A JSON formatter Chrome extension turns raw JSON in a browser tab into readable, indented text, often with colours and a collapsible tree. Nearly every listing has the same name, so the publisher, the users count and the ratings count are what tell them apart. Eight follow in no particular order.
Open a raw API response in Chrome and you'll get one long line of brackets and quotes. A formatter extension lays it out so you can read it, and the Chrome Web Store has plenty of them, almost all called JSON Formatter or something very close.
To keep them apart, each name below carries its publisher in brackets, the way the store's Offered by line shows it. They're listed alphabetically and in no particular order, with every store number as of Oct 2026. If you test APIs often, my guide to how API testing tools help web developers covers the next step up.
Eight JSON formatters with almost the same name
Type and Good for come from each listing's own description. None of the eight says on its listing that it's free, so every cell in the last column reads Not stated, as of Oct 2026.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| JSON Formatter (cafeboy.org) | JSON formatter, open source | Making JSON readable, from an open source listing | Not stated |
| JSON Formatter (callumlocke.com) | JSON formatter | Making JSON easy to read in the browser | Not stated |
| JSON Formatter (json-formatter.js.org) | JSON formatter with themes | Auto formatting with 60+ themes and syntax highlighting | Not stated |
| JSON Formatter (jsonlint.com) | JSON formatter | Colour coded, structured JSON | Not stated |
| JSON Formatter (shiftshift.app) | JSON formatter and validator | Formatting, validating and minifying JSON locally | Not stated |
| JSON Formatter and Viewer (webtoolworld.com) | JSON formatter, viewer and validator | Collapsible tree, validation and error repair | Not stated |
| JSON Formatter and Viewer for Chrome (zmime.com) | JSON formatter and beautifier | Formatting and beautifying JSON | Not stated |
| JSON Formatter Pro (Google Sites page) | JSON viewer with sidebar | Search, copy paths, export, pin nodes and history | Not stated |
Eight ways to read JSON in Chrome
JSON Formatter (cafeboy.org)
Best for: Readable JSON from an open source extension whose short description closely matches the biggest listing's, so check the publisher line carefully.
JSON Formatter (callumlocke.com)
Best for: Formatting JSON in the tab, from the listing with by far the most users here, though its average is the lowest on this page.
JSON Formatter (json-formatter.js.org)
Best for: Developers who like to choose their colours, with 60+ themes, syntax highlighting and clickable links in an open source formatter.
JSON Formatter (jsonlint.com)
Best for: Turning raw JSON into a structured, colour coded layout, from the publisher jsonlint.com, whose listing shows only a handful of ratings.
JSON Formatter (shiftshift.app)
Best for: Formatting, validating, minifying and copying JSON locally, opened from a command palette inside Chrome.
JSON Formatter and Viewer (webtoolworld.com)
Best for: Checking and repairing broken JSON as well as formatting it, with a collapsible tree view and error detection.
JSON Formatter and Viewer for Chrome (zmime.com)
Best for: A simple formatter and beautifier from zmime.com, with no ratings shown and a last update on February 6, 2024.
JSON Formatter Pro (Google Sites page)
Best for: Browsing JSON with a sidebar for search, copying paths, exporting, pinning nodes and history, from a publisher with a Google Sites page.
Same name, very different JSON listings
JSON Formatter (callumlocke.com) has 2,000,000 users as of Oct 2026, far more than any other here, yet it shows a 1.5 average from 2.1K ratings. At the other end, JSON Formatter (shiftshift.app) shows 85 users, and JSON Formatter and Viewer (webtoolworld.com) shows a 5.0 average from just 2 ratings.
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A huge user count with a low average isn't much to go on, and neither is a perfect average from two people. Read the users count, the ratings count and the average together, then the last updated date, which runs from February 6, 2024 to August 16, 2026 across these eight. Two of them even share almost the same short description, so the Offered by line is the one thing you can't skip.
Which kind of JSON extension for which job
- You just want API responses readable in a tab: pick a plain formatter.
- You often deal with broken JSON: pick one whose listing mentions validation or repair.
- You care about colours: pick one that offers themes.
- You open huge responses: pick a viewer with a collapsible tree or a sidebar.
- You prefer the keyboard: pick one you open from a command palette.
When you are debugging a page, a tool for editing cookies is the natural companion, and cookie editor extensions compares the choices.
Checking a JSON formatter before you add it
- Match the Offered by line, not the title, because the title's the same on almost all of them.
- Check the users count, the ratings count and the average together.
- Look at the last updated date, so you know when it's last had attention.
- Check what site access it asks for when you add it, and remove it if that's more than a formatter needs.
- If you open sensitive data, look for a listing that says it formats locally or privately.
Do you make a JSON formatter for Chrome? Tool makers can ask to be considered for a featured place on this list.
My plain advice on JSON formatter extensions
Choose by publisher, then by the numbers on the listing. A plain formatter is all most people need, and the extras (themes, validation, a sidebar) don't matter unless you'll use them every day. Whatever you pick, check what it can read in your browser, because you'll be opening API responses in it.
For the wider toolkit around it, my guide to developer productivity tools that work is a good next read.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
What does a JSON formatter Chrome extension do?
It takes raw JSON open in a tab and lays it out with indents, and often colours and a collapsible tree, so you can read it.
Why are there so many JSON Formatter extensions?
Lots of publishers use the same plain name, so the title won't tell you who made it. Look at the Offered by line on each listing, because that's where they differ.
Which JSON formatter has the most users?
On this list, one listing shows 2,000,000 users as of Oct 2026, far ahead of the rest, though its average rating is 1.5.
Is it safe to format JSON in a browser extension?
Be careful with sensitive data. Check what site access an extension asks for, and look for listings that say they format locally or privately.
Are JSON formatter extensions free?
None of the eight listings here says so, so this page marks them Not stated as of Oct 2026. Check the listing before you add one.
