Online Avro Validator

Purpose and operation: The Online Avro Validator parses Avro schemas and input data, validating structural correctness and type conformance. It supports complex types such as records, arrays, maps, and unions, including nullable fields and logical types (dates, timestamps, decimals). The tool can operate in three modes: schema-only validation to check syntax, data validation to verify data against a given schema, and compatibility checks to assess writer/reader evolution. It reports detailed errors with field paths, expected versus actual types, and suggestions for remediation, enabling developers to fix issues before ingestion or serialization. By focusing on schema and data correctness, teams reduce runtime failures in streaming pipelines, batch ETL jobs, and storage layers.

How it works conceptually: Users supply a JSON Avro schema and one or more JSON records. The validator parses the JSON, applies Avro's type system recursively, and flags mismatches such as missing required fields, type mismatches, or improper union resolution. When in compatibility mode, it applies writer/reader rules to determine if a new schema can safely evolve from a previous one. It is data-centric: it does not serialize to binary or execute data processing; it only ensures that payloads conform to the declared schema.

Use cases include schema design validation, data onboarding, migration assessment, and pre-ingestion checks for streaming services. The tool provides structured error objects that can be consumed by CI pipelines or metadata registries, and it can export results for audits. Unique value lies in clear, actionable diagnostics and support for advanced Avro features such as logical types and complex nested schemas.