HTML Tools
8 free tools · 100% client-side
Beautify, minify, validate, and preview HTML online in a fast, private, browser-based workspace.
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Most-used HTML Tools
HTML Formatter
Prettier-quality HTML formatting — embedded CSS and JavaScript formatted too, with a live preview one click away.
HTML Validator
Catch the unclosed <div> before it breaks your layout — structural validation with line numbers, instantly.
HTML Minify
Smaller pages, identical rendering — comments stripped and whitespace collapsed with pre/script/style protected.
All 8 HTML Tools
HTML Formatter
Prettier-quality HTML formatting — embedded CSS and JavaScript formatted too, with a live preview one click away.
HTML Validator
Catch the unclosed <div> before it breaks your layout — structural validation with line numbers, instantly.
HTML Viewer
Paste markup, see the page — sandboxed live preview beside prettier-formatted source.
HTML Editor
VS Code editing with a rendered preview beside it — highlighting, auto-closing tags, format on demand.
HTML Minify
Smaller pages, identical rendering — comments stripped and whitespace collapsed with pre/script/style protected.
JADE to HTML
Indentation in, angle brackets out — Jade/Pug templates expanded to clean HTML with a rendered preview.
HTML to JADE
Angle brackets in, clean indentation out — HTML collapsed to idiomatic Jade/Pug shorthand.
EXCEL to HTML
Copy cells in Excel, paste here, get a clean semantic table — escaped, previewable, ready for any page.
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From tag soup to readable markup
HTML accumulates entropy: CMS exports arrive on one line, email templates nest tables six levels deep, and scraped markup mixes tabs with spaces. The HTML Formatter restores consistent indentation with embedded CSS and JavaScript formatted in place; the Validator checks structural sanity — unclosed tags, mis-nested elements — and the Viewer renders markup in a sandboxed preview so you can see what a fragment actually produces without leaving the page.
For production, HTML Minify strips comments and collapses whitespace to shrink payloads, and the live-preview Editor pairs an editing pane with rendered output for quick template iterations. The Jade/Pug converters translate between indentation-based templates and plain HTML in both directions, and Excel to HTML turns pasted spreadsheet ranges into clean <table> markup.
Private by construction
Markup often contains things that shouldn't travel: unpublished page designs, customer data baked into templates, internal URLs. Like every NV Toolkit page, the HTML tools parse and render entirely in your browser — the preview runs in a sandboxed iframe on your machine, nothing posts to a server, and the tools work offline once loaded. Paste with confidence.
Help
Frequently asked questions
Everything you need to know about the HTML Tools.
01Will formatting change how my HTML renders?
Almost never — formatting only rewrites inter-tag whitespace, and HTML collapses runs of whitespace when rendering. The one caveat is whitespace-sensitive contexts like <pre> or white-space: pre elements, which the formatter leaves untouched for exactly that reason.
02Is the HTML preview safe for untrusted markup?
The preview renders inside a sandboxed iframe without same-origin privileges, so scripts in pasted markup can't touch your session or other tabs. It's designed for inspecting templates and fragments — though as with any untrusted content, your own judgment applies.
03How much does HTML minification actually save?
Typically 10–25% on hand-written templates (comments, indentation, blank lines) and less on already-tight markup. The minifier reports exact before/after sizes — combined with gzip or brotli on your server, readable source costs almost nothing in production.
Learn the format
Guides for html tools
HTML Entities Explained: When to Escape &, <, > and Quotes
Which characters to escape in HTML text, attributes, URLs and scripts, how named, decimal and hex references differ, and why you keep seeing &amp;.
9 min readGuide · Developer ToolsFreeFormatter Alternatives (2026): Where Its Tools Went
FreeFormatter.com has been retired and its tool pages now return 404. A verified map of where each formatter, validator, escaper and encoder moved.
6 min readGuide · Data FormatsHow to Convert Excel to JSON (Without Writing Code)
Turn Excel or Google Sheets data into clean JSON in under a minute: paste cells directly or export CSV — with typed numbers, booleans, and proper quoting.
2 min read