YAML Merger
Merge two YAML documents with configurable precedence, deep or shallow object merging, and array replace or concat behavior. Perfect for environment overrides, config composition, and deployment workflows.
Complete Guide: YAML Merger
Everything you need to know about using this tool effectively
The YAML Merger combines two YAML documents into a single YAML output using deep merge logic. When both documents have the same key, the second document's value takes precedence. Nested objects are merged recursively. Arrays from the second document replace arrays from the first. The tool validates both inputs and shows the merged result. All processing happens in the browser.
This tool parses both YAML inputs into JavaScript objects, performs a deep merge where the second object's properties override the first, then re-serializes the result as YAML. The merge is recursive for nested objects, so partial overrides work correctly.
Merging Helm values overrides
Combine a base values.yaml with environment-specific overrides into a single merged file.
Applying config layering
Merge a default configuration with a user-specific configuration where user values take priority.
Combining Kubernetes manifests
Merge two Kubernetes resource definitions where the second patches values from the first.
Consolidating CI/CD configs
Merge a base CI/CD configuration with branch-specific overrides.
Paste the base YAML
Enter the first (base) YAML document on the left.
Paste the override YAML
Enter the second (override) YAML document on the right.
Merge
Click Merge. The tool combines the documents with deep merge logic.
Copy the result
Copy the merged YAML or download it as a .yml file.
The second document's values override the first when keys conflict.
Nested objects are merged recursively, so you can override individual subkeys.
Arrays are replaced entirely, not merged element by element.
Validate both inputs before merging to catch syntax errors early.
How does the merge handle conflicting keys?
When both documents have the same key, the second document's value takes precedence. For nested objects, the merge is recursive, so only the differing subkeys are overridden.
How are arrays handled?
Arrays from the second document completely replace arrays from the first. Element-by-element array merging is not supported.
Is my YAML uploaded to a server?
No. All parsing and merging happens in your browser. Nothing is transmitted.
What if one of the YAML files is invalid?
The tool validates both inputs. If either has a syntax error, it reports the error with a line number before attempting the merge.
Can I merge more than two files?
The tool merges two files at a time. To merge multiple files, merge the first two, then merge the result with the next file.