all data-action values at once. "Group by element" organizes results by HTML tag type (all div attributes together, etc.).
Yes — paste as much HTML as you need. The extractor handles full pages, component libraries, template files, and small snippets equally well. Very large inputs may take a moment to parse.
An HTML Data Attribute Extractor is a developer tool that scans HTML markup and collects every data-* attribute it finds, along with the attribute's value and the element it belongs to. Instead of manually reading through hundreds or thousands of lines of HTML to find data bindings, this tool gives you an instant structured list you can filter, group, copy, and export.
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Introduced with HTML5, data-* attributes are a standardized way to embed custom data into HTML elements without resorting to non-standard attributes, hidden inputs, or JavaScript globals. The specification is simple: any attribute whose name begins with data- followed by at least one character is a valid data attribute.
The data is accessible in JavaScript through the HTMLElement.dataset API, which automatically converts kebab-case attribute names to camelCase property names. For example, data-user-id becomes element.dataset.userId.
Data attributes appear in nearly every modern web application. You'll find them used for:
data-event="click", data-category="navigation"data-toggle="modal", data-target="#dialog"data-theme="dark", data-size="large"data-endpoint="/api/v2/users", data-method="POST"data-state="active", data-expanded="false"data-tooltip="Click to submit"data-testid="submit-button", data-cy="login-form"There are several practical reasons a developer needs to see all data attributes in a document at once:
Refactoring: Before renaming a data attribute across a codebase, you need to know every element that currently uses it and what values it carries. An extractor gives you that inventory instantly.
Auditing analytics: Marketing and analytics teams rely on data- attributes for event tracking. Extracting them from landing pages lets you verify that every tracked element is properly tagged before a campaign goes live.
Documentation: Component libraries often communicate behavior through data attributes. Extracting them from a component's HTML gives you the raw material for API documentation.
Debugging: When a JavaScript library stops responding to data bindings, the first step is confirming the attributes exist with the expected names and values. An extractor eliminates the guesswork.
Test fixture creation: End-to-end testing frameworks like Playwright and Cypress commonly use data-testid attributes as selectors. Extracting all test IDs from a page gives QA teams the full selector inventory.
This tool uses the browser's native DOMParser API to parse your HTML into a real DOM tree — the same engine that renders web pages. It then walks every element in that tree and inspects its attributes for the data- prefix. Because it uses a real parser, it correctly handles malformed HTML, deeply nested structures, self-closing tags, and encoded characters.
Results are returned with the attribute name, its value, the element's tag name, its id attribute (if present), and its class attribute (if present). This context makes it easy to locate the element in your source without needing line numbers.
Raw lists of attributes can be hard to read in large projects. The tool offers three display modes:
data-action appear together, letting you compare values across elements instantly.<button> attributes together, useful when auditing a specific component type.The live filter lets you narrow results by attribute name or value. Typing "action" immediately hides everything that doesn't match, making it trivial to find a specific attribute in a large result set.
Two export formats are available. JSON export produces a structured array of objects, each with attribute, value, element, id, and class fields. This format is ideal for feeding into documentation generators, test utilities, or custom scripts. CSV export produces a spreadsheet-compatible file with the same columns, useful for sharing with non-technical stakeholders or loading into analytics tools.
It's worth distinguishing data attributes from other custom attributes. ARIA attributes (aria-label, aria-expanded) serve accessibility purposes and are not data attributes. Framework-specific attributes like Vue's v-bind or Angular's [ngClass] are directives, not data attributes. This extractor focuses specifically on the HTML5 data-* namespace, which is the portable, specification-compliant way to embed custom metadata in HTML.