About

In the landscape of modern web development, the bridge between raw text and semantic HTML is often fraught with inefficiency. Content creators and developers frequently rely on bloated WYSIWYG editors that generate non-semantic "spaghetti code," harming SEO and accessibility. This tool offers a deterministic, client-side environment for transforming Markdown syntax into production-ready HTML markup.

Unlike basic converters, this architecture prioritizes the Write-Render-Preview loop. It solves the context-switching problem via an algorithmic synchronized scrolling engine and provides immediate visual verification of document structure. By decoupling the content (Markdown) from the presentation (CSS), it empowers developers to prototype documentation, blog posts, and technical specs with absolute precision before deployment.

Formulas

The core challenge in a dual-pane editor is maintaining contextual alignment between the raw source (varying line heights) and the rendered output (images, headers, padding). We utilize a Proportional Mapping Algorithm to synchronize the viewports.

Let H_src be the total scrollable height of the Markdown editor and H_dest be the height of the HTML preview. If the user scrolls to position y_src, the target position y_dest is derived as:

y_dest = y_srcH_src − V_src × (H_dest − V_dest)

Where V represents the viewport height (client height). This linear interpolation ensures that the relative percentage of scroll remains constant across both DOM elements.

Reference Data

Element	Syntax Pattern	HTML Structure	Semantic Role
Primary Heading	`# Header`	`<h1>Header</h1>`	Page Title (SEO H1)
Secondary Heading	`## Header`	`<h2>Header</h2>`	Section Divider
Emphasis (Strong)	`text`	`<strong>text</strong>`	Urgency/Importance
Emphasis (Italic)	`text`	`<em>text</em>`	Stress/Intonation
Unordered List	`- Item`	`<ul><li>Item</li></ul>`	Non-sequential collection
Ordered List	`1. Item`	`<ol><li>Item</li></ol>`	Sequential steps
Task List (GFM)	`- [x] Item`	`<input type="checkbox" checked>`	Progress tracking
Blockquote	`> Text`	`<blockquote><p>Text</p></blockquote>`	Citation/Reference
Inline Code	`const x`	`<code>const x</code>`	Technical terminology
Fenced Code Block	```js code ```	`<pre><code class="language-js">`	Algorithmic content
Hyperlink	`[Label](URL)`	`<a href="URL">Label</a>`	Navigation
Image	`![Alt](URL)`	`<img src="URL" alt="Alt">`	Visual media
Table Row	`\| A \| B \|`	`<tr><td>A</td><td>B</td></tr>`	Tabular data
Horizontal Rule	`---`	`<hr>`	Thematic break

Frequently Asked Questions

Yes. The parser includes support for GFM-specific features such as Task Lists (`- [ ]`), Tables (`| col | col |`), and Strikethrough (`~~text~~`), extending the standard CommonMark specification.

No. The architecture is strictly client-side. The regex parsing engine runs entirely within your browser's JavaScript runtime. Your intellectual property never leaves your local machine, ensuring maximum privacy for sensitive documentation.

Absolutely. The "Copy HTML" function generates sanitized, clean markup that is compatible with any modern CMS. It strips unnecessary wrapper classes, leaving only the semantic tags (h1, p, ul, etc.) that inherit your site's native styling.

The tool injects a scoped `` block into the preview shadow DOM. You can select from built-in themes (like "GitHub Light" or 'Swiss Minimal') or paste your own CSS to simulate exactly how the content will render on your specific production environment.

Markdown and HTML differ fundamentally in vertical rhythm. An image in HTML might take 400px height, while its Markdown reference takes 1 line. The Proportional Mapping Algorithm approximates the position based on percentage, which is the industry standard for performance-critical editors.