YAML Tools

YAML Viewer — Tree & Code View

Explore any YAML document as an interactive tree — mappings, lists, and counts at a glance, anchors resolved.

In short

View YAML online as a collapsible tree or highlighted code: explore nested mappings and lists, counts per branch, anchors resolved. Free, no upload.

By NaveenKumar T · Updated 17 Sep 2026

Learn: YAML Anchors, Aliases and Merge Keys Explained (With Real Config Examples)

Collapsible tree view
Anchors & aliases resolved
Item & key counts per node

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Example

YAML Viewer: input and output

A two-service docker-compose fragment — nested mappings and a list of ports, the shape the Tree view is built to make scannable.

Input · yaml

services:
  api:
    image: nv-toolkit/api:1.4.2
    ports:
      - "3000:3000"
    environment:
      NODE_ENV: production
    depends_on:
      - db
  db:
    image: postgres:16

Output · yaml

services:
  api:
    image: nv-toolkit/api:1.4.2
    ports:
      - 3000:3000
    environment:
      NODE_ENV: production
    depends_on:
      - db
  db:
    image: postgres:16

Notice the quoted port mapping "3000:3000" loses its quotes on the way out — the library only quotes a scalar when the surrounding context actually requires it, and a colon inside a sequence item isn't one of them.

Learn more

Reading YAML structurally

Deeply nested YAML is hard to read precisely because indentation is the only structural cue — at six levels deep, telling sibling from child is squint work. The tree view replaces indent-counting with explicit branches: fold what you don't need, read counts instead of scrolling, and follow any path without losing your place.

Because the viewer fully parses the document first, it also doubles as validation: files that render in the tree are guaranteed loadable by your tooling.

Where the viewer earns its keep

Reviewing a 800-line Kubernetes manifest someone attached to a ticket, verifying which values an Ansible inventory ACTUALLY nests where, and inspecting Helm chart values files before an upgrade — three minutes of scrolling becomes three clicks of folding.

Help

Frequently asked questions

Everything you need to know about the YAML Viewer.

01How do I use the YAML Viewer?

Paste YAML or drop a file — the document opens directly in Tree view with every mapping and list foldable. Switch to Code for the normalized text, or Expand/Collapse all to control depth.

02How does the viewer show anchors, aliases, and multi-line strings?

Anchors and aliases are resolved before display — every *alias shows the actual anchored content, so what you see is what consumers get. Block scalars (| and >) appear as their final string values with line breaks intact.

03What happens to the tree if my YAML has a syntax error?

The tree doesn't render a partial or best-guess structure — YAML parsing is all-or-nothing, so a broken document shows the error's exact line and column instead of a tree with a hole in it. That's deliberate: a tree built around a guess would hide exactly the mistake you need to see. Fix the reported position and the full structure appears on the next pass.

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