Server-rendered pages, email templates, and CMS output arrive minified or with indentation that has drifted through a dozen edits.
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HTML Formatter
Html
Free · API · MCPToolYour platform
Use HTML Formatter three ways
The free HTML Formatter on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse HTML Formatter here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is HTML Formatter?
Server-rendered pages, email templates, and CMS output arrive minified or with indentation that has drifted through a dozen edits. This HTML formatter runs the markup through Prettier with a hundred-character print width, producing consistent indentation and predictable attribute wrapping so a diff shows what actually changed.
Because Prettier parses before it prints, badly broken markup fails with an error rather than being silently reflowed — useful feedback in itself. What it will not do is repair your document: unclosed tags, misnested elements, and duplicate attributes are the browser's problem, and no formatter fixes semantics. It does not execute scripts, resolve templates, or render anything. For JSX and JavaScript, JS Formatter uses the babel parser instead, and CSS Formatter handles style blocks you have extracted.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/html-formatter and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about HTML Formatter?
Does it fix invalid HTML?
No. It formats what parses and errors on what does not. Structural problems such as misnested tags still need fixing by hand.
Can it format a template language?
Only plain HTML reliably. Handlebars, Twig, or Blade syntax embedded in the markup may not survive the HTML parser.
What about JSX?
Use JS Formatter for JSX and TSX, which runs the babel parser and understands JavaScript expressions inside markup.
What are the key features of HTML Formatter?
Prettier-backed output
The same formatter your editor probably runs, so results match your repository style.
Parse errors surfaced
Markup that cannot be parsed fails loudly instead of being silently reflowed.
Review-friendly wrapping
Consistent attribute wrapping keeps diffs small and readable.
How do you use HTML Formatter?
Paste the markup
A rendered response, a template fragment, or an email body.
Format it
Read the indented structure and check the nesting is what you expected.
Review or minify
Use the formatted version for review; compress separately when shipping.
Reading rendered output during debugging
Formatting a response body answers questions that are hard to see otherwise. Did the template actually run — unresolved placeholders stand out immediately in indented markup. Is the structure what the component intended — a wrapper that renders twice, or a list rendering one item too many, becomes obvious once nesting is visible.
What did the CMS inject — analytics snippets, injected styles, and third-party widgets often explain a layout shift or a slow page, and they hide well in a single-line document. Formatting first, then reading, is faster than scrolling through minified output looking for a tag.
The formatter family
Four formatters in this category cover the front-end and data languages. HTML here, CSS Formatter for stylesheets, JS Formatter for scripts, and XML Formatter for markup that is not HTML.
The first three are Prettier-backed and therefore parse before printing, which means formatting doubles as a syntax check. Once the code is readable and correct, CSS Minifier and JS Minifier handle the opposite direction for quick size comparisons.
Which formatter and utility tools sit in this cluster?
Where do you browse more developer tools tools?
- Developer Tools tools
Browse the full Developer Tools category on ToolYour.
- Marketing Tools tools
Build UTM links, check ads copy limits, QA email subjects, and calculate ROAS/CPC/CTR — free in the browser; R
- Security Tools tools
Check HTTP security headers, TLS, cookies, JWTs, passwords, hashes, and SPF/DKIM/DMARC — free in the browser;
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