What HTML errors does ValidateHTML check for?

ValidateHTML checks for unclosed tags, missing required attributes, deprecated HTML elements, incorrect tag nesting, missing DOCTYPE, invalid attribute values, accessibility issues, and more.

Is ValidateHTML free to use?

Yes, ValidateHTML is completely free. You can validate unlimited HTML code snippets and URLs at no cost. No registration required.

How is the HTML quality score calculated?

Your HTML quality score starts at 100. Each error deducts 10 points and each warning deducts 3 points. Grades: A (90-100), B (75-89), C (50-74), D (25-49), F (below 25).

Does HTML validation affect SEO?

Yes. Clean markup improves crawlability, reduces rendering errors, and ensures search engines can properly parse your content. Valid HTML also improves accessibility, which is increasingly important for SEO.

Page Size Checker

Enter a URL to check the total weight of a web page. Analyze size, load time, compression, and caching headers.

Why Page Size Matters

Page size directly impacts how fast your website loads. Larger pages take longer to download, especially on mobile networks and slower connections. Google has confirmed that page speed is a ranking factor for both desktop and mobile search results.

Beyond SEO, page weight affects user experience and conversion rates. Research shows that 53% of mobile users abandon sites that take more than 3 seconds to load. Every additional 100 KB of page weight adds measurable latency, particularly on 3G and 4G connections.

Heavy pages also consume more bandwidth, which matters for users on metered connections and for your hosting costs at scale. Optimizing page size is one of the highest-leverage performance improvements you can make.

Ideal Page Size Guidelines

Under 500 KB

Excellent

Your page is lightweight and will load fast on virtually any connection. This is the ideal target for most web pages, especially content-focused sites.

500 KB – 1 MB

Good

Acceptable for most websites. Ensure images are optimized and compression is enabled. Most well-built pages fall in this range.

1 MB – 2 MB

Needs attention

Getting heavy. Review images, remove unused CSS/JS, and ensure gzip or Brotli compression is enabled. Users on slower connections will notice delays.

2 MB – 5 MB

Heavy

Too large for most pages. Likely caused by unoptimized images, large JavaScript bundles, or embedded media. Significant impact on mobile performance.

Over 5 MB

Critical

Severely overweight. Will cause poor Core Web Vitals scores and high bounce rates. Immediate optimization is needed across images, scripts, and assets.

How to Reduce Page Size

Optimize Images

Use modern formats like WebP or AVIF. Compress images, serve responsive sizes with srcset, and lazy-load below-the-fold images.

Enable Compression

Enable gzip or Brotli compression on your server. This typically reduces HTML, CSS, and JS file sizes by 60–80%.

Minify CSS and JavaScript

Remove whitespace, comments, and unused code. Use tools like Terser for JS and cssnano for CSS. Tree-shake unused imports.

Remove Unused Code

Audit your CSS and JS bundles for unused code. Tools like PurgeCSS can remove unused CSS rules. Split code to load only what is needed.

Set Cache Headers

Configure Cache-Control headers so returning visitors do not re-download unchanged assets. Use long max-age with content hashing.

Reduce Third-Party Scripts

Each analytics, chat, or ad script adds weight and requests. Audit third-party scripts regularly and remove any that are not delivering value.

Use a CDN

Serve static assets from a content delivery network. CDNs reduce latency by serving files from edge locations closer to users.

Defer Non-Critical Resources

Use defer or async for non-critical JavaScript. Load fonts with font-display: swap. Inline critical CSS and lazy-load the rest.

Frequently Asked Questions

What does page size include?

Page size refers to the total weight of the HTML document itself. The full page weight including all resources (images, CSS, JS, fonts) would be larger. Our tool measures the HTML document size and analyzes its weight, compression, and caching configuration.

What is a good page load time?

Google recommends that pages load in under 2.5 seconds (measured by Largest Contentful Paint). For the HTML document alone, aim for under 500ms Time to First Byte (TTFB). Our tool measures the response time for the HTML document.

Does page size affect SEO rankings?

Yes. Page speed is a confirmed Google ranking factor through Core Web Vitals. Larger pages take longer to load, which increases Largest Contentful Paint (LCP) and can push your scores below the "good" threshold, negatively affecting rankings.

What is gzip compression and why does it matter?

Gzip is a compression algorithm that reduces the size of text-based files (HTML, CSS, JS) during transfer. Brotli is a newer alternative that achieves even better compression ratios. Enabling either typically reduces transfer size by 60–80%.

How is page weight different from page size?

The terms are often used interchangeably. Technically, page size can refer to just the HTML document, while page weight usually includes all resources needed to render the page (HTML, CSS, JS, images, fonts, etc.).

How do I check if compression is enabled?

Our tool checks the Content-Encoding response header. If it shows gzip or br (Brotli), compression is enabled. You can also check using browser DevTools in the Network tab by looking at the response headers.