Skip to content
Convertto

JSON Merge

Deep-merge several JSON documents, choosing how arrays and conflicts are resolved.

JSON merge combines several documents into one, recursing into nested objects so configuration layers accumulate rather than replacing each other wholesale. Later documents win on conflict, and arrays can be replaced, concatenated or unioned depending on what you need.

Runs in your browser
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

What is the difference between a shallow and deep merge?

A shallow merge replaces a nested object wholesale, so merging {a:{x:1}} with {a:{y:2}} loses x. A deep merge recurses and keeps both. Configuration layering almost always wants deep; state updates often want shallow.

Which document wins a conflict?

The later one, by convention, because configuration is normally layered as defaults first and environment overrides last. Reversing the order reverses which value survives.

How to use the json merge

  1. 1Enter or paste your json documents.
  2. 2Choose the arrays.
  3. 3Turn "Pretty-print" on or off as needed.
  4. 4The result appears immediately — copy or download it.

Embed this tool

Put the working json merge on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

Share this tool

Related tools

.env to JSON ConverterConvert .env files to JSON and back — for config migrations and CI variables.INI & Config File ParserParse INI, .conf, .cfg and .properties files into structured JSON, YAML or TOML.Data Format ConverterConvert between JSON, YAML, XML, CSV, TSV and TOML in any direction, locally in your browser.JSON DiffCompare two JSON documents and see exactly which keys were added, removed or changed.JSON FlattenerFlatten deeply nested JSON into dot-notation keys, or expand flat keys back into nested objects.JSON Formatter & ValidatorFormat, validate, repair and analyse JSON — with errors that point at the exact line.

Last updated

More data & format tools