Online Code Formatter: Beautify JavaScript, HTML, CSS, and SQL

What Is Code Formatting

Code formatting (Beautify / Prettify) adjusts source to a consistent style — indentation, line breaks, quote style, semicolons, and more. An online formatter lets you clean messy snippets in the browser without installing Node or Prettier first. Open our Code Formatter, pick a language and indent style, then format.

Why You Need Code Formatting

1. Team consistency: Shared style reduces review noise about spaces so people focus on logic
2. Readability: Clear structure helps onboarding and debugging
3. Surfacing syntax issues: Failed parses often reveal missing braces or broken tags immediately
4. Cleaner diffs: Reviews show fewer irrelevant whitespace changes

Supported Languages and Engines

ToolVault's Code Formatter covers four common front-end / data snippets:

JavaScript

Powered by Prettier (babel parser):

• Unified quotes and semicolons (opinionated defaults; not per-toggle on the page)
• Wrapping for objects and arguments, trailing commas
• Configurable indent: 2/4 spaces, or tabs

HTML

• Nested tag indentation
• Attribute wrapping and self-closing normalization
• Minify uses the HTML helper — not the JS minifier by mistake

CSS

• Expanded rule blocks and property spacing
• Complements the dedicated CSS Minifier: format here when you need to read, minify there when you need extra CSS options

SQL

• sql-formatter for keyword case and indentation (follows the indent controls)
• Exotic dialects and stored procedures still belong in a dedicated SQL workflow or local config; see the SQL formatter guide for deeper dialect options

How to Use

1. Paste code into the input
2. Select the language (JavaScript / HTML / CSS / SQL)
3. Choose indent: 2 spaces, 4 spaces, or Use tabs
4. Click Format for readable layout; parse errors include line/column when available
5. Click Minify for a language-matched compress pass and read the character / UTF-8 byte delta

What the Indent Controls Change

Quotes, semicolons, and print width stay on Prettier defaults. If the team has a full .prettierrc, the IDE/CI wins — the online tool is for instant formatting without a project config, not a replacement for repo rules.

Side-by-side example

// Input (one line)
function greet(name){if(name){return `Hello, ${name}!`}return "Hello!";}

// After format with 2-space indent
function greet(name) {
  if (name) {
    return `Hello, ${name}!`;
  }
  return "Hello!";
}

Format vs Minify: Two Ends of the Same Snippet

Formatting and minification share one workspace, opposite directions:

When minify helps: quick size checks, shrinking email/inline fragments, comparing readable source vs a ship-shaped blob. Production pipelines should still minify via webpack / esbuild / Terser; this tool does not mangle identifiers.

For dedicated JS or CSS options (drop console, shorten colors), use the JS Minifier and CSS Minifier.

Parse Errors and Line Numbers

Pasted fragments often miss braces or closing tags. When format fails:

• Messages include (line:col) or an equivalent line/column hint when the engine provides it
• The page surfaces that location so you can edit the input and retry

That beats a wall of red text with no pointer. Errors from the minify path (for example an unsupported language) state the reason directly.

Security Considerations

• Client-side: Code stays in the browser
• Server-side: Uploading source to a remote formatter risks leakage

ToolVault runs fully client-side (Prettier standalone + dynamically loaded sql-formatter).

Online Tool vs Local Prettier

Idempotency still matters: formatting already-formatted code should not keep reshuffling. A CI check of format → format again → empty diff prevents phantom blame noise.

Formatters vs linters vs beautifiers

A beautifier mostly reflows whitespace; an opinionated formatter also picks structural defaults (brace placement, line length — Prettier’s philosophy); a linter finds semantic issues (unused variables, suspicious patterns). Mixing jobs wastes time: using a linter’s --fix for style fights itself, while a formatter happily prettifies dead code. Practical split: format with a formatter (hooked in CI), lint for semantics only, and stop debating what machines already settle.

FAQ

Does Formatting Change Code Logic?

No. Prettier and sql-formatter adjust presentation (whitespace and style), not business semantics. Behavior stays the same when the input is syntactically valid.

My Code Got Longer After Formatting — What Now?

Expected: indent and line breaks add bytes. Use Minify on the same page, or a dedicated minifier, when size matters. Production size should be judged on build output plus transport compression (gzip/brotli).

Why Can’t I Toggle Single Quotes or Semicolons?

The page intentionally exposes indent only, so it does not become a mini config center. Quote/semicolon choices stay on Prettier’s defaults; team rules belong in project config, not in one-off paste toggles.

What's the Difference Between Online Tools and Local Prettier?

Same engine family (standalone). The gap is integration: local Prettier hooks into save, full configs, and monorepos; online fits machines without Node, quick size contrasts, and demos.

Triage notes

The online page deliberately exposes only indentation and no quote or semicolon options, stating the reason outright: it should not become a mini configuration center — team conventions belong in .prettierrc, not in checkboxes re-ticked on every paste. The division-of-labor table institutionalizes that split: long-term repository consistency belongs to IDE + CI, while the online tool handles ad-hoc formatting when no project config exists. Parse errors carry line and column numbers because that beats a wall of red with no idea where to start. The idempotence section even includes a copy-paste CI check — format twice and assert an empty diff — which is exactly what guards against phantom diffs.

A ToolVault engineering note. More free local-first tools at the homepage.