TONL to YAML Converter

Input TONL

or drop a file anywhere

Output YAML

Your YAML appears here as you type.

Paste data to see token savings

Convert TONL to YAML with our free online converter.

Example: TONL input and real YAML output

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

TONL input (228 characters)

#version 1.0
root:
  events[4]{latencyMs,level,service,ts}:
    42,info,auth,"2026-09-30T08:12:04Z"
    310,warn,billing,"2026-09-30T08:12:09Z"
    38,info,auth,"2026-09-30T08:12:15Z"
    1204,error,search,"2026-09-30T08:12:21Z"

YAML output (348 characters)

events:
  - latencyMs: 42
    level: info
    service: auth
    ts: '2026-09-30T08:12:04Z'
  - latencyMs: 310
    level: warn
    service: billing
    ts: '2026-09-30T08:12:09Z'
  - latencyMs: 38
    level: info
    service: auth
    ts: '2026-09-30T08:12:15Z'
  - latencyMs: 1204
    level: error
    service: search
    ts: '2026-09-30T08:12:21Z'

YAML output is 53% larger than the TONL input. The same data is 329 characters as minified JSON and 505 as pretty-printed JSON. Sizes are character counts, not tokens: token counts depend on the model's tokenizer (see the tokenizer comparison).

TONL to YAML: what changes

Reading TONL: TONL documents start with a #version line and wrap the data in root. The TONL encoder writes object keys in alphabetical order, so the original key order is not kept.
Writing YAML: Strings that would otherwise change type on re-read, such as '2021' or '1.0', are quoted. No comments are generated.

About TONL

TONL (Token-Optimized Notation Language) is a compact text format that maps one-to-one to JSON and ships with a query API, schema validation, and streaming. Savings are roughly 32-45% versus JSON in the TONL project's own measurements.

✓Lossless round trip to JSON
✓Query and aggregation API
✓Schema validation (TSL)
✓Streaming for large files

Full TONL Documentation →

About YAML

YAML is a human-friendly data serialization format. It uses indentation instead of brackets, making configuration files more readable.

✓Human readable
✓No punctuation
✓Supports comments
✓Great for config

Full YAML Documentation →

Why Convert TONL to YAML?

Use YAML for configuration files, especially in DevOps (Docker, Kubernetes, GitHub Actions). It's more readable than JSON but can have ambiguity with indentation.

TONL to YAML: Frequently Asked Questions

How do I convert TONL to YAML?

Paste your TONL into the editor on json2toon.co. The tool detects the input and produces YAML instantly, then you copy the result. Conversion runs entirely in your browser, so nothing is uploaded to a server.

Is the TONL to YAML converter free?

Yes. Converting TONL to YAML on json2toon.co is free with no account, signup, or usage limit. A free public API is also available for automated, programmatic conversion.

Why convert TONL to YAML?

Convert TONL to YAML with our free online converter.

What should I watch out for when converting TONL to YAML?

Strings that would otherwise change type on re-read, such as '2021' or '1.0', are quoted. No comments are generated.

Is my data safe when I convert TONL to YAML?

Yes. The TONL to YAML conversion happens client-side in your browser. Your source data stays on your device and is never sent to or stored on a server, which makes it safe for private or sensitive payloads.