JSON Merge Online - Free Browser Tool

Conflict policy

Arrays

Input — separate documents with "--- doc"

Tip: use samples, upload, copy, download, and send-to actions inside the workspace where available.

What is JSON Merge?

JSON Merge is a free, browser-based tool that helps you get the job done quickly. Deep-merge two or more JSON documents with conflict policy. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.

How to use JSON Merge

1Paste or drop your JSON into the workspace.
2Adjust the available options to suit your data.
3Copy or download the result — it never leaves your browser.

Features

Fast, focused, and easy to use
100% client-side — no upload, fully private
Free with no account, no watermark, and no daily limit
Works on large inputs, limited only by your device's memory
Load a sample, then copy, download, or share your result

Common uses

Migrating data between APIs, databases, and spreadsheets
Quick one-off data jobs without opening a heavy app
Preparing data before importing it elsewhere
Sharing a reproducible result with a teammate via a link

Used by

Data engineers
Backend developers
API developers
Data analysts

Examples

Example 1

Example input

Paste or upload the data you want to process with JSON Merge.

Example output

JSON Merge returns a clean result you can inspect, copy, download, or continue using in DataXForge.

Example 2

Simple case

A small input for JSON Merge

Immediate result

A focused result you can review before copying or downloading.

Example 3

Custom case

Input with changed settings or options

Adjusted result

The output updates to match your selected options.

Example 4

Review case

A value you want to double-check before using elsewhere

Reviewable output

The result gives you a safer handoff into the next task.

Example 5

Workflow case

Input prepared by another DataXForge tool

Next-step result

The output can be copied, downloaded, or used in another browser workflow.

Common errors

Input is copied from a source with hidden whitespace or encoding issues.
The result is not reviewed before being reused elsewhere.
The wrong options are selected for the target workflow.
The original data is not kept for comparison.

How it works

1Accepts the input for JSON Merge.
2Runs the operation in the browser.
3Returns a result you can copy, download, or continue using.

Recommended workflow

1
Prepare the input
Use this tool as the focused step in a larger browser-based workflow.
2
Run JSON Merge
Review the preview, copy or download the result, and keep everything local in your browser.
3
Next recommended tool
JSON Compare: Side-by-side diff of two JSON documents with structural alignment.
Open tool
4
Then continue with
JSON Formatter: Pretty-print, minify, and indent JSON safely.
Open tool
5
Then continue with
JSON Validator: Validate JSON syntax with helpful error messages.
Open tool

Frequently asked questions

How do I use JSON Merge?: Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Deep-merge two or more JSON documents with conflict policy.
Is my data uploaded or stored anywhere?: No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.
Is JSON Merge free?: Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.
What's the maximum file size?: There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.
Do I need to install anything?: No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.

What is JSON Merge?

Examples

Example 1

Example input

Paste or upload the data you want to process with JSON Merge.

Example output

JSON Merge returns a clean result you can inspect, copy, download, or continue using in DataXForge.

Example 2

Simple case

A small input for JSON Merge

Immediate result

A focused result you can review before copying or downloading.

Example 3

Custom case

Input with changed settings or options

Adjusted result

The output updates to match your selected options.

Example 4

Review case

A value you want to double-check before using elsewhere

Reviewable output

The result gives you a safer handoff into the next task.

Example 5

Workflow case

Input prepared by another DataXForge tool

Next-step result

The output can be copied, downloaded, or used in another browser workflow.

Recommended workflow

Prepare the input

Use this tool as the focused step in a larger browser-based workflow.

Run JSON Merge

Review the preview, copy or download the result, and keep everything local in your browser.

Next recommended tool

JSON Compare: Side-by-side diff of two JSON documents with structural alignment.

Open tool

Then continue with

JSON Formatter: Pretty-print, minify, and indent JSON safely.

Open tool

Then continue with

JSON Validator: Validate JSON syntax with helpful error messages.

Open tool

Frequently asked questions

How do I use JSON Merge?

Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Deep-merge two or more JSON documents with conflict policy.

Is my data uploaded or stored anywhere?

No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.

Is JSON Merge free?

Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.

What's the maximum file size?

There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.

Do I need to install anything?

No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.