---
title: YAML Validator — Validate & Format YAML Online
url: https://varstatt.com/toolkit/yaml
description: Validate YAML syntax with inline errors and line numbers. Tree view, auto-format, and common template samples for Kubernetes, Docker, and GitHub Actions.
section: Developer Toolkit (https://varstatt.com/toolkit)
tags: data
related: JSON (https://varstatt.com/toolkit/json), JSON ↔ YAML (https://varstatt.com/toolkit/json-yaml), YAML (https://varstatt.com/toolkit/yaml)
---
# YAML Validator

Validate YAML syntax with inline errors and line numbers. Tree view, auto-format, and common template samples for Kubernetes, Docker, and GitHub Actions.

## How It Works

1. **Paste or type YAML** — Enter YAML in the editor. Validation happens in real-time as you type.
2. **Check for errors** — Errors show the exact line and column. Valid YAML displays a green indicator and parsed tree view.
3. **Format or load samples** — Auto-format to fix indentation. Load Docker Compose, GitHub Actions, or Kubernetes samples to test.

## FAQ

### What YAML version is supported?

YAML 1.2 via the js-yaml library, which is the current standard used by most tools and platforms.

### Why is my YAML invalid?

Common issues: inconsistent indentation (mixing tabs and spaces), missing colons, or unquoted special characters.

### Can I validate Kubernetes manifests?

This tool validates YAML syntax, not Kubernetes schema. For schema validation, use kubectl --dry-run or a dedicated K8s linter. Need to convert between JSON and YAML? Use the [JSON-YAML converter](https://varstatt.com/toolkit/json-yaml).

## Usage

This tool runs entirely in the browser — visit the URL above to use it.

Prefill inputs via URL parameters:

- `https://varstatt.com/toolkit/yaml?input=...`

## Related Tools

- [JSON](https://varstatt.com/toolkit/json)
- [JSON ↔ YAML](https://varstatt.com/toolkit/json-yaml)
- [YAML](https://varstatt.com/toolkit/yaml)