As teams return from summer, many UK websites show improved performance, with more players optimising speed, stability, and interactivity.
Top 50: Wikipedia, Indeed, and Gov hold a rock-solid podium.
E-commerce: Ikea, Aldi, and John Lewis remain leaders, but only 29% of retail sites pass all CWV. Interactivity (INP) is still the weakest link, though progress is visible.
Media: The Guardian, BBC, and Sky Sports stay dominant. Stability (CLS) has dropped slightly, but 90% of sites load quickly (LCP green).
Travel: Love Holidays takes the lead over Transport for London in a close race. Still, it remains the worst-performing vertical: just 11% pass all CWV.
Takeaway: September confirms positive momentum after summer optimisations, but interactivity (INP) continues to be the critical challenge across all sectors.
It’s time to take a look at this month’s webperf rankings of the most visited sites in the UK.
We’re excited to unveil the new edition of our UK Speed Ranking : a snapshot of real-world mobile performance across four key sectors : Top 50 most visited, 🛒 E-commerce, 📰 Media and 🧳 Travel.
But before diving into the results, let’s remind ourselves why fast-loading websites are critical to online success.
📊 How the rankings are calculated ? The PX Index methodology.
As a reminder, the score obtained for the sites presented in this article is calculated using a methodology based on CrUX (Chrome User Experience Report) data. In order to give the best evaluation of each site’s mobile web performance, we based our calculations on the weighting of the Lighthouse score :
CrUX provides an overall assessment of the Core Web Vitals metrics for each site analysed. This metric is calculated by taking the 28-day rolling average of the 75 percentile performance throughout the month. The overall performance score is determined by a weighted average of the scores for each metric. This score, rated out of 100, is used in the rankings below (so it is not the PageSpeed score that is used in the rankings below). At Fasterize, we’ve made a clear choice: to rely exclusively on real-user data. That’s the foundation of the performance experience index (PX Index).
Why speed matters ?
Speed isn’t just technical : it’s strategic ! Studies show that website performance directly impacts user experience, conversion rates, and revenue. According to Google, 53% of mobile site visitors leave a page that takes longer than three seconds to load. For UK e-commerce sites, this statistic is particularly concerning given the intense market competition.
A Deloitte study reveals that a 0.1-second improvement in mobile site speed can increase conversion rates by 8.4% for retail sites. These figures highlight the importance of prioritizing loading speed to stay competitive.
Top 50 : Webperf ranking of the top 50 most visited websites in the United Kingdom
After the summer break, September marks the real “back-to-business” season. For many brands, it’s the moment to capitalise on optimisations launched during the quieter summer months and prepare for the high-stakes Q4 period. The question is: did those efforts hold up as traffic ramped back up?
🏆 TOP 3 LEADERS
The podium remains unchanged, showing remarkable consistency at the very top:
- Wikipedia (0) : still the gold standard with near-perfect metrics and an INP of just 93 ms
- Indeed (0) : smooth and highly interactive at 107 ms INP.
- Gov.uk (0) : continues to combine speed and reliability, the fastest loading site in the ranking (707 ms LCP).
🌟 NOTABLE IMPROVEMENTS
Several players stand out this month for their post-summer optimisations:
Mumsnet (+3 to #10) : shaved –44 ms on LCP, helping pages load faster.
Zoopla (+6 to #12) : strong gains across all metrics (–167 ms LCP, –10 ms INP, –0.03 CLS), making browsing more fluid.
Amazon (+7 to #13) : improved visual stability (CLS –0.02), a crucial enhancement for shopping journeys.
Rightmove (+4 to #24) : incremental but important improvements (–27 ms LCP, –10 ms INP, –0.02 CLS).
Vinted (+9 to #25) : one of the biggest winners this month, moving all Core Web Vitals into the green thanks to optimisations of –93 ms LCP, –30 ms INP, and –0.06 CLS.
Next (+2 to #36) : improved both loading and interactivity (–118 ms LCP, –57 ms INP), a positive sign for conversion-sensitive journeys.
These sites reflect ongoing efforts to improve web performance, which will likely continue to positively impact user experience and engagement. These improvements are the result of consistent efforts to optimize their systems, with particular attention paid to INP. It’s worth noting that having a good FID does not necessarily mean having a good INP! FID only measures the first interaction, whereas INP assesses interactivity throughout the entire browsing session. The efforts made by these players to improve their web performance metrics are not only beneficial for their rankings but are also crucial for providing a quality user experience, reducing bounce rates, and increasing engagement on their platforms.
📉 CHALLENGES IN THE RANKINGS
Other sites struggled to maintain summer performance levels:
Santander (–3 to #14) : slower LCP (+82 ms).
Marks & Spencer (–8 to #18) : regressions across both loading (+103 ms LCP) and interactivity (+11 ms INP), edging closer to orange thresholds.
Office (–4 to #19) : slight slowdown on LCP.
Express (–2 to #27) : small regressions across all three metrics.
Disney+ (–2 to #29) : heavier pages, with +203 ms on LCP.
BT (–6 to #30) : deteriorations on both LCP (+85 ms) and CLS (+0.05), pushing stability into orange.
Gumtree (–2 to #35) : layout shifts increased, moving CLS into orange.
Asda (–2 to #50) : a worrying drop with +609 ms on LCP, +66 ms on INP, and +0.10 on CLS, highlighting deeper technical debt.
📊 Averages for the sector:
🧪 Core Web Vitals Overview – Top 50 (September 2025)
✅ 36% of sites pass all three Core Web Vitals (up from 28% last month).
⏱ 70% meet the LCP benchmark — fast content delivery is improving.
🧭 52% (vs 46% last month) now pass the INP benchmark — a notable improvement, though still under half.
🔒 72% maintain a green CLS, reducing disruptive layout shifts.
Here are the e-commerce rankings, for which web performance is a business and SEO issue.
E-commerce : Webperf ranking of the top 30 most visited sites in the United Kingdom
Back-to-school and end-of-summer sales mean e-commerce traffic is heating up, and this month’s ranking shows that many retail teams used the quieter holiday weeks to improve their websites. Have they managed to maintain their web performance?
🏆 TOP 3
No shake-up at the very top:
- IKEA (0) : rock-solid, with LCP at 1,134 ms and INP at 135 ms.
- Aldi (0) : continues to deliver consistent loading and interaction performance.
- John Lewis (0) : holding steady, combining smooth interactivity with fast rendering.
🌟 NOTABLE IMPROVEMENTS
Some retailers clearly made good use of August to sharpen user experience:
PrettyLittleThing (+5 to #6) – the biggest mover, with a –286 ms LCP improvement and –44 ms INP, bringing it right into the green zone for interactivity.
Amazon (+2 to #7) – slight but valuable gains on LCP and CLS, reinforcing its stability during busy shopping journeys.
Vinted (+5 to #15) – a triple win: improvements on all Core Web Vitals, including CLS moving into the green, giving buyers a smoother browsing and listing experience.
Next (+4 to #21) – better responsiveness thanks to drops in both LCP and INP, which helps during high-conversion moments like checkout.
📉 CHALLENGES IN THE RANKINGS
Some big names, however, lost ground:
Marks & Spencer (–3 to #9) – regressions in both loading (+103 ms LCP) and interactivity (+11 ms INP).
Very (–2 to #10) – slightly slower, with +27 ms on LCP.
Shein (–4 to #25) – one of the largest drops, with a +221 ms LCP, +29 ms INP, and CLS edging dangerously close to orange.
📊 Averages for the sector:
🧪 Core Web Vitals Overview – E-commerce (September 2025)
The sector shows strong progress compared to August, with interactivity (INP) finally seeing real gains:
✅ 29% of sites pass all three Core Web Vitals thresholds (vs 13% in August).
⏱ 71% now have a green LCP (vs 65%), ensuring main content loads quickly.
🧭 35% meet the INP benchmark (vs 19%) — proof that optimisation efforts are paying off.
🔒 71% show stable layouts with a green CLS (vs 68%), reducing visual shifts during browsing and checkout.
While some players like Vinted and M&S are making visible progress, the sector overall still struggles with INP. For e-commerce, where every millisecond can impact conversion, improving interactivity should be the next big priority.
Media : Webperf ranking of the top 30 most visited sites in the United Kingdom
In August, media sites continued to battle for performance leadership. With news consumption surging during both holidays and back-to-work season, stability and responsiveness remain critical to keeping readers engaged.
🏆 TOP 3 LEADERS
- The Guardian (0): holding the crown with an INP of 118 ms and consistently strong performance.
- BBC (0): reliable as ever, balancing fast loading (LCP 903 ms) with stability.
- Sky Sports (0): strong INP of 125 ms ensures smooth interactions for sports fans.
Some outlets clearly optimised during the summer period:
The Times (+3 to #7) : cut 129 ms on LCP, improving article load speed.
Independent (+2 to #11) : shaved 20 ms off INP.
GB News (+4 to #16) : achieved a 101 ms faster LCP and a –0.04 CLS drop, reducing layout shifts.
Sporting Life (+2 to #26) : significant improvement with –294 ms on LCP.
📉 CHALLENGES IN THE RANKINGS
Others saw regressions that risk disrupting user experience:
The Scottish Sun (–2 to #9) : slower loading, with +177 ms LCP.
Yahoo (–2 to #10) : degraded across metrics (+111 ms LCP, +14 ms INP).
Hello Magazine (–2 to #13) : experienced +48 ms LCP and +9 ms INP, slipping in responsiveness.
Birmingham Live (–7 to #23) : the steepest drop, with slower LCP (+92 ms), worse INP (+12 ms), and CLS slipping into orange (–0.05).
📊 Averages for the sector:
Core Web Vitals Overview – Media (September 2025)
❌ Only 30% of media sites meet all three Core Web Vitals — proving that even mature players still face challenges.
⏱ 87% (vs 90% last month) deliver fast loading (green LCP).
🧭 Just 36% (vs 40%) meet the INP benchmark, showing that sluggish interactivity remains the sector’s weak point.
🔒 77% (down from 90%) maintain stable layouts (green CLS) — a worrying dip in page stability that could frustrate readers.
Travel : Webperf ranking of the top 30 most visited sites in the United Kingdom
As travellers return from holidays and plan their next trips, performance in the travel sector remains under the spotlight. September shows tight competition at the top, but also highlights that this vertical is still the slowest overall when it comes to user experience.
Let’s see how the top travel platforms performed in September.
🏆 TOP 3 LEADERS
A reshuffle at the very top, decided by fine margins:
Love Holidays (+1 to #1) takes the lead with small but decisive gains (–7 ms LCP, –12 ms INP) and a flawless CLS of 0.00.
Transport for London (–1 to #2) improved its LCP, but a +0.01 increase in CLS meant it lost the crown.
Pitchup (0, #3) holds steady, though its INP at 202 ms keeps it in the orange zone for interactivity.
Even among leaders, differences come down to a handful of milliseconds !
🌟 NOTABLE IMPROVEMENTS
Trip Advisor (+3 to #4) : stronger performance with –33 ms on LCP and a small improvement in stability (–0.02 CLS), pushing it closer to the podium.
📉 CHALLENGES IN THE RANKINGS
Vrbo (–3 to #9) : saw regressions across all Core Web Vitals, with +169 ms on LCP, +10 ms INP, and +0.01 CLS. A triple setback at a time when users expect faster search and booking.
📊 Averages for the sector:
🧪 Core Web Vitals Overview – Travel (September 2025)
Despite some progress, travel remains the worst-performing vertical in the UK Speed Ranking:
✅ Only 11% of sites pass all three Core Web Vitals thresholds.
⏱ 52% (vs 48% last month) meet the LCP benchmark — still leaving nearly half too slow to load key content.
🧭 Just 22% achieve green INP, underlining persistent weaknesses in interactivity and responsiveness.
🔒 48% (vs 44% last month) now have stable layouts (green CLS) — a slight improvement, but instability is still common.
In such a competitive market, standing out through your website’s performance is essential. Fast loading times not only improve user experience but also increase conversion rates and generate more revenue. This monthly ranking is a valuable tool to measure and enhance your site’s performance, allowing you to position yourself against competitors and identify areas for improvement.
We encourage all UK e-commerce leaders to invest in optimizing their site speed and to explore how tools and services like those we offer at Fasterize can help unlock faster, smoother, and more profitable digital experiences to stay competitive. Stay tuned for the next edition to see how your competitors evolve — or how you can overtake them.
Where does your site stand in the UK Webperf Ranking?
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