A slow landing page on Webflow, Squarespace or Wix: what you can change and what you cannot

Measure first, and measure honestly

Google's web.dev names three user-facing measures and their good thresholds: Largest Contentful Paint of 2.5 seconds or less, Interaction to Next Paint of 200 milliseconds or less, and Cumulative Layout Shift of 0.1 or less, each judged at the 75th percentile of real page loads. Those are field measurements. web.dev is clear that lab testing, such as running a speed tool on your own computer, is useful for catching problems but is not a substitute, and Lighthouse cannot measure interaction latency at all.

So treat any single lab score as a clue. A fair test uses the same tool and settings every time, takes the median of several runs, and records the spread. Then add the number that does not vary: how many bytes the page transfers, and which files and scripts make them up.

• Run the same test five times and keep all five.
• Record total transferred weight with the cache disabled.
• Sort every file by size; a few usually account for most of it.

What you control on each builder

Squarespace's guidance is specific: keep a page to about 5 MB or less, images under 500 KB with a width of 1500 to 2500 pixels, galleries to 50 images and pages to 60 blocks. Its slow-loading article also lists too many fonts (about two is the advice), custom code, external scripts and even a very long list of URL redirects as causes.

Wix handles a lot for you: it resizes uploaded images, converts them to modern formats and lazy-loads by default. What stays with the owner is what goes above the fold, how many videos and animations are used, fonts (it suggests three or four and prefers system fonts), third-party apps and iframes, and lightboxes, which load later by design. Wix advises converting animated GIFs to video.

Webflow's update note says new images lazy-load by default, existing images are not changed, and the load setting can be switched per image, so a large image at the top of the page may need to load eagerly while those below it load lazily.

• Reduce fonts to the few the design needs.
• Replace animated images with video where the builder suggests it.
• Check each image's load setting rather than assuming it.

Third-party scripts are the hidden weight

Chat widgets, trackers, schedulers and embedded videos come from other servers, and no builder can tune them. Wix says it cannot optimise content from third-party apps and iframes and suggests putting them on a secondary page with a button to it. For scripts you must keep, it advises the defer attribute, which tells the browser not to wait for the script, placement near the end of the body, and the marketing integrations instead of pasted copies.

Removing a script is a business decision, not a speed trick. A tracking tag might feed advertising reports; a widget might take bookings. That is why a speed fix lists what each item costs and asks you to decide.

• List every third-party host on the page and its weight.
• Decide for each: keep, defer, move to another page, or remove.
• Re-test forms and tracking after any removal.

What the builder does not let you change, and acceptance

None of the help articles we read offers a setting for server configuration or caching rules; the levers they describe are all on the page itself. That means the realistic gains come from image sizes, fonts, videos and scripts, and a promise to pass a particular score or to move search ranking would be a promise about things outside the page.

The fixed-scope speed fix of one page is priced at £345 as an untested proposal and paid only after you sign off. The budget is agreed only if it asks for at least 20% less weight and at least 20% less Largest Contentful Paint time than the baseline; otherwise the job stops and nothing is charged. It is accepted when total weight is at or below the figure agreed from the baseline, the median of five repeat Lighthouse runs meets the agreed Largest Contentful Paint time with no worse blocking time, no image exceeds the agreed limit, and desktop and phone views show no change beyond the named items. A monthly weight and speed check is available as a separate standing service.