To speed up your Shopify store before Black Friday, measure first, then cut unused apps and third-party scripts, resize the hero image, fix fonts and test checkout on a phone. Aim for an LCP of 2.5 seconds, INP of 200 milliseconds and CLS of 0.1. Then freeze changes about a week before the sale.
Black Friday falls on November 27 this year and Cyber Monday on November 30. If you read this on November 8, you have roughly two weeks of safe working time. That is enough to fix the biggest problems, but not enough for a rebuild. This checklist is ordered by payoff, so stop when the time runs out.
Where do you start to speed up Shopify store pages?
Start with numbers, because guessing wastes days. Run your home page, one collection page, one product page and the cart through PageSpeed Insights, and write down the scores. Test on mobile, since a large share of your visitors are on a phone. Also open the online store speed report inside your Shopify admin for a second opinion.
Look at the field data at the top of the PageSpeed report before the lab score. Field data comes from real visits. The lab score is one simulated run and it moves around from test to test.
Pick the pages that earn money. Most owners test the home page only. In our client work, the product page and the cart are where a slow script costs the most, so test those first and the home page last.
What targets should you aim for?
Google publishes three Core Web Vitals thresholds, and a page passes when 75% of visits meet them. According to web.dev, those are:
- Largest Contentful Paint (LCP): 2.5 seconds or less.
- Interaction to Next Paint (INP): 200 milliseconds or less.
- Cumulative Layout Shift (CLS): 0.1 or less.
Save a screenshot of each result. You will compare against it on November 20, and it tells you which fix actually worked.
Which apps and third-party scripts should you remove?
Start here. In our client work, a store with a dozen installed apps almost always has two or three that nobody remembers adding. Each one can load JavaScript and CSS on every page, whether the page needs it or not. Removing them is the cheapest way to speed up a Shopify store, and it costs nothing but an afternoon.
Shopify's own theme performance guidance tells developers to audit all scripts, including apps, tracking pixels and theme code, and to remove any that are not worth their cost. It also says to disable A/B test anti-flicker snippets when no test is running.
A quick app audit
- List every app and every tracking pixel in a spreadsheet.
- Mark what each one earns you. Be honest. "Might use it" means remove it.
- Disable one app, retest the product page, and note the change.
- Uninstall what you do not need, then check your theme code for leftover snippets.
That last step matters. Some apps leave code behind in the theme after you uninstall them. Removing the app in the admin does not always remove the script.
Be wary of apps that promise to boost your speed score. Shopify's guidance warns against "fake" performance apps that manipulate Lighthouse results. They improve the number a tool reports, not what a shopper feels.
How do you fix images, the hero and the LCP element?
On most stores the largest thing on the first screen is a hero banner or a product photo. That one element usually sets your LCP, so give it special treatment. Per web.dev's LCP guide, never lazy-load the LCP image, and set the fetchpriority attribute to high so the browser fetches it sooner.
Shopify's guidance adds a few more rules for the hero:
- Use a real image tag, not a CSS background, so the browser finds it early.
- Serve separate mobile and desktop images so a phone does not download the desktop file.
- Give every image a width and height to prevent layout shift.
- Lazy-load only the images below the first screen.
Check your upload sizes too. A 4000-pixel photo shown at 600 pixels wide is wasted bandwidth. Resize the source file, then let Shopify's image tools produce the responsive sizes. Open the product page on your phone afterward and watch what appears first.
Image work is the second-fastest way to speed up a Shopify store after the app cull. One resized hero takes under an hour, and you can see the effect in your next PageSpeed run.
What about a hero video?
Cut it or replace it for the sale. A video above the fold competes with everything else for bandwidth on the first load. Use a sharp still image as the hero, and move the video lower on the page or behind a play button. It looks less fancy. It also loads faster, and shoppers on Black Friday want the deal, not a film.
Is your theme slowing you down?
Sometimes. A theme heavy with sliders, animations and bundled features pays for them on every page. Open the theme editor and look at the home page sections. Do you need the carousel, the countdown widget, the video background and the Instagram feed all at once? Probably not.
Remove sections you do not use rather than hiding them. Hidden sections can still load their code. Keep the page short and the first screen simple.
Do not switch themes now. A new theme changes every template and can break your apps, tracking and checkout styling in a way you will not spot until real orders arrive. If the theme is the root problem, book a rebuild for January. Our web development service covers exactly that kind of work.
How do you tidy fonts?
Fonts cause two problems: slow text and jumping layouts. Shopify's guidance suggests self-hosting fonts on its CDN instead of calling an outside service, or using system fonts, which need no download at all. It also recommends fallback font settings that match your web font's size, so the page does not shift when the real font arrives.
Count how many font files you load. Two weights of one family is plenty for a store. Five weights across three families is too many.
Can your store handle the traffic?
Shopify hosts the platform, so you do not run servers. Still, your own setup can fail under a rush. Check the pieces you control:
- Apps that call outside servers on every page view, such as reviews and recommendation widgets.
- Pop-ups and banners that load late and push content down.
- Discount logic and bundle scripts that run on the cart page.
- Email and ad links, which should point to pages you have already tested.
Ask each app vendor whether it has handled a sale weekend before. A vendor that cannot answer is a risk. One slow widget can drag down a page that everything else got right, so take this step seriously.
What should you test at checkout?
Place a real test order on a phone, with a discount code, and again as a guest. Check the shipping options, the payment methods and the confirmation email. Run it on mobile data, not your office Wi-Fi.
Retest the cart page speed too. Cart and checkout are where slow scripts cost you the most, because the shopper has already decided to buy. If you are not sure what a proper setup should cost, our Shopify store cost calculator gives a rough range.
What should you not change the week of the sale?
Freeze the site around November 20. After that, change only what the admin is built for: prices, stock, banners and discount codes. Do not do any of the following:
- Install or update apps.
- Edit theme code or swap the theme.
- Change checkout settings or payment providers.
- Add new tracking scripts "just to see".
Every change in sale week is a bet with your best revenue days. Keep a copy of the working theme, so you can roll back in minutes if something breaks.
Before the freeze, run the page tests again and compare them to your first screenshots. You can also use our free speed and accessibility check for a quick second read. If the numbers are still short of the targets, pick the single slowest page and fix that one only. Trying to speed up a Shopify store in one big push is how mistakes slip in.
Frequently Asked Questions
How fast should a Shopify store load for Black Friday?
Google's targets are an LCP of 2.5 seconds or less, an INP of 200 milliseconds or less and a CLS of 0.1 or less, measured at the 75th percentile of real visits. Treat those as the minimum for sale week, not a stretch goal.
Do Shopify apps slow down my store?
Many do. Apps add scripts, stylesheets and requests to your pages. Shopify's own theme guidance tells developers to audit every script and remove or defer the ones that are not worth the cost. Test with the app on and off.
When should I stop making changes before Black Friday?
Aim for a freeze about a week before, so around November 20. That leaves time to catch a broken checkout or a shifted layout before traffic arrives. After the freeze, change only prices, stock and banners through the admin.
Is a high PageSpeed Insights score the same as a fast store?
No. The lab score is one simulated test. Real-user data from the field section of the same report matters more, because it shows what your shoppers on their phones actually experience.
Should I switch themes just before Black Friday?
Almost never. A theme swap changes every template and can break apps, tracking and checkout styling. Fix the slowest parts of your current theme now, and plan a rebuild for January.
Do the first three steps this week and you will have most of the gain. Spend what is left on one clean test order, then leave the store alone. A boring sale week is a good one.
