Free online JSON merge tool. Deep merge recursively merges nested objects, shallow merge only merges top-level keys, array concat merges arrays by concatenation. Real-time preview. Pure frontend.
Deep merge recursively merges nested objects. Shallow merge only merges top-level keys, nested objects are replaced by B.
When both values are arrays, they are concatenated instead of overridden.
Completely safe. All merging happens locally in your browser.