YAML to TONL Converter

Example: YAML input and real TONL output

The output below was generated by the same conversion code the converter uses, run on this sample when the page was built.

service:
  name: checkout-api
  image: registry.example.com/checkout:2.4.1
  replicas: 3
env:
  LOG_LEVEL: info
  DB_POOL_SIZE: 10
ports:
  - 8080
  - 9090
healthcheck:
  path: /healthz
  intervalSeconds: 15

#version 1.0
root{env,healthcheck,ports,service}:
  env{DB_POOL_SIZE,LOG_LEVEL}:
    DB_POOL_SIZE: 10
    LOG_LEVEL: info
  healthcheck{intervalSeconds,path}:
    intervalSeconds: 15
    path: /healthz
  ports[2]: 8080,9090
  service{image,name,replicas}:
    image: "registry.example.com/checkout:2.4.1"
    name: checkout-api
    replicas: 3

TONL output is 66% larger than the YAML input. The same data is 214 characters as minified JSON and 295 as pretty-printed JSON. Sizes are character counts, not tokens: token counts depend on the model's tokenizer (see the tokenizer comparison).

YAML to TONL: what changes

• Reading YAML: Comments are dropped and anchors/aliases are expanded into copies. Unquoted values such as 2021 or 1.0 are read as numbers; quote them in the YAML if they must stay strings.
• Writing TONL: TONL output starts with #version 1.0 and a root key, lists field names in braces, and sorts keys alphabetically. On small payloads the header and per-object field lists make it larger than TOON; TONL earns its place through its query, schema, and streaming tooling.

Why Convert YAML to TONL?

Use TONL when you want a compact text format plus tooling around it: querying, schema validation, or streaming. For plain prompt compression, TOON is usually the simpler choice.