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Developer tools / Code formatter6 tools

Best online code formatters

Tidy and beautify code in many languages. Facts come from each tool's own pages, and every score says where it comes from. How we rank

Tools
6
Researched
4
Free option
2
Only listed
2

Ranked by signals we can measure or quote: website health, the facts each tool's own pages state, and community discussion. Nothing here has been hands-on tested yet, so this is not a quality test. How the signals rank works

Quick answer

  • No signup needed: JSON Formatter

Based on what each tool's own pages say. A tool is left out when its pages say it varies or do not say. Details are listed under each tool.

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Want two of these head to head? Compare tools side by side.

  • 1

    JSONLint

    UnclearSignup unclearFile handling unclearHealth 3.9
    Open JSONLint
    Details and sources
    Free tier
    Not stated.
    Paid plan
    Not stated.
    Signup
    Not stated.
    Watermark
    Not stated.
    Where files go
    All JSON validation happens client-side in your browser, and data is never sent to servers. The page says: “All JSON validation happens client-side in your browser. Your JSON data is never sent to our servers for processing.”

    From the tool's own pages, checked 2026-11-08. Sources: Privacy. Prices and limits change; check the tool before you rely on them.

    Read automatically by a program, not by a person. Each fact quotes the sentence it came from, and a fact is shown only if that sentence is on the page. Where a page did not say, it reads “Not stated.”

    Full page for JSONLint

  • 2

    Code Beautify

    UnclearSignup unclearFile handling unclearHealth 3.8
    Open Code Beautify
    Details and sources
    Free tier
    Not stated. The pages show no pricing or premium tiers and do not say whether the tools are free.
    Paid plan
    Not stated.
    Signup
    Not stated. Login is mentioned for saving links and keeping saved data private; the pages do not say an account is needed to use the tools.
    Watermark
    Not stated.
    Where files go
    Privacy policy says 99% of tools process data in the browser using JavaScript. It says no data is stored unless the user uses the Save Online feature. For uploads and URL loading, data goes between server and client, and uploaded files are deleted immediately or by a scheduled job. Public saved data can be indexed by Google.

    From the tool's own pages, checked 2026-11-01. Sources: Home page, Privacy policy. Prices and limits change; check the tool before you rely on them.

    Full page for Code Beautify

  • 3

    Beautifier.io

    Free optionSignup unclearFile handling unclearHealth 3.5
    Open Beautifier.io
    Details and sources
    Free tier
    The source code is completely free and open, available on GitHub under the MIT licence. The page says: “All of the source code is completely free and open, available on GitHub under MIT licence.”
    Paid plan
    Not stated.
    Signup
    Not stated.
    Watermark
    Not stated.
    Where files go
    Not stated.

    From the tool's own pages, checked 2026-11-08. Sources: Home. Prices and limits change; check the tool before you rely on them.

    Read automatically by a program, not by a person. Each fact quotes the sentence it came from, and a fact is shown only if that sentence is on the page. Where a page did not say, it reads “Not stated.”

    Full page for Beautifier.io

  • -

    JSON Formatter

    Free optionNo signupFile handling unclear—
    Open JSON Formatter
    Details and sources
    Free tier
    The JSON Formatter is a free tool for formatting, validating, saving, and sharing JSON data. The page says: “JSON Formatter is free to use tool which helps to format, validate, save and share your JSON data.”
    Paid plan
    Not stated.
    Signup
    An account is not required to save and share code, though login is required for private saves and specific link expiry options. The page says: “No. It's not required to save and share code. If JSON data is saved without login, it will become public. To make json data private please login and save the links.”
    Watermark
    Not stated.
    Where files go
    JSON data is validated and processed within the user's browser. The page says: “Your JSON Data gets validated in the browser itself.”

    From the tool's own pages, checked 2026-11-08. Sources: Home. Prices and limits change; check the tool before you rely on them.

    Read automatically by a program, not by a person. Each fact quotes the sentence it came from, and a fact is shown only if that sentence is on the page. Where a page did not say, it reads “Not stated.”

    Full page for JSON Formatter

Answers come from each tool's own pages (“Unclear” means they do not say). Tick “Compare” on two to four tools to read them side by side.

Also listed (2, not yet tested)

Each of these answered when we visited its site. We have not tested them or recorded facts, so they are in alphabetical order, not ranked.

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