HTML to Avro Converter

About HTML to Avro Converter

Convert HTML pages into Apache Avro schemas and JSON data, ready for use in data pipelines, Kafka topics, Hadoop/Spark jobs, or schema registries. The tool analyzes the HTML structure and extracts key fields such as title, headings, paragraphs, links, images, lists, and metadata into a strongly typed Avro record.

Key Features

• Automatic Avro schema generation: Build an Avro record with nested records, arrays, and enums based on common HTML elements.
• Structured data extraction: Collect headings, paragraphs, links, images, lists, and meta tags into a single JSON object.
• Flexible output: Export schema only (as .avsc) or combine schema + extracted data in one JSON payload.
• Custom schema name: Set your own Avro record name to match existing conventions.
• Metadata-aware: Include charset, description, and keywords from HTML <meta> tags.
• Ready for pipelines: Designed with Kafka, schema registries, and big data processing tools in mind.

How to Convert HTML to Avro

1. Paste or upload HTML: Use the input panel to paste HTML or upload an .html file.
2. Choose output: Decide whether to include extracted data or generate the schema only.
3. Set schema name: Optionally provide a custom Avro record name (e.g., ArticleDocument).
4. Review JSON output: Inspect the generated Avro schema and/or data in the output area.
5. Copy or download: Copy the JSON or download it for use in your data pipeline.

Examples

Example 1: Blog article HTML

A blog page with a <title>, headings, paragraphs, links, and images will be converted into an Avro record where:

• title holds the document title.
• headings is an array of { level, text } records.
• paragraphs is an array of strings.
• links contains { href, text } for each hyperlink.
• images stores { src, alt } for each image.

Example 2: Documentation page

Technical docs with lists and sections are mapped to Avro where lists contains list type (ordered/ unordered) and items, allowing downstream systems to analyze navigation or content structure.

When to Use HTML to Avro

• Web content ingestion: Normalize HTML pages into Avro for Kafka or event streaming pipelines.
• Search & analytics: Extract text content and metadata to feed search indexes or analytics engines.
• Archiving: Store web snapshots with a stable, versioned Avro schema.
• Schema-first development: Derive initial Avro schemas directly from real HTML content.

About Apache Avro

Apache Avro is a compact, fast, binary data serialization format with rich schema support. It is widely used with Apache Kafka, Hadoop, and other big data technologies for:

• Defining versioned, evolvable schemas for your data.
• Efficient binary encoding and decoding.
• Interoperability across languages and platforms.

FAQ

Does this tool output binary .avro files?

No. The converter generates Avro schemas and data in JSON form, which you can feed into your own tools or pipelines that produce binary .avro files.

Can I add or remove fields from the schema?

The generated schema is a good starting point. You can edit the JSON to add custom fields or remove ones you do not need before registering it in your schema registry.

How are null or missing values handled?

Fields like title, description, and keywords use Avro unions with ["null", "string"] so missing values are represented safely as null.

Is my HTML uploaded to a server?

No. All HTML to Avro conversion happens locally in your browser. Nothing is sent to external services, which is important when processing internal documentation or private web content.

Privacy & Security

All parsing and schema generation are done client-side. Your HTML, generated Avro schemas, and data are never logged or transmitted, making this tool safe for confidential data pipelines.