The ecommerce CRO knowledge base
Plain-English guides to the checks behind your Store Health Score: what each one means, why it matters, and how to fix it.
Full audit checklists
Checklist
Shopify store audit checklist: every check that affects sales
A Shopify store audit checks the pages a shopper sees against the things that cost sales: speed, the path to checkout, trust, tracking and how search engines read the sto...
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WooCommerce store audit checklist: every check that affects sales
A WooCommerce store audit checks the pages a shopper sees against the things that cost sales: speed, the path to checkout, trust, tracking and how search engines read the...
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10 guides
Cumulative Layout Shift (CLS): why your store jumps and how to stop it
Cumulative Layout Shift (CLS) adds up how far visible elements move unexpectedly while a page loads. Google counts 0.1 or lower as good and over 0.25 as poor. The classic case is a shopper about to tap a button when a banner loads above it and pushes it down.
Google mobile performance score: what it means and how to raise it
The mobile performance score is Google's summary of how quickly your page loads and responds on a mid-range phone. Lighthouse produces a 0 to 100 number from several timings, and Google also assesses real visitors as fast, average or slow. This check uses the real-visitor verdict when Google has it.
Interaction to Next Paint (INP): what a good score is and how to improve it
Interaction to Next Paint (INP) measures the delay between a shopper tapping, clicking or typing and the page visibly responding. Google counts 200 milliseconds or less as good and over 500 milliseconds as poor. It replaced First Input Delay as a Core Web Vital in March 2024.
Largest Contentful Paint (LCP): how to get under 2.5 seconds
Largest Contentful Paint (LCP) is the time until the biggest visible element, usually the hero image or main product photo, finishes rendering. Google counts 2.5 seconds or less as good and anything over 4 seconds as poor. It is the closest single number to "when does the page look ready".
Page weight: how big should an ecommerce home page be?
Page weight is the total data a page downloads. This audit flags a home page that transfers more than 2MB. Images are usually the largest share, followed by JavaScript from themes and apps. Weight matters most on mobile data, where every megabyte adds seconds.
Third-party scripts on ecommerce sites: how much is too much?
Third-party scripts are code loaded from domains other than your store: analytics, chat, reviews, ads, popups. Each is useful on its own. Together they can outweigh your own site and slow every tap. This check flags stores where their combined weight is more than a reasonable share.
Broken images, scripts and stylesheets: how to find failed requests
A broken subresource is a file the page asks for and does not get: an image, script or stylesheet that returns a 404 or another error. Each failed request wastes time, and a missing script can quietly switch off a feature such as search or a size chart.
Slow product and collection pages: how to compare templates against the rest of your site
Template speed compares your product and collection pages against a plain content page such as About or Contact. When the content page is fast and the product page is slow, the problem sits in the product template or the apps that load on it, not in your hosting or theme base.
Time to First Byte (TTFB): how fast your server should answer
Time to First Byte (TTFB) is the time between a browser asking for a page and receiving the first byte of the response. Google treats 800 milliseconds or less as good. Everything else on the page waits for it, so a slow TTFB delays every later metric.
WebP and AVIF images: why modern formats make product pages faster
Modern image formats such as WebP and AVIF compress photos much better than JPEG or PNG at the same visible quality. Serving them cuts image weight, which is the largest part of most ecommerce pages. This check looks at whether your images arrive in a modern format.
Conversion and UX
60 guides
Add to cart buttons: what makes shoppers find and use them
The add-to-cart button is the one action a product page exists for. This check confirms that the page offers a visible, working add-to-cart control that a shopper can find without hunting, on desktop and on a phone.
Guest checkout: why forcing an account loses orders
Guest checkout lets a shopper pay without creating an account. Research by the Baymard Institute has consistently listed forced account creation among the top reasons for abandoned checkouts. This check confirms that guests can complete a purchase.
Machine-readable price and availability on product pages
A product page should state its price, currency and availability in the markup, not only visually. Search engines, shopping feeds and price tools read that data. If the page shows a price but the code does not, those systems cannot use it.
Price, shipping and delivery clarity on product pages
Shoppers want to know the total cost and the arrival date before they commit. Price, shipping cost and delivery expectations should be legible on the product page without hunting. This check looks for them.
Product name, price and buy button on the first phone screen
On a phone, the first screen of a product page should show the product name, the price and the buy button, or at least the first two plus a clear way to the third. If the shopper has to scroll to find the price, you have made a decision for them. This check tests that on a typical phone screen.
Search autocomplete: suggest products and terms as shoppers type
Search autocomplete shows suggested terms and products as a shopper types. It saves typing, corrects spelling and shows that the store has what they want. This check types a term from a real product name and reads what the search offers.
Sticky headers: keep navigation, search and cart in reach while scrolling
A sticky header stays on screen as the shopper scrolls, keeping the menu, search and cart within reach. On long category and product pages it saves repeated scrolling. This check scrolls your page and tests whether the header stays reachable.
The viewport meta tag: make your store render properly on phones
The viewport meta tag tells a phone to render the page at the width of the screen. Without it, mobile browsers pretend the screen is about 980 pixels wide and shrink the page to fit, which makes text tiny and buttons impossible to tap. Every modern theme includes it, so a failure here usually means a custom or broken template.
Value proposition above the fold: say what you sell and why buy here
A value proposition is the short statement of what you sell and why a shopper should buy it from you. The first screen of the home page should make it clear in seconds, to a visitor who has never heard of the store. This check looks for that clarity.
Add to cart or quick view on category product cards
Product cards on a category page can carry an add-to-cart or quick-view button. Shoppers who know what they want add without opening the page, and others preview details in place. This check looks for the button on the cards.
Alt text for product images: how to write it for shoppers and search
Alt text is a short written description of an image. Screen readers read it to people who cannot see the photo, and search engines use it to understand what the picture shows. This check looks at whether the product images on your page carry alt text.
Ask for email or phone first at checkout
The first field in checkout should be email or phone. Once you have it, you can follow up if the shopper leaves, and the form feels short from the start. This check reads the first field of checkout.
Breadcrumbs on product pages: help shoppers back to the category
A breadcrumb trail shows the path from the home page to the current product, such as Home, Shirts, Linen shirt. It tells a shopper where they are and gives a quick route back to the category. This check looks for a breadcrumb trail on the product page.
Buy button text: say plainly what the button does
The text on the main product button should say what happens when it is pressed: Add to cart, Buy now, Pre-order. Clever or vague labels make shoppers wonder whether they are committing to a purchase. This check reads the button text.
Change quantities in place in the cart
A shopper who wants two of an item instead of one should be able to change it in the cart. A stepper beside each line does it without going back to the product. This check looks for a quantity control on cart items.
Combined filters on category pages: size, colour, price and more
On a category page, shoppers often want to narrow by more than one attribute: size and colour and price. Filters that can be combined let them do it. This check looks for a category page whose filters can be applied together.
Default sort order on category pages: why best sellers first
Most shoppers never change the sort order, so the default decides what they see. Listing best sellers first puts proven products where attention is highest. An arbitrary or oldest-first default shows whatever happened to be added first. This check reads the default order.
Empty cart pages: point shoppers to something to buy
An empty cart page that says only "Your cart is empty" is a dead end. Links to popular categories, bestsellers or the last collection viewed turn it into a way back. This check opens the empty cart and looks for what it offers.
Free shipping progress in the mini-cart: how much more to spend
If your store offers free shipping over a threshold, the mini-cart is the best place to show how close the shopper is. A line such as "You are $12 away from free shipping" nudges them to add an item. This check looks for that message.
Hide the coupon field behind a link in the cart
An always-open coupon box invites shoppers without a code to leave and search for one, and some do not return. Putting the field behind a "Have a code?" link keeps it available for those who have one. This check looks at how the coupon field is shown in the cart.
Highlight the current section in the main navigation
When a shopper is inside a category, the matching item in the main navigation should look different: underlined, bold or coloured. It answers "where am I?" without a thought. This check looks for an active state in the menu.
How many product photos do you need? Showing products from several angles
Online shoppers cannot pick the product up, so the gallery stands in. Showing several angles, detail shots and context gives them a way to judge it. This check looks for more than one image on the product page.
Let shoppers ask a question on the product page: chat, phone or form
A shopper with an unanswered question rarely buys. A direct way to ask on the product page, such as chat, a phone number or an ask-a-question form, turns doubt into a conversation. This check looks for one.
Let shoppers remove items from the cart easily
A shopper who added the wrong item needs a clear way to remove it. A visible remove link or icon next to each line item, with a quantity control, is the standard. This check looks for it on the cart.
Mention your return policy in the cart
A short note about returns in the cart, such as "Free returns within 30 days" with a link to the policy, answers the doubt that stops many purchases. This check looks for it on the cart page.
Mini-cart links: offer both a way to the cart and to checkout
A mini-cart is the slide-out or dropdown that appears after adding an item. It should link to both the full cart and the checkout. Some shoppers want to review, others want to pay. This check looks for both links.
Mobile tap targets: how big should buttons and links be?
A tap target is any button or link a shopper presses with a finger. Fingers are far less precise than a mouse, so targets need to be big enough and far enough apart. Google suggests at least around 48 pixels across with some spacing. This check looks at your main actions.
Numeric keyboard for number fields at checkout
Fields that expect digits, such as phone, card number and postal code, should open a number pad on a phone. The right input type or inputmode attribute does it. This check looks at numeric fields in checkout.
Product images that build trust: size, quality and what shoppers look for
Photos are the nearest thing a shopper has to holding the product. Large, sharp, consistent images signal a careful seller, and blurry or tiny ones signal the opposite. This check looks for enough imagery to judge the product.
Product title length: write titles that show fully in Google results
Google cuts page titles that are too long, so a title that carries the product name, a long modifier and the store name may show only half. Shorter titles with the important words first display fully. This check looks at your product title tag.
Search box hints: show example queries, not just the word Search
A search box that only says "Search" gives no clue about what works. A hint such as Search for jackets, boots or gift cards shows the shopper what to type. This check looks at the placeholder or hint text.
Show a way to get help at checkout
A shopper who hits a problem at checkout needs a way to ask for help without leaving. A phone number, chat or contact link on the checkout page serves that. This check looks for one.
Show an estimated delivery date in the cart
When will it arrive? is the question shoppers ask last before paying. A delivery date or range in the cart answers it at the point of decision. This check looks for a delivery estimate on the cart page.
Show checkout progress: which step the shopper is on
A progress indicator, such as Information, Shipping, Payment, shows where the shopper is and how much is left. It makes a multi-step checkout feel short. This check looks for it on a checkout that has more than one step.
Show free shipping progress in the cart
If you offer free shipping above an amount, the cart should show how close the shopper is. "Add $12 more for free shipping" is a prompt that often turns into an extra item. This check looks for that message in the cart.
Site search for ecommerce: why shoppers who search buy more
Visitors who use site search tend to know what they want and are closer to buying. A visible search box lets them go straight to it. This check confirms that shoppers can search the catalogue from the page.
Size charts on product pages: reduce returns and doubt
For clothing and shoes, size is the biggest source of doubt and returns. A size chart linked next to the size options answers it at the moment of choice. This check looks for a size chart link near the size selector.
Sorting on category pages: let shoppers order products their way
A sort control lets a shopper reorder a category by price, popularity, newest or rating. It is one of the quickest ways to cut a long list down to what they care about. This check looks for sorting on the category page.
Tell shoppers how tax is handled in the cart
The cart should say how tax is handled: included in the price, or added at checkout. A single line removes the question and the surprise. This check looks for tax wording in the cart.
Title tags and meta descriptions for store pages: length, content and what to avoid
The title tag and meta description are the headline and summary that search results show for your page. A clear title decides whether a shopper clicks, and a good description supports it. This check confirms that your key pages have both, and that they are usable.
What a mini-cart should show: item, price, total and count
The mini-cart confirms the add-to-cart worked. It should show the item with a picture, its price, the cart total and how many items are in it. This check reads those elements after an item is added.
What belongs in an ecommerce header: logo, cart and a clear menu
The header appears on every page, so it is the most reused part of the store. It should carry a logo that links to the home page, a cart link and a menu that is short enough to scan. This check looks for those three elements.
Zoom on product photos: let shoppers look closer
Shoppers cannot inspect a product in person, so zoom is their magnifying glass. The main product photo should open larger or zoom when tapped or hovered. This check looks for that behaviour.
A continue shopping link in the cart: keep shoppers in the store
A continue shopping link in the cart takes the shopper back to the catalogue to add more items. Without it, the only way out is the back button, and many shoppers who wanted one more item leave instead. This check looks for the link on the cart page.
A lock icon on the checkout button
A small padlock beside the checkout button signals that the next step is secure. It is a tiny cue that reassures shoppers about to enter payment details. This check looks for a lock icon on the cart checkout button.
Back to top links on long home pages
A back to top link or button returns the shopper to the header after a long scroll. On a long home page with many sections it saves effort, especially on phones. This check looks for one on the home page.
Email keyboard on checkout: set the right input type for phones
When a shopper taps the email field at checkout on a phone, the keyboard should show the @ symbol and dot. That happens when the field is set to type email. This check looks at the email field on your checkout.
Favicons and home-screen icons: small details that signal a real store
A favicon is the small icon in a browser tab, bookmark and search result. A home-screen icon is what appears when a shopper adds your store to their phone. A store without them shows a blank globe, which reads as unfinished.
Keep legal and policy links out of the main navigation
The main navigation should help shoppers find products. Legal and policy links such as terms of service and privacy belong in the footer. This check flags a main menu that carries them.
Keep shoppers on the product page: avoid outgoing links in content
A product page should keep shoppers on the store. Links in the description that lead to other websites invite them to leave. This check looks for outgoing links in the product content.
Label sold-out products clearly on category pages
If sold-out products appear in a category, they should be labelled as sold out on the card. A shopper who clicks through to find the item unavailable has wasted a step and may leave. This check looks for those labels.
Let returning customers log in at checkout
Returning customers save time when they can sign in at checkout and have their details filled. A visible log in link alongside the guest option serves them. This check looks for it.
One H1 per page: heading structure for ecommerce pages
A page should have one top-level heading, the H1, that names what the page is. Below it, H2 and H3 headings divide sections. Themes sometimes use H1 for the logo or for several sections, which blurs the structure. This check looks for exactly one H1 on each key page.
Password recovery at checkout for returning customers
Returning customers who try to sign in at checkout and cannot remember their password need a way to reset it right there. A visible forgot-password link keeps them in the purchase. This check looks for it near the checkout sign-in.
Quantity selectors: use a stepper or number field, not a dropdown
The quantity control on a product page should let a shopper enter any sensible number. A plus and minus stepper or a number field does that quickly. A dropdown with a fixed list forces extra taps and limits choice. This check looks at the control type.
Save for later and wishlists in the cart
Save for later, or a wishlist, lets a shopper move an item out of the cart without losing it. It suits considered purchases where people compare, wait for payday or ask someone else. This check looks for the option in the cart.
Say what size the model is wearing
On apparel pages, a line such as "The model is 1.80 m and wears size M" gives shoppers a reference. They compare themselves with the model and decide their size more confidently. This check looks for it on the product page.
Second photo on hover for category product cards
A second photo that appears when a shopper hovers a product card shows another angle without a click. On desktop it makes browsing richer, and it costs one extra image per product. This check looks for the feature on category cards.
Show how many products a category lists
Showing the number of products in a category, such as 48 products, gives shoppers a sense of scale. They know whether to scroll, filter or search. This check looks for a product count on category pages.
Wishlists on ecommerce stores: when they help and when they do not
A wishlist lets a shopper save products to look at again, share, or buy later. It suits stores selling considered or gift purchases. This check looks for a wishlist feature on the home page.
Trust and policies
7 guides
HTTPS for online stores: why shoppers and Google expect it
HTTPS encrypts the connection between a shopper and your store. Without it, browsers label the page "Not secure", and anything typed into a form can be read on the way. This check confirms that your store loads over HTTPS and requests nothing insecurely.
Mixed content warnings: how to find and fix insecure resources
Mixed content is a page served over HTTPS that still loads some files, such as images, scripts or fonts, over plain HTTP. Browsers may block these files or show a security warning, which can break features and cost shoppers' trust at checkout.
Express checkout and instalment options: why offering more payment methods helps
Express checkout means wallet buttons such as Apple Pay, Google Pay and Shop Pay, which fill in payment and shipping from stored details. Instalment options let a shopper split a purchase. This check looks for evidence that your store offers at least some of them.
Product reviews and ratings: how to show social proof on product pages
Reviews are the most persuasive content on a product page, because they come from people who bought. This check looks for star ratings or written reviews on the product page, and for review data in the page markup that search engines can read.
Return, shipping, privacy and terms pages: what every store needs
Policy pages are the pages shoppers read before they trust a store with money: returns, shipping, privacy and terms. This check looks for links to all four from the pages a shopper actually visits, usually the footer.
Contact information for online stores: how shoppers expect to reach you
Shoppers want to know a real business sits behind the store. A visible way to make contact, such as an email address, a contact page, a phone number or live chat, is one of the quickest trust signals. This check looks for at least one working route.
What to put in an ecommerce footer: policy links, social profiles and trust cues
The footer is where shoppers look for the things they need before paying: policy links, contact details, social profiles and payment badges. This check looks for the essentials, so a shopper who scrolls to the bottom finds reassurance and not an empty strip.
Tracking and tech
5 guides
Google Analytics 4 not collecting data: how to check and fix it
Google Analytics 4 (GA4) is the analytics property most stores use to see traffic, sources and sales. This check confirms that GA4 is installed on your store and actually sending data, because an install that exists on paper but sends nothing leaves you without numbers.
Meta Pixel not firing PageView: how to find out and fix it
A Meta Pixel that is on the page is not the same as a Meta Pixel that works. The pixel must send a PageView event to Meta on each load. If it loads and sends nothing, your ads optimise against no data. This check looks for the PageView request itself.
Duplicate Google Analytics 4 tracking: how to find double counting
Duplicate GA4 tracking means more than one Google Analytics 4 property is collecting data from the same page. Sessions, orders and revenue can then be counted twice in one property, or split across two, and the numbers never match what the payment system shows.
Duplicate tags and pixels: how to find tags loading twice
A duplicate tag is the same pixel or tag manager container loaded more than once on a page. Events fire twice, conversions are counted double and the page downloads the same script again. This check looks for more than one container or pixel per vendor.
Cookie consent banners for online stores: do you need one?
A cookie consent mechanism asks visitors to accept or refuse tracking cookies before analytics and advertising tags run. Stores that sell to people in the European Union, the United Kingdom and a growing list of other places usually need one. This check looks for it.
Store discovery
19 guides
Is your store online? How to check it loads for every visitor
The most basic check is whether your store loads for an ordinary visitor. A page that returns an error, hangs, or shows a bot wall to normal browsers cannot sell anything. The audit opens your address in a real browser and confirms that a real page appears.
Is your store indexable? Noindex tags, canonical URLs and how to check them
Indexability means search engines are allowed to put a page in their results. A stray noindex tag, a blocked path or a canonical URL that points elsewhere can remove a page from search without any visible sign. This check confirms that your key pages can be indexed and declare a canonical address.
Gzip and Brotli compression: how to check pages are sent compressed
Compression shrinks text files such as HTML, CSS and JavaScript before they travel over the network. Gzip and Brotli typically cut their size by well over half. Almost every hosted platform does this automatically, and a self-hosted store that skips it sends far more data than needed.
Product structured data: how to add price and availability for Google
Product structured data is code that describes a product in a form search engines can read: name, image, price, currency and whether it is in stock. Without a valid offer, Google has less to show about your product in search and shopping results.
robots.txt for ecommerce stores: what to allow, block and link
The robots.txt file sits at the root of your site and tells search engine crawlers which paths they may visit. A good one lets them reach products and collections, keeps them out of carts and accounts, and points to your sitemap. This check looks for all three.
XML sitemaps for online stores: how to check and submit yours
An XML sitemap is a file that lists the pages you want search engines to find: products, collections, content pages. It does not guarantee indexing, but it helps crawlers discover new and updated pages. This check confirms that your store has one.
Content delivery networks for ecommerce: how a CDN speeds up your store
A content delivery network, or CDN, keeps copies of your pages and files on servers around the world and serves each visitor from a nearby one. Distance adds delay, so a CDN cuts load time for shoppers far from your host. Hosted platforms include one; self-hosted stores often need to add it.
Custom 404 pages for stores: return a real 404 and help shoppers back in
When a visitor requests a page that does not exist, your store should return a genuine 404 status and show a helpful page with search and links back into the catalogue. A page that says "not found" but returns a 200 status is called a soft 404, and it confuses search engines.
Internal links on product pages: how related products help shoppers and search
Internal links on a product page, such as related products and links back to the collection, give shoppers a next step and give search engines a path through your catalogue. This check looks for those links.
Keep cart, checkout and account pages out of search results
Cart, checkout and account pages are for shoppers who already have a session. They should not appear in search results. Keeping them out stops thin or private pages from competing with your products and wasting crawl effort.
Lazy loading images: when it helps and when it slows the page
Lazy loading tells the browser to load an image only when the shopper is about to see it. It saves data for pictures far down the page. It should be used for images below the first screen and never for the main hero or product photo, which should load first.
Linking social profiles from your store: where and why
Linking your store to its social profiles gives shoppers a way to check that real people run the business, and gives search engines a way to connect the profiles with your brand. This check looks for links to social profiles on the home page, usually in the footer.
Open Graph tags: how your store looks when a link is shared
When someone pastes your store link into a message or social post, the preview card comes from Open Graph tags in the page. They set the title, description and image. This check confirms that those tags exist, so shared links look like a store and not a bare address.
Product image file names: why IMG_4821.jpg costs you search visibility
Search engines read image file names as a clue to what a photo shows. A file called linen-shirt-navy-front.jpg says something. IMG_4821.jpg says nothing. This check looks at the file names of your product images.
Product page headings: how to organise content with H2 and H3 subheadings
Subheadings break a product page into sections a shopper can scan: description, materials, sizing, shipping, reviews. They also tell search engines what each part is about. This check looks for a sensible heading structure below the main title on the product page.
Product URL structure: short, readable addresses without tracking parameters
A good product address is short, readable and describes the product, such as /products/linen-shirt. Long strings of numbers, session IDs and tracking parameters make addresses harder to share and can create several URLs for one page. This check looks at the structure of your product addresses.
Redirect chains and loops: how the http address should reach your store
A redirect chain is a sequence of redirects before the final page, such as http to https to www to a language path. Each hop adds a delay, and chains can break when one link in them changes. A loop never ends. The http address should reach your store in a single redirect.
Using the product name in the URL, title and heading
A product page is clearest when the product name appears in its address, its title tag and its main heading. These three places are the strongest on-page signals of what a page is about. This check looks at whether they agree.
www vs non-www: how to make your store open at one address
A store can often be reached at both www.example.com and example.com. If both load without redirecting, search engines may treat them as two copies and split the ranking between them. One address should redirect to the other, permanently.
Know which guides apply to your store.
The audit runs 200+ checks and links each failing one to its guide.