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Compare JSON

Find every added, removed and changed key between two JSON files.

  • Free
  • No signup
  • Nothing uploaded
  • No watermark

Paste JSON on both sides and the differences appear here.

Original

Changed version

How to Compare Two JSON Objects by Key

Compare JSON: before and after JSON A BEFORE COMPARE JSON JSON A AFTER

A plain text diff of two JSON files is noisy. Reordered keys, different indentation and a trailing newline all show up as changes even when the data is identical. This tool parses both sides and compares the actual values, so only real differences are listed.

Paste the original JSON on the left and the changed version on the right. The list of differences appears as soon as both sides are valid, each with its full path, such as users[2].email, and the old and new values.

No software to install Free Works on any device

Steps to Diff JSON Data

  1. 1. Paste the original

    Put the first JSON document in the Original box. It can be an API response, a config file or an export.

  2. 2. Paste the changed version

    Add the second document in the Changed version box. If either side is not valid JSON, a message names that side and the problem.

  3. 3. Read the differences

    Each line is marked + for added, - for removed, ~ for a changed value and a double arrow when the type changed, for example from a number to a string.

  4. 4. Ignore array order if needed

    Tick Ignore array order when lists hold the same items in a different sequence and you do not want that reported.

No .json file to hand? Download a sample JSON file (3.5 KB) and try it.

Try it now

What Is a Structural JSON Diff?

Instead of comparing text line by line, a structural diff reads both documents as data and walks through them key by key. Key order and whitespace are ignored because they do not change the meaning. What remains are keys that were added or removed, values that changed, and values whose type changed.

Why Compare Files Side by Side?

Reading two versions by eye is slow, and small changes slip past even careful readers. A comparison puts both copies next to each other and marks every added, removed and changed line, cell or word, so nothing gets missed.

“The change you do not notice is the one that causes trouble later.”
  • Every change marked in colour
  • Catch edits before you sign
  • Check data after an import
  • Both files stay on your device
  • No more reading line by line
  • Spot quiet changes in contracts
  • Review code before it goes live
  • Proof that nothing else changed

Popular Uses for File Comparison Tools

People reach for a comparison whenever two copies of something might not match.

  • Contract revisions See exactly which clauses the other side changed before you agree to the new draft.
  • Spreadsheet checks Find the cells that changed between last month’s price list and this month’s.
  • Thesis drafts Compare your latest chapter with the version your guide marked up last week.
  • Code reviews Look at two versions of a script or stylesheet and see each line that moved.
  • Database schemas Check two CREATE TABLE statements or schema dumps before running a migration on live data.
  • Design proofs Place two images together to spot a moved logo or a changed colour.
  • Config files Compare JSON, YAML or INI settings between a working server and a broken one.
  • Policy updates See what really changed in a revised policy PDF instead of trusting the summary.

What the JSON Compare Tool Reports

Exact paths

Every difference comes with a path like settings.theme or items[0].price, so you can find it in a large file.

Four kinds of change

Added, removed, changed value and changed type, each in its own colour.

Array order option

Compare lists as unordered collections when the order of items does not matter to you.

Side-specific errors

Invalid JSON is reported for the side that is actually broken, so you fix the right file.

Instant result

The comparison updates as you type or paste, with no button to press.

Why Use ToolXkit for Compare JSON?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

Comparison Tools for Different Users

Lawyers and legal staff

Check each new draft of an agreement against the one already approved.

Students

Compare an edited essay with the original to learn from every correction made.

Developers

Review changes in code, config and SQL without setting up a separate diff program.

Accountants

Match two versions of a ledger or price sheet and find the stray figures.

Editors and writers

See what a co-author or client changed in a manuscript between two rounds.

HR teams

Confirm that an updated contract or handbook differs only where it was meant to.

Best Times to Compare Two Files

A side-by-side comparison helps when you are:

  • Reviewing a returned contract
  • Checking a reissued price list
  • Preparing code for release
  • Planning a database migration
  • Hunting a settings mismatch
  • Reading a co-author’s edits
  • Sorting out two saved copies
  • Checking a revised design proof

Tips for Comparing JSON

  1. Compare API responses from staging and production to spot a field that one environment has dropped.

  2. Leave Ignore array order off for config files, where the order of a list often has meaning.

  3. A change from 42 to "42" is flagged as a type change. That is a frequent cause of bugs between systems.

  4. To compare files rather than pasted text, open each in a text editor and copy the whole contents into each box.

Frequently Asked Questions

Answers to common questions about this tool.

How do I compare two JSON files online?

Copy the contents of each file and paste them into the Original and Changed version boxes. Differences are listed straight away with their paths. All of the matching runs locally, and neither document travels over the internet.

Does key order matter?

No. {"a":1,"b":2} and {"b":2,"a":1} are reported as identical because JSON objects have no meaningful key order. Formatting and indentation are ignored as well.

What does ignore array order do?

It treats each list as a collection of values, so [1, 2, 3] and [3, 1, 2] match. Without it, items are compared by position and a reordered list shows as changes.

Why does it say one side is not valid JSON?

Common causes are trailing commas, single quotes, comments, or text copied with extra characters around it. The message names the broken side and shows where parsing failed.

Can it compare very large JSON files?

It can handle large documents, limited mainly by your device’s memory. Very big files take longer to parse, and the list of differences may be long, so compare smaller sections when you can.

Is Compare JSON free, and do I need an account?

Yes. It costs nothing, and there is nothing to sign up for. Open the page, add your two files or paste two blocks of text, and the differences appear. There is no trial period and no limit on how often you compare.

Are my files uploaded when I use Compare JSON?

No. Both files are read by your browser and compared on your own computer or phone. Nothing is sent to a server, which matters when the documents are contracts, salary sheets or private code.

Can I compare two different formats, like a PDF and a Word file?

Each compare tool is built for one kind of file, such as PDF, Excel, JSON or plain text. To compare across formats, convert one of them first, or copy the text of both into Compare Text.

How big can the files be?

There is no fixed cap. Everything runs in your browser, so very large files depend on how much memory your device has. A laptop handles bigger files than an older phone, and closing other tabs can help.

Will Compare JSON show formatting changes as well as text?

It depends on the tool. Most compare tools focus on content, such as words, lines, cells or values, because that is where meaningful changes hide. Compare PDF Visually is the one to use when the look of the page matters.

Further reading

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