YAML Diff Viewer

YAML Diff Viewer compares two YAML files side-by-side and highlights every difference — added lines (green), removed lines (red), and changed values (orange). It supports three views: side-by-side, unified diff, and semantic key-level diff. Everything runs in your browser.

Side-by-side shows both files next to each other with colored highlights per line. Unified shows a classic git-style diff with + and − prefixes. Semantic parses both YAML files and shows key-level changes — which keys were added, removed, or changed — regardless of line position.

The semantic view parses both YAML files into flat key-value maps (supporting nested keys like server.host) and compares the maps directly. This means it catches value changes even if surrounding lines moved, and ignores whitespace or comment-only differences. Useful for config file reviews.

The tool uses a lightweight browser-side YAML parser focused on common config file patterns (scalars, mappings, sequences). Complex YAML features like anchors (&alias), aliases (*alias), merge keys (<<), and multi-document (---) separators are not fully supported. For full YAML spec compliance, use a server-side tool.

No. All diffing runs entirely in your browser. Your YAML content — which may contain API URLs, credentials, or internal hostnames — never leaves your machine. Safe for sensitive config files.

Common use cases: comparing Kubernetes manifests before and after a change, reviewing docker-compose.yml updates, checking if a GitHub Actions workflow changed between versions, auditing Helm chart values.yaml differences, or comparing environment-specific configs (dev vs prod).