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Schema & format comparison guides

These guides answer the decision-stage question the validators do not: not how do I validate this format, but which format should I pick in the first place — and, where two checks are easily confused, which check am I actually asking for. Each one is a focused, side-by-side comparison — what each side models, how it evolves, where it is strong, and which to reach for in a given job — written to stand on its own so you can read just the comparison you need. Where the validators are task tools for a format you have already chosen, these guides are for the choice that comes before it.

When a guide helps you settle on a format, head straight to its validator to check your schema — every comparison links to the relevant tools, and validation always runs entirely in your browser, so nothing you paste ever leaves your device. The comparison set below is small and high-intent by design; we add a pair only when it earns a genuinely distinct, accurate comparison rather than a near-duplicate page.

Schema & serialization formats

  • JSON Schema vs Avro

    JSON Schema validates and constrains JSON documents; Avro is a compact binary format built for schema evolution. When to use each, and how they compose.

  • Protobuf vs Avro

    Two binary serialization formats: Protobuf compiles a .proto IDL with numbered field tags; Avro is JSON-defined and schema-on-read. How they differ on schema and evolution, and which to choose.

  • Well-Formed vs Valid XML

    Two different questions about one file: does it obey XML's syntax rules, and does it obey the schema that governs it? What each check catches, and which validator answers which.

API & config formats

  • OpenAPI vs GraphQL

    OpenAPI describes a REST/HTTP API as paths and methods; GraphQL serves a typed graph from one endpoint. How they differ on fetching, caching and tooling, and which to choose.

  • YAML vs TOML

    Two readable config formats: YAML nests data with indentation; TOML uses explicit tables and brackets. How they differ on nesting, typing and readability, and which to choose.