Which website builder is best for SEO? What 743 sites get wrong

The short answer

The study cannot name a best website builder for SEO, and neither does this page. It counts technical SEO problems on sites built with each builder.[1] Sites on every one of the seven had problems; what differs is which ones.

What the study measured

• Which sites. Sites drawn at random, with a fixed seed, from the Tranco list of popular domains, between rank 1,000 and rank 1,000,000.[1]
• How they were crawled. Up to 1,000 pages and 90 minutes per site, reading the HTML as served.[1]
• Which sites count. A site counts when its crawl finished and at least 10 of its pages answered normally (HTTP 200).[1]
• How many. 743 sites that count, out of 892 crawled, from 174,192 domains tried. v1 snapshot, 7 Nov 2026.[1]

Where the builders differ most

The six warning-level problems with the widest gap between platforms. Each figure is the share of sites that count with the problem on at least one page.[1]

Each line below sets the platform with the highest share beside the lowest of the five platforms that have 100 or more sites that count.[1]

• HSTS max-age under 180 days. The site tells browsers to keep to HTTPS for less than 180 days. On 95.6% of Shopify sites that count (109 of 114 sites), against 0% of Webflow sites (0 of 116 sites).[1]
• Microdata markup is broken. Structured data written as microdata has an error in it. On 93.8% of Squarespace sites that count (106 of 113 sites), against 4.3% of Webflow sites (5 of 116 sites).[1]
• Protocol-relative resource links. A script, stylesheet or image address starts with // and not with https://. On 97.4% of Shopify sites that count (111 of 114 sites), against 54.2% of WordPress sites (58 of 107 sites).[1]
• Images missing alt attribute. An image has no alt attribute. On 85.1% of Shopify sites that count (97 of 114 sites), against 19.8% of Webflow sites (23 of 116 sites).[1]
• Internal links point at URLs robots.txt disallows. A page links to an address that the site’s own robots.txt tells crawlers not to fetch. On 79.6% of Squarespace sites that count (90 of 113 sites), against 14.7% of Webflow sites (17 of 116 sites).[1]
• No main landmark. The page marks no main region for screen readers. On 87.1% of Webflow sites that count (101 of 116 sites), against 13.2% of Shopify sites (15 of 114 sites).[1]

Builder by builder

Shopify: 114 sites

The three most common warning-level problems on these sites: More in what 114 Shopify sites get wrong.

• Heading hierarchy skips levels: 99.1% of sites that count (113 of 114).[1]
• Protocol-relative resource links: 97.4% of sites that count (111 of 114).[1]
• The same social card on every page: 96.5% of sites that count (110 of 114).[1]

WooCommerce: 109 sites

The three most common warning-level problems on these sites: More in what 109 WooCommerce sites show.

• Heading hierarchy skips levels: 98.2% of sites that count (107 of 109).[1]
• Links with no anchor text: 93.6% of sites that count (102 of 109).[1]
• Missing meta description: 92.7% of sites that count (101 of 109).[1]

WordPress: 107 sites

The three most common warning-level problems on these sites: More in what 107 WordPress sites get wrong.

• Heading hierarchy skips levels: 92.5% of sites that count (99 of 107).[1]
• Links with no anchor text: 87.9% of sites that count (94 of 107).[1]
• Missing meta description: 87.9% of sites that count (94 of 107).[1]

Webflow: 116 sites

The three most common warning-level problems on these sites: More in what 116 Webflow sites show.

• Heading hierarchy skips levels: 100% of sites that count (116 of 116).[1]
• Unsafe cross-origin links (target=_blank without noopener): 95.7% of sites that count (111 of 116).[1]
• Links with no anchor text: 93.1% of sites that count (108 of 116).[1]

Squarespace: 113 sites

The three most common warning-level problems on these sites: More in what 113 Squarespace sites show.

• Heading hierarchy skips levels: 98.2% of sites that count (111 of 113).[1]
• Page is canonicalised to another URL: 97.3% of sites that count (110 of 113).[1]
• Unsafe cross-origin links (target=_blank without noopener): 97.3% of sites that count (110 of 113).[1]

Wix (94 sites that count) and custom-built sites (90) are in the table above only: in the study, a platform gets a section of its own once 100 or more of its sites count.[1]

What this does not show

The study’s own limits, word for word:

• Search outcomes. Nothing here says whether these problems cost traffic or rankings.
• Cause. A figure describes sites built on a platform. It mixes platform defaults with owner choices and with the kind of site each platform attracts.
• Sites we could not crawl fully. If sites that refuse or block crawlers differ from the rest, the figures lean toward sites that are easy to crawl. The number left out is published with each version.
• Every page of large sites. Crawls stop at 1,000 pages; the number of sites that hit the cap is published with each version.
• Pages after JavaScript. Figures read the HTML as served. Speed (LCP, CLS) and accessibility need a browser and are not measured.
• Individual sites. No site is named, and the downloads hold totals only, one row per platform and problem.

How to use this when you choose a builder

Choose a builder for what you need to sell or publish. Then check your own site, whichever builder it is on: our free SEO audit is a real crawl of up to 25 of your pages, with no account. What an SEO audit checks explains what it looks at.