YAML Diff

What is this tool?

This page is a free YAML diff and YAML compare utility: you paste or edit two YAML documents— Original (left) and Modified (right)—and see changes highlighted in real time. The primary view is a Monaco diff editor with YAML syntax coloring, optional split or inline layout, fullscreen mode, and toolbar actions (sample, clear, swap). A second panel shows a classic line diff—side-by-side aligned rows or a unified patch-style view—with copy and download. Small Valid / Invalid YAML badges reflect parse status per side; invalid YAML still diffs as text, so you can compare broken drafts while fixing them.

Privacy: comparison runs in your browser. Share link copies a URL that embeds both documents in the fragment (hash)—typical for collaboration without uploading files to our servers.

Why compare YAML online?

YAML appears everywhere in modern stacks: Kubernetes manifests, Helm values, docker-compose, GitHub Actions, GitLab CI, Ansible, Argo CD Applications, OpenAPI specs in YAML, Spring application.yml, and cloud IaC templates. Reviewing a PR or reconciling staging vs production values is faster when you can see exactly which keys and lines moved—without committing to a local Git diff for every paste from Slack or email.

This tool is line-oriented: it treats YAML as text for the lower panel (same engine as our Text Diff). That respects comments, anchors, and formatting choices that a pure JSON round-trip might erase—though it also means reordering keys shows as many line changes even when the parsed data matches.

Key features

• Monaco YAML diff — VS Code–engine highlighting, folding, word wrap, synchronized scrolling in split mode.
• Split / Inline — Toggle side-by-side panes or inline diff in the Monaco view.
• Fullscreen — Expand the editor (Escape to exit); line-diff panel hides until you exit fullscreen.
• Sample, Clear, Swap — On the editor toolbar for fast workflows.
• Line diff panel — Side-by-side rows or unified + / − output; copy or save as yaml-diff.txt.
• Per-side YAML validation — Same parser family as our YAML Validator; badges update as you type.
• Share link — Base64-encoded pair in the URL hash for reopening both sides.
• Local persistence — Last pair restored from localStorage on return visits.

How it works (step-by-step)

1. Load content — Paste Original and Modified YAML, use Sample, or open a shared URL.
2. Edit in Monaco — Both sides are editable; changes propagate to React state so the line diff stays in sync.
3. Pick a Monaco layout — Split for parallel review; Inline for a compact single-pane diff.
4. Read the line diff — Switch Side by side vs Unified; counts show approximate added/removed lines.
5. Export or share — Copy unified text, download, or copy a shareable link.

YAML diff vs JSON diff vs plain text diff

Quick example

A tiny ConfigMap-style change: one value edited and one key added. The Monaco view colors diff regions; the unified section shows −/+ lines.

# Original                          # Modified
data:                                data:
  LOG_LEVEL: info                      LOG_LEVEL: debug
  FEATURE_X: "true"                   FEATURE_X: "true"
                                      FEATURE_Y: enabled

Use cases

Best practices

• Normalize first when whitespace noise dominates — Run both sides through the YAML Formatter if you only care about semantic changes and comments are not critical (formatting may alter presentation).
• Validate syntax — Use YAML Validator for deep focus on parse errors; this diff page surfaces badges but optimizes for comparison.
• Watch line endings — CRLF vs LF can inflate diffs; normalize in your editor when comparing exported files.
• Prefer Share for reviews — Colleagues reopen the exact pair; avoid pasting multi-hundred-line YAML into chat when a link suffices.
• Huge documents — Browser tabs may slow with very large inputs; consider splitting files or using Git locally for multi-megabyte streams.

Limitations

• Not a Kubernetes schema linter — Valid YAML can still be invalid for a given CRD or API version; use cluster tooling for admission-level checks.
• Line diff is not semantic YAML — Equivalent maps with different key order or spacing show as textual differences.
• Share URL length — Extremely large payloads may exceed practical URL limits; use download or split content.
• Multi-document streams — Multiple --- documents diff as text; ordering matters for alignment.

FAQ

Related terms & search phrases

Compare YAML: yaml diff online, yaml compare tool, compare two yaml files, yaml difference checker, diff yaml side by side, kubernetes yaml diff online, helm values diff, docker compose yaml compare, github actions yaml diff, gitlab ci yaml compare, openapi yaml diff, ansible yaml compare, spring boot yaml diff.

Workflow: paste yaml diff, browser yaml merge review, client-side yaml comparison, monaco yaml diff editor, unified yaml patch export, yaml syntax validate while diffing.

Similar tools

Explore related Spoold utilities:

• YAML Formatter
• YAML Validator
• JSON Diff
• JSON ↔ YAML
• Text Diff
• TOML Formatter

Conclusion

YAML Diff combines a Monaco YAML comparison experience with downloadable unified output, fullscreen editing, validation hints, and shareable links—ideal for engineers reviewing manifests, CI YAML, and configuration drafts without leaving the browser. Pair it with the YAML Formatter, YAML Validator, and JSON Diff when your workflow spans normalized JSON trees and formatted YAML configs.