Strings and booleans
Under YAML 1.2 Core, true and false are booleans, while values such as yes normally remain strings. YAML 1.1 compatibility can interpret a broader set.
Inspect structure without flattening references
Build and search a YAML document tree
The local worker parses YAML with yaml version 2.9.0, returns a bounded display model, and keeps alias nodes as references. YAML 1.2 Core Schema is the default, YAML 1.1 is optional, and merge-key expansion remains disabled.
Loading the private YAML tree viewer…
Enable JavaScript to explore YAML locally. The tree model, alias boundary, type, and size guidance below remains readable.
Move from indentation to structure
How to view and explore YAML online
The tree is an inspection aid. It does not edit the source, execute configuration, or replace the schema-aware tools used by the target platform.
- 1
Paste a YAML stream
Include one document or several documents separated by
---. Choose YAML 1.2 Core unless the actual consumer requires YAML 1.1 scalar resolution. - 2
Build the local tree
Mappings, sequences, scalars, alias references, and document boundaries receive rows; anchors and tags are shown on their owning rows. Block scalar values are shown as text rather than executable content.
- 3
Search and collapse
Filter displayed keys, indices, types, and values or collapse a mapping or sequence to focus on nearby structure. Display state never changes the YAML input.
YAML is a graph-shaped data model
What the YAML viewer represents
A YAML document is not merely an indented JSON object. Mappings associate keys with values, sequences retain item order, and scalars resolve under a selected schema. Anchors name nodes and aliases refer back to those nodes, which means the representation can be a graph rather than a pure tree. Tags can also participate in type resolution.
The viewer presents a bounded tree-shaped outline while keeping each alias as a reference row. It does not copy or recursively expand the anchored node under every alias. This avoids disguising shared identity as repeated source and prevents an alias-heavy document from creating a disproportionately large display. Merge-key expansion is likewise disabled.
Comments and presentation details belong to the YAML source model, while the tree focuses on document structure and resolved scalar information useful for inspection. Use the YAML Formatter when the goal is a new serialization, and compare that serialization with the original because formatting can change presentation.
- Mapping
- Key/value pairs whose keys must be unique under the validator policy.
- Sequence
- An ordered collection whose rows retain their numeric item positions.
- Scalar
- A value resolved according to YAML 1.2 Core or explicit YAML 1.1 behavior.
- Alias
- A reference to an anchored node, displayed without recursive expansion.
The selected schema changes interpretation
Read YAML scalar types carefully
Numbers and null
Plain scalar spelling affects numeric resolution. A tree type label helps reveal when an unquoted token did not remain the string the author expected.
Block scalar text
Literal and folded block styles have distinct newline semantics plus chomping controls. Inspect the value and keep the original source nearby when exact text matters.
Custom tags
A visible tag is metadata, not permission to construct a class or execute code. This page is an inspector; downstream loaders define their own tag behavior and risk.
Inspection remains bounded
Large YAML, aliases, and incomplete views
Input is limited to 200,000 UTF-16 code units and parsed in a browser worker. The returned display is also bounded so a very deep or broad document cannot create unlimited rows in the page. If the interface reports truncation, the outline is incomplete; absence from the displayed tree is not evidence that a node is absent from the source.
Aliases remain reference rows even when the anchored node is small. This is a semantic and availability boundary, not a defect: expanding aliases could multiply repeated content and blur the difference between written nodes and references. Use a controlled application loader if you specifically need a resolved object graph, with its own limits and trust policy.
The document is not uploaded or placed in the URL. Browser extensions, clipboard history, screen capture, backups, and other local software remain outside that promise. Redact secrets from production configuration whenever a synthetic example can reproduce the issue.
Need conversion instead?
Open JSON to YAML →
The YAML-to-JSON converter applies a different, explicit rule set: aliases may expand up to a limit, multiple documents become an array, and unsupported keys or tags stop conversion.
Open YAML to JSON →Open JSON to YAML →
Viewer behavior
YAML viewer FAQ
Does the YAML viewer expand aliases?
No. Anchors and aliases are represented in the tree, but alias references are not recursively expanded. The viewer does not duplicate an anchored subtree beneath each alias.
Can the YAML viewer show multiple documents?
Yes. A YAML stream separated by document markers is represented as distinct documents rather than merged into one object.
Does viewing YAML validate a Kubernetes or Compose schema?
No. The viewer parses supported YAML syntax for display. It does not validate Kubernetes, Docker Compose, CI, OpenAPI, or application-specific schemas.
Does collapsing or searching change the YAML?
No. Those controls affect only visible rows. The source remains untouched, and the viewer does not produce an edited download.