Website performance checklist

Use this checklist to audit your site's performance, whether you are doing a routine check or preparing for a redesign or marketing campaign.

How to use this checklist

Some items are things you can do yourself. Others are for your web team. The checklist is divided into sections so you can hand off the right parts to the right people.

Beginner items are things most non-technical team members can do. Developer items require technical access or knowledge.

Measurement (do this first)

• Test your homepage with PageSpeed Insights Beginner Visit pagespeed.web.dev and test your home page. Note the Core Web Vitals status (green/amber/red) and the overall score.

• Test your most important landing pages Beginner Your homepage may score well, but key product or service pages may have different images and scripts. Test at least three pages.

• Check your Core Web Vitals in Google Search Console Developer If you have Search Console set up, open the Core Web Vitals report. It is built from real visitor data over the last 28 days, not a simulated test, and it groups similar pages together rather than scoring each one.

Images

• No photo is over 1 MB, and most are under 200 KB Beginner Check your media library (in WordPress, go to Media). Our target is under 200 KB for most photos; anything over 1 MB is almost certainly slowing your site and should be compressed or replaced.

• Images are sized to their display dimensions Beginner A thumbnail does not need to be a 4,000-pixel-wide original. Resize images before uploading.

• Images are in WebP or compressed JPEG format Developer An image optimization plugin or manual conversion handles this. WebP is the best choice for most images: Google's figure is 25–34% smaller than a comparable JPEG, and it works on every modern browser.

• Images have descriptive alt text Beginner Alt text helps accessibility and SEO. See Alt text explained.

• Lazy loading is enabled Developer WordPress has added lazy loading to images by itself since version 5.5, so this is usually already on. Confirm a plugin or theme has not switched it off.

Caching

• Caching is active Developer Either a caching plugin (WP Rocket, WP-Optimize, LiteSpeed Cache, etc.) or your host's built-in caching should be running. Never two page-cache plugins at once: they both need the same WordPress drop-in file, so they cannot coexist. If your host already caches pages, a plugin on top is often unnecessary — verify with your web team.

• Cache clears correctly after updates Developer When you publish a change, the cached version should update. Test this: publish a small change and check if it appears for a logged-out visitor within a few minutes.

Hosting

• Time to First Byte (TTFB) is 800 ms or less Developer PageSpeed Insights reports TTFB alongside your Core Web Vitals, as an experimental metric. Google's guide is that most sites should aim for 0.8 seconds or less; anything over 1.8 seconds counts as poor and usually points at hosting. TTFB is not itself a Core Web Vital, so treat it as a clue rather than a target in its own right.

• You are on managed WordPress hosting (if on WordPress) Beginner Ask us if you are not sure. Managed WordPress hosts usually bundle caching and a CDN as standard: Flywheel, for example, lists FlyCache and a Fastly-powered CDN among its platform features.

• A CDN is active Developer Ask your host or development team, and check what your plan actually includes rather than assuming.

Scripts and plugins

• Review all installed plugins Developer Delete any plugin that is no longer used. Deactivating one stops it running on your pages, but its files stay on the server, and WordPress's own hardening guide says to delete what you are not using.

• Identify third-party scripts Developer List all external scripts running on the site (Google Analytics, chat widgets, social share buttons, pixels, heatmaps). Remove any that are no longer needed.

• No duplicate functionality Developer Two caching plugins, two SEO plugins, two contact form plugins — any duplication wastes resources and creates conflict risk.

Fonts

• Use a maximum of two typefaces Beginner More than two font families is usually unnecessary and slows font loading.

• Load only the font weights you use Developer A Google Fonts embed should load only the weights the design actually uses — often just two or three — not every available weight "just in case."

Mobile

• Test on a real mid-range Android device Beginner Your iPhone may not reflect the experience of budget phone users. Borrow a mid-range Android (or ask us to test) to see what average visitors experience.

• Mobile Core Web Vitals are green Beginner Check the Mobile tab in PageSpeed Insights as well as Desktop. Google indexes and ranks from your site's mobile version, and Core Web Vitals are one of the signals its ranking systems use. Those three are measured from real visitors, not from the simulated test, so treat the overall score as a rough guide and the Core Web Vitals as the numbers that count.

Ongoing habits

• Compress images before every upload Beginner Make this a habit. See Images & page speed.

• Check performance after major updates Beginner After a redesign, a new plugin installation, or a major content change, re-run PageSpeed Insights.

• Run a performance review every six months Beginner Sites accumulate weight over time. A periodic check catches problems before they become serious.

Common questions

Do I need to complete the whole checklist to see improvement?

No. The items at the top (images, caching, hosting) will get you the most improvement fastest. Work through the rest over time.

Can I share this checklist with my developer?

Yes — share this page link. The Developer-tagged items are specifically for your technical team to action.

Related guides

• How to measure your site's speed
• Images & page speed
• Caching explained
• Performance: realistic expectations
• Website health checklist
• My site is slow

Learn more

• PageSpeed Insights
• Learn Performance — web.dev
• Time to First Byte (TTFB) — web.dev