Text Parsing & Sanitization: Implementing HTML WYSIWYG Editor inside Workflows
August 18, 2026 · The Devs Tools Team
WYSIWYG stands for "what you see is what you get" — an editing paradigm where formatting a document visually (clicking a bold button, indenting a list, inserting a heading) produces the corresponding underlying markup automatically, rather than requiring the author to hand-write tags. In the browser, this is typically built on top of contenteditable regions or a structured document model, where every visual action — selecting text and clicking "bold," pressing Tab inside a list — is translated into a specific HTML element or attribute change under the hood. The core challenge is keeping the visual representation and the raw markup representation in perfect sync: what the user sees rendered on screen must always correspond exactly to the HTML string that gets extracted when they're done.
This dual-representation model is valuable anywhere non-technical users or fast-moving workflows need to produce HTML without writing it directly. A marketer composing an email body, a developer prototyping a component's inner content, or anyone needing to quickly generate clean, structurally valid HTML from formatted text benefits from working visually on one side while getting a copy-ready raw HTML string on the other — no need to hand-write <strong>, <ul><li>, or heading tags, and no risk of malformed markup from manual editing. The two-pane layout, visual composition on the left and live raw HTML output on the right, makes the mapping between formatting action and generated markup transparent as you work.
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The Visual-to-Markup Mapping
Every formatting action corresponds to a specific structural change:
User action → Generated HTML
─────────────────────────────────────────────
Select text, click Bold → <strong>text</strong>
Select text, click Italic → <em>text</em>
Press Tab in a list item → nested <ul><li>...</li></ul>
Insert Heading 2 → <h2>Section Title</h2>
Type a new paragraph → <p>New paragraph</p>
A minimal example of the resulting output for a short composed document:
<h2>Release Notes</h2>
<p>This update includes the following changes:</p>
<ul>
<li><strong>Fixed</strong> a rendering bug in the sidebar</li>
<li><em>Improved</em> load time on the dashboard</li>
</ul>
Why the Mapping Isn't Always Trivial
- Nested formatting: Applying bold inside an already-italicized selection needs to produce properly nested tags (
<em><strong>text</strong></em>) rather than overlapping, invalid markup. - Paste handling: Content pasted from Word documents or other web pages often carries bloated, inconsistent markup (inline styles, redundant spans) that a clean editor should normalize rather than preserve verbatim.
- List structure: Indent/outdent actions must produce correctly nested
<ul>/<ol>elements, not just visual indentation via CSS. - Empty elements: Deleting all text inside a formatted element should remove the now-empty tag rather than leaving dangling markup behind.
Practical Uses
- Email and newsletter bodies: Composing formatted content without writing HTML by hand.
- CMS content blocks: Generating markup for systems that expect raw HTML input fields.
- Component prototyping: Quickly producing sample HTML content to drop into a component during development.
- Documentation snippets: Formatting a block of text visually and grabbing the resulting HTML for a README or wiki page.
Conclusion
A WYSIWYG editor's real job is maintaining a reliable translation layer between visual formatting actions and clean, valid HTML markup — handling nested styles, list structure, and pasted content without producing broken output. Doing that translation entirely client-side means whatever content you're composing, however sensitive or unpublished, stays in your browser until you're ready to copy it out.