Why do yes, no and on need special care in YAML?

Older YAML parsers (following YAML 1.1) treat unquoted yes, no, on, off, true and false as booleans rather than strings — so a country code of NO (Norway) or a setting genuinely meant to be the string "yes" can silently become a boolean. Quoting the value explicitly avoids the ambiguity.

YAML Sample Generator

Generates a small, self-contained YAML fixture — service config, user record, pipeline stages — for testing a parser or documenting a config shape without writing one from scratch.

Don't repeat what I've already seen

Your result will appear here.

What you'll get

This generator draws from a hand-checked list of 8 entries. Here is a spread of 6 of them, so you can see the style before you generate:

name: sample-service version: 1.4.0 env: staging features: - search - export replicas: 3
user: id: 4821 name: Sample User active: true roles: - viewer - editor
database: host: localhost port: 5432 ssl: false pool_size: 10
settings: theme: dark notifications: true language: en-GB
product: sku: SKU-48213 price: 19.99 currency: GBP in_stock: true
job: name: nightly-export schedule: "0 2 * * *" retries: 3 enabled: true

A fixed sample of the list, not a live draw — your own results are picked at random from all 8, without repeating until the list runs out. Original authoring for Generate Random — illustrative fixture-style YAML, no real service configuration.. Last reviewed 2026-07-18.

How to use this tool

Press generate for a YAML sample.
Copy it, or generate again for another one.

Common use cases

Testing a YAML parser
Documentation config examples
Quick fixture data

Limitations and good to know

8 fixed fixtures. They cover common shapes at a glance rather than YAML's fuller feature set — anchors, multi-document files and explicit tags do not appear in any of them.
Each is a small, flat-ish structure for readability; real config files are often deeper and larger.
These are fictional samples, not a real service's actual configuration schema — treat field names as illustrative rather than as a spec to code against.

Practical tips

Validate the sample before relying on it; YAML's indentation rules make it easy to produce something that parses differently from how it reads.
Watch for values like `yes`, `no` and `on` — older YAML parsers read them as booleans rather than strings.

Entries are chosen with your browser's cryptographic random number generator, so every entry on the list is equally likely. How Generate Random works.

Frequently asked questions

Why do yes, no and on need special care in YAML?: Older YAML parsers (following YAML 1.1) treat unquoted yes, no, on, off, true and false as booleans rather than strings — so a country code of NO (Norway) or a setting genuinely meant to be the string "yes" can silently become a boolean. Quoting the value explicitly avoids the ambiguity.