Reliable SQL dialect support; your queries go to a server.
On this page
Scores
Updated
Out of 5, from what each tool does. The reasons are in the reviews below.
Tool
Privacy
Features
Price
Aarrange
5
4
5
Prettier Playground
5
4
5
JS Beautifier
5
2
5
CodeBeautify
1
5
5
Online Tools
1
2
5
SQL Formatter Online
1
1
5
What to look for in a code formatter
Code formatters range from single-language tools to multi-language platforms that handle your whole formatting workflow. Before picking one, it helps to know what actually matters.
Language coverage is the obvious starting point. If you write SQL in the morning and tweak YAML configs before deploying, you don't want three different bookmarks. A tool that covers your full stack saves real time.
Formatting quality matters more than people think. A formatter that handles simple cases but mangles complex SQL joins or YAML anchors is worse than no formatter at all. Look for tools backed by mature parsing libraries.
Editor experience covers what makes a tool pleasant to use daily: syntax highlighting, keyboard shortcuts and responsive performance on large inputs. These feel optional until you're formatting a 2,000-line SQL migration and the page freezes.
Privacy is the factor most developers overlook. Online formatters that process code on a server send your source code, database queries and configuration files to someone else's infrastructure. And anything a site stores can end up public, as the 2025 JSONFormatter and CodeBeautify case showed.
Why privacy matters for code formattersIn November 2025, security researchers at watchTowr Labs reported that code people had saved on JSONFormatter.org and CodeBeautify.com could be read by anyone through the sites' public "Recent Links" pages. They downloaded more than 80,000 saved snippets (over 5 GB), covering five years of JSONFormatter and one year of CodeBeautify, and found Active Directory and database credentials, cloud keys, private keys, API tokens and personal data. Fake AWS keys they planted were tried by someone else within 48 hours. The lesson: assume anything you paste into a server-side tool, and especially anything you save there, can be seen by others. Tools that process everything in your browser avoid this risk.
With those criteria in mind, we tested six free code formatters on real-world inputs: complex SQL queries, nested HTML templates, multi-document YAML files and large JSON payloads. Here is how they compare.
Looking for FreeFormatter?FreeFormatter.com is gone. When we opened it on 15 October 2026, the domain showed a parked "under construction" page with ad links, so it is no longer on this list. It formatted HTML, XML, JSON, SQL and CSS on its server. Aarrange formats all five in your browser, and Online Tools covers the encoders and decoders.
Detailed reviews
We tested each tool with real-world code: SQL queries with CTEs and subqueries, minified HTML pages, deeply nested JSON configs, YAML files with anchors and large CSV datasets. Results are ordered by overall ranking.
01
Aarrange
Most languages in one place; everything stays in your browser.
Nine languages and validators; no JavaScript formatter
Price
Free with no limits
Pros
Everything runs in your browser, so your code never leaves your machine
Covers 9 languages in one toolkit (SQL, HTML, CSS, JSON, YAML, TOML, XML, CSV, Markdown)
CodeMirror 6 editor with syntax highlighting and keyboard shortcuts
No sign-up, no ads, and free with no feature limits
Cons
No JavaScript or TypeScript formatting yet
No dark mode or editor themes
Small site with a smaller community than established alternatives
Most online formatters handle one language, maybe two. Aarrange covers nine (SQL, HTML, CSS, JSON, YAML, TOML, XML, CSV, Markdown) and processes all of them locally in your browser. No sign-up, no ads, and your code is not sent anywhere.
We tested it with a 1,800-line SQL migration and the CodeMirror 6 editor stayed responsive throughout. It has no dark mode or themes, and no JavaScript formatter. If your workflow touches production configs or database queries, processing in the browser matters more than any other feature on this list.
Basic playground: no file upload, no saved settings, limited editor features
Opinionated by design, so formatting options are intentionally limited
If you work with JavaScript or TypeScript, you probably already use Prettier locally. The playground lets you test formatting options without installing anything, and it runs entirely in the browser, so your code stays private.
The trade-off is intentional: Prettier gives you limited control over output style. Teams that want consistency like this. Developers who want to tweak every brace placement will find it frustrating. The playground UI is minimal: paste code, see output. No themes, no file management, no saved sessions.
03
JS Beautifier
Most formatting options for JS, HTML and CSS; nothing else.
Powers the js-beautify library used in VS Code, Atom and Sublime Text
Open source with an active contributor community
Cons
Limited to JavaScript, HTML and CSS. No SQL, JSON or YAML support
Interface is functional but basic
No syntax highlighting or editor amenities
JS Beautifier is the web face of js-beautify, a library that powers formatting in VS Code, Sublime Text and other editors. It handles JavaScript, HTML and CSS, and does all three well.
You get more formatting knobs than most online tools: brace style, operator position, indentation, wrapping and several others. Processing happens in the browser, so your code stays private. The obvious limitation is scope. If you need to format SQL, JSON, YAML or anything outside those three languages, you will need a second tool alongside it.
04
CodeBeautify
Widest language coverage; saved snippets were publicly exposed.
Large library of tools covering most languages and formats
Includes converters, validators and diff tools beyond basic formatting
Free to use with no account required
Cons
Server-side processing: your data is sent to and processed on their servers
Saved snippets, including credentials and keys, were readable by anyone through its public Recent Links page (reported November 2025)
Heavy ad load slows down the experience
Interface feels cluttered and dated
CodeBeautify has one of the largest collections of formatting tools online, covering over 30 languages plus converters and validators. That breadth is useful when you need to format something obscure like SPARQL or Lua.
But processing happens on the server, and in November 2025 watchTowr Labs reported that snippets users had saved on CodeBeautify and its sister site JSONFormatter.org were listed on a public "Recent Links" page. The researchers collected over 5 GB of saved data containing API keys, private keys and database credentials. Our rating reflects that: wide tool coverage, serious trust problem. If you use CodeBeautify at all, limit it to non-sensitive, public code and never press Save on anything private.
Good variety of text processing and conversion tools beyond formatting
Straightforward interface with minimal friction
Free and requires no account
Cons
Server-side processing for all tools
Limited formatting options with few controls
No code editor features, just plain text inputs
Lower formatting quality than dedicated tools
OnlineTools.com is a general-purpose utility site that happens to include code formatters among its many tools. It covers JSON, XML, HTML, CSS and various text manipulation tasks. The formatters work but they are basic: limited configuration, plain text inputs, no syntax highlighting.
Processing is server-side, so your data is sent to their backend. It is most useful for quick text transformations (base64 encoding, URL encoding and so on) when you also need a formatter nearby. For dedicated code formatting, the other tools on this list do a noticeably better job.
06
SQL Formatter Online
Reliable SQL dialect support; your queries go to a server.
Dedicated SQL formatting with solid dialect support
Control over keyword casing (uppercase, lowercase, capitalize)
Handles complex queries with subqueries, CTEs and joins well
Free with no account required
Cons
Server-side processing: your SQL queries are sent to their backend
SQL only, no support for any other language
Dated interface with no modern editor features
No syntax highlighting or dark mode
SQL Formatter Online does one thing and does it reliably. Paste a messy SQL query, pick your dialect (MySQL, PostgreSQL, Oracle or SQL Server) and get clean output. Keyword casing and indentation controls let you match your team's style guide.
The downside: everything is processed on the server. Your queries leave your browser and hit their backend. For SELECT statements on public tables, that is probably fine. For queries that reference internal table names, column names or WHERE clauses that expose business logic, pick a tool that runs in the browser instead.
Search interest
How often people search Google for each tool by name, month by month over five years. It shows which names people know, not how many people use the tool. Google compares at most five names at a time, so this chart joins two searches that share JS Beautifier.
Source: Google Trends, worldwide web search, Oct 2021 to Oct 2026 (Oct 2026 is a part month). This is search interest, not visits: 100 is the busiest month of any name in this chart, and the table shows averages. Fetched 2026-10-14.
Full feature comparison
The feature table covers language support, core features, privacy and editor quality across all six tools.
Feature
Aarrange
Prettier Playground
JS Beautifier
CodeBeautify
Online Tools
SQL Formatter Online
Language support
SQL
Yes
No
No
Yes
No
Yes
HTML
Yes
Yes
Yes
Yes
Yes
No
CSS
Yes
Yes
Yes
Yes
Yes
No
JSON
Yes
Yes
No
Yes
Yes
No
JavaScript / TypeScript
No
Yes
Yes
Yes
No
No
YAML
Yes
Yes
No
Yes
No
No
TOML
Yes
No
No
Partly
No
No
XML
Yes
No
No
Yes
Yes
No
CSV
Yes
No
No
Yes
No
No
Markdown
Yes
Yes
No
Partly
No
No
GraphQL
No
Yes
No
Partly
No
No
Core features
Format / beautify
Yes
Yes
Yes
Yes
Yes
Yes
Minify
Yes
No
No
Yes
No
No
Validate
Yes
Partly
No
Yes
Partly
No
Convert between formats
Yes
No
No
Yes
Partly
No
Privacy and security
Runs in the browser
Yes
Yes
Yes
No
No
No
No data sent to a server
Yes
Yes
Yes
No
No
No
Works offline
Partly
Partly
Partly
No
No
No
No known exposure of user data
Yes
Yes
Yes
No
Yes
Yes
Editor features
Syntax highlighting
Yes
Yes
No
Yes
No
No
Dark mode
No
No
No
Partly
No
No
Customizable themes
No
No
No
No
No
No
Keyboard shortcuts
Yes
Partly
No
Partly
No
No
Language support at a glance
Which languages does each tool actually support? Aarrange covers nine (SQL, HTML, CSS, JSON, YAML, TOML, XML, CSV, Markdown). Prettier Playground covers seven, including JavaScript, TypeScript and GraphQL. CodeBeautify covers the most overall but only partly supports TOML, Markdown and GraphQL. JS Beautifier sticks to JavaScript, HTML and CSS, and SQL Formatter Online does SQL only. The language rows in the feature table below give the full picture.
Privacy audit: where does your code go?
When you paste code into an online formatter, the most important question is simple: does it stay in your browser, or is it sent to a server? After the 2025 JSONFormatter and CodeBeautify case, this stopped being an abstract concern.
Tools that run in the browser (your code stays local)Aarrange, Prettier Playground and JS Beautifier process everything in your browser. No network request carries your code anywhere. You can check this yourself by opening the Network tab in DevTools while you use them. These are the only tools on this list we would use for production credentials, internal queries and proprietary source code.
Server-side tools (your code leaves your machine)CodeBeautify, SQL Formatter Online and Online Tools all send your code to their servers for processing. Once your code is on someone else's server, you depend on how they store it and who can see it. At CodeBeautify and JSONFormatter.org, saved snippets were listed publicly. Avoid pasting anything sensitive into these tools: database queries with real table names, API keys, environment variables, SSH keys or proprietary business logic.
If you work with production databases, internal APIs or code that might contain secrets, processing in the browser is not optional. Even well-known, widely used server-side tools can expose your data. Default to tools that run in the browser, and treat server-side formatters as public playgrounds only.
Our verdict
If you want one tool that covers the widest range of languages while keeping your code private, Aarrange is the pick. It handles SQL, HTML, CSS, JSON, YAML, TOML, XML, CSV and Markdown, all in the browser, all free, no sign-up required. No other tool on this list matches that combination. Try the SQL Formatter.
If JavaScript or TypeScript formatting is your main need, Prettier Playground is a good complement. For granular JS, HTML and CSS control, JS Beautifier gives you the most configuration options.
After researchers pulled more than 80,000 saved snippets from two popular server-side tools, picking a formatter that runs in your browser is worth the five minutes it takes to switch. Your code formatter should format your code, not store it.
FAQ
Which free code formatter covers the most languages without sending my code to a server?
Aarrange. It formats SQL, HTML, CSS, JSON, YAML, TOML, XML, CSV and Markdown, all in your browser, with no sign-up. Prettier Playground also runs in the browser and adds JavaScript, TypeScript and GraphQL, but has no SQL.
Which online formatters send my code to a server?
Of the six tools here, CodeBeautify, SQL Formatter Online and Online Tools process code on their servers. Aarrange, Prettier Playground and JS Beautifier run in the browser.
What happened with JSONFormatter.org and CodeBeautify in 2025?
In November 2025, watchTowr Labs reported that snippets users had saved on the two sites could be read by anyone through their public "Recent Links" pages. The researchers collected more than 80,000 saved entries containing credentials, private keys and API tokens.
What happened to FreeFormatter.com?
The site no longer works. On 15 October 2026 freeformatter.com showed a parked "under construction" page from its domain registrar, with ad links and no tools. For the same jobs, Aarrange formats HTML, XML, JSON, SQL and CSS in your browser, and Online Tools has encoders and decoders.
What is the best online formatter for JavaScript or TypeScript?
Prettier Playground, if you want the same output as the Prettier formatter most teams already use. JS Beautifier gives you more options (brace style, indentation, wrapping) but does not handle TypeScript in our matrix.
Is there a good formatter just for SQL?
SQL Formatter Online by dpriver handles MySQL, PostgreSQL, Oracle and SQL Server dialects with keyword casing controls, but it sends your queries to its server. Aarrange's SQL Formatter runs in the browser.
Aarrange
Prettier Playground
JS Beautifier
CodeBeautify
Online Tools
01
