Merge Two JSON Objects Online (Deep Merge)
Merge two JSON objects (deep merge), the second overriding the first, in your browser.
🔒 100% client-side — no data sent
Deep-merge two JSON objects: nested objects are combined and the second JSON overrides the first when keys conflict. Perfect for combining configurations or applying overrides. The tool runs 100% in your browser with no data upload.
What is it for?
- ▸ Combine a base configuration with an environment override
- ▸ Merge two API responses into a single JSON object
- ▸ Apply default values to a settings object
- ▸ Consolidate multiple i18n translation files
FAQ
What is the difference between a shallow merge and a deep merge?
A deep merge recursively combines nested objects instead of replacing a key entirely, which preserves sub-properties from both JSON objects.
Which JSON takes priority on conflict?
When keys conflict, the value from the second JSON overrides the first. Unique keys from both objects are kept.
How are arrays merged?
By default, an array from the second JSON replaces the one from the first rather than concatenating elements, to avoid unwanted duplicates.