HTML to JSX Converter

Browsers are forgiving when they read HTML. They may close a missing tag, rearrange misplaced elements, or accept an attribute form that a JavaScript compiler will reject. JSX sits on the stricter side of that boundary: it resembles HTML, but it becomes JavaScript syntax and must describe one valid element tree.

That distinction matters when markup moves from a static prototype, content system, email template, or SVG editor into a React codebase. The visible layout may survive a copy-and-paste while the source still contains HTML-only names, string-based event code, CSS declaration text, comments, or sibling roots that need different JSX forms.

Mechanical conversion can rename attributes, form fragments, self-close empty elements, and reshape inline styles. It cannot decide which component should own state, whether an event belongs in the markup, or whether the resulting accessibility relationships still make sense. A syntactically tidy result is a migration draft, not a substitute for a build, lint, behavior, and accessibility review.

Source scope also changes meaning. HTML parsing follows the browser's repair rules, while an SVG root is parsed as stricter XML. A full document includes the html, head, and body tree; a normal component usually needs only the meaningful body nodes. Choose the scope before judging the output.

How to Use This Tool:

Decide whether the source is an HTML fragment, a complete document, or an SVG root before choosing the output wrapper.

1. Paste the markup or load one HTML, HTM, SVG, or text file under 1 MiB into HTML source.
2. Select Source scope. Use Auto for ordinary fragments, Full document when document-level tags are intentional, or SVG root for strict SVG/XML parsing.
3. Choose a React component, fragment, or raw JSX under Output shape. For a component, provide a valid descriptive component name and choose its export form.
4. Set the inline-style and event policies. Style objects are the normal React form; handler stubs still require manual review, and omission removes those attributes from the result.
5. Read Attribute migration and Conversion checks before copying the JSX. Correct the source if SVG parsing fails or the review notes identify raw-text elements, event strings, or a dropped doctype.

Interpreting Results:

The generated JSX is ready for code review when the conversion status is clear and the migration rows explain every meaningful attribute change. A small byte count or a zero-warning badge does not prove that the component behaves correctly.

• Inspect every converted event prop and replace copied inline code with project-owned functions.
• Check style objects for custom properties, vendor-prefixed names, and values that should remain strings.
• Compare the rendered result with the source after the JSX has passed the target project's compiler and lint rules.
• Recheck labels, ARIA relationships, keyboard behavior, and any browser-repaired structure.

Technical Details:

HTML-to-JSX conversion begins with a parsed element tree rather than a text-only search and replace. That preserves nesting and distinguishes elements, text, comments, and attributes. HTML mode uses browser HTML parsing, which may repair malformed markup; SVG mode uses XML parsing and reports malformed XML instead of silently repairing it.

Transformation Core

The central path is parse, walk, map, format, and wrap. Each stage changes a different part of the source and leaves a review record for attributes.

1. Normalize line endings and parse either HTML or an SVG/XML root.
2. Walk element, text, and comment nodes in document order.
3. Map React DOM and SVG attribute names while preserving data-* and aria-*.
4. Apply the selected policies for styles, events, comments, booleans, and whitespace.
5. Format one component, one fragment, or raw JSX with two- or four-space indentation.

Policy choices can preserve, transform, or omit source material. They are intentionally visible because two valid conversions may make different tradeoffs.

Worked Transformation Path

<label for="email"> is parsed as a label element with a for attribute. Attribute mapping changes that name to htmlFor, the text child is escaped for JSX, and the closing tag is retained. The result is <label htmlFor="email">...</label>. A nearby disabled input becomes either disabled={true} or the shorthand disabled, depending on the boolean policy.

Bounds and Failure Rules

• Source must contain at least one converted element and remain at or below 1 MiB.
• Component names are normalized into PascalCase and must not be blank.
• SVG/XML parse errors stop conversion; HTML parse repairs may instead change the tree and require visual comparison.
• Raw text in script, style, textarea, and pre is emitted as text and receives a review warning.
• A doctype is not emitted inside an ordinary fragment or component.

Privacy and Review Notes:

The pasted or loaded markup is parsed and formatted in the current browser; it is not sent to a conversion service. That protects source privacy during conversion, but copied markup can still contain secrets, tracking URLs, unsafe inline JavaScript, or sensitive text.

• Remove credentials, tokens, personal data, and private endpoints before committing generated code.
• Treat event-handler stubs as untrusted copied code until a developer has rewritten and tested them.
• Run the result through the destination project's compiler, linter, tests, and accessibility checks.

FAQ:

References:

• Writing Markup with JSX, React.
• Common components, React.
• HTML Standard: Common microsyntaxes, WHATWG.