Total
10.15 MB
123 requests
100% of total size
https://www.amazon.co.uk/
See the website health and performance test results for https://www.amazon.co.uk/, including status code, load speed, SSL, WHOIS, DNS, console logs, Chrome UX Report, resource sizes, and Pagespeed findings.
Tested on 25 May 2026 21:47:04.
Up
- HTTP status 200
- Response time 663 ms
- Document load time 0 ms
- Full page load time 0 ms
- Document size 0 B
- Full page size 0 B
58/100
- Mobile score 58
- Desktop score 82
Observer's Performance Suggestions
Priority actions Observer identified from this test to improve speed, reliability, and user experience.
|
Mobile score is 24 points lower than desktop
Warning
High
Desktop scores 82/100 but mobile only 58/100. Optimize for mobile CPU, network and viewport — most real-world traffic is mobile. Read more |
|
Domain transfer lock is not enabled
Warning
Medium
The domain has neither clientTransferProhibited nor serverTransferProhibited status, which means it could be transferred to another registrar without additional safeguards. Enable transfer lock through your registrar to prevent unauthorized transfers. Read more |
|
Desktop performance needs improvement (82/100)
Warning
Medium
Score is below 90. Tackle the highest-impact audits to push into the green. Read more |
|
Mobile performance needs improvement (58/100)
Warning
Medium
Score is below 90. Tackle the highest-impact audits to push into the green. Read more |
|
High Total Blocking Time (214 ms)
Warning
Medium
Long JavaScript tasks block the main thread, making the page feel unresponsive. Split long tasks, defer non-critical scripts, and reduce third-party JavaScript. Read more |
|
Slow Speed Index (4.6 s)
Warning
Medium
The page takes too long to visually complete. Optimize critical rendering path, reduce render-blocking resources, and serve visible content first. Read more |
|
Fewer than 75% of users have a good Cumulative Layout Shift
Warning
Medium
Only 72% of real-user samples fall in the "good" bucket for Cumulative Layout Shift. Read more |
|
LCP image resource load is slow
Warning
Medium
The p75 LCP image resource load delay is 923 ms. Optimize image delivery with a CDN, caching, or smaller formats to reduce load time. Read more |
|
LCP image TTFB is slow
Warning
Medium
The p75 LCP image time-to-first-byte is 517 ms. Use a faster origin server, CDN, or preconnect hints to reduce initial response time. Read more |
|
Reduce unused JavaScript
Info
Medium
Strip JavaScript that the page does not use to reduce parse and download time. Read more |
Only the top 10 of 11 suggestions are shown in the public test. To see all recommendations and track every change on your website, register now.
Did you know?
Observer tracks these signals every day and alerts you the moment something important changes. Register now.
16 Jan 2027
230 days left
Whois
- Registrar
- Amazon.com, Inc. [Tag = AMAZON-COM]
SSL
- SSL available
- Yes
- SSL status
- valid
- Issuer
- C=US,O=Amazon,CN=Amazon RSA 2048 M04
- Subject
- CN=www.amazon.co.uk
- TLS version
- TLSv1.3
- Self-signed
- No
- Valid until
- 16 Jan 2027
DNS Records
Current DNS records returned for this domain at the time of the test.
- DNS status
- resolved
- 18.165.62.8
- 2600:9000:2467:2600:15:c9dc:596:d01
- 2600:9000:2467:3a00:15:c9dc:596:d01
- 2600:9000:2467:3c00:15:c9dc:596:d01
- 2600:9000:2467:7200:15:c9dc:596:d01
- 2600:9000:2467:d000:15:c9dc:596:d01
- 2600:9000:2467:d600:15:c9dc:596:d01
- 2600:9000:2467:ec00:15:c9dc:596:d01
- 2600:9000:2467:f800:15:c9dc:596:d01
- tp.bfbdc3ca1-frontier.amazon.co.uk
- amazon-smtp.amazon.com
- ns-1256.awsdns-29.org
- ns-1689.awsdns-19.co.uk
- ns-430.awsdns-53.com
- ns-558.awsdns-05.net
- MS=ms12314789
- MS=ms45048758
- ZOOM_verify_3Ko9ExAfA3lpXCh9QPR15B
- adobe-idp-site-verification=b6bcd3e5aaffc63607c8bf75744d9a0d1febc50dd7f389428e2ae476c9ba8814
- atlassian-domain-verification=ZT4AapXgobCpXIWoNcd7gtMjZyOUdr4EDFMnFUWrqqqgdaQVbDvoGpRaIwj/tgPH
- autodesk-domain-verification=9bCtBBfcSX131DnPfMqz
- box-domain-verification=ffea95cd0e0d61c302198367155b07e74fd534fa1d867662dc9bf9969b6f535d
- canva-site-verification=FSBzoxF2qUazDMl38A7ESw
- cisco-ci-domain-verification=2d2409c79bc50c72151404f511810173a1d51f0721e3f7090b2dcda39aa3a7f1
- cisco-ci-domain-verification=7efb722588ec060653fa68cb28b9206879d3abc91ffab361fd37cedf44bebfe7
- docker-verification=b640e25c-e841-4505-9fa7-160d642dca15
- facebook-domain-verification=s683te1vv3i7f7c7fbq4ps45yxkt6l
- google-gws-recovery-domain-verification=68063740
- google-gws-recovery-domain-verification=70440345
- google-site-verification=6t-dcIVf42O-EoNSfBL2kWoN33DKL83FokcApn7S2us
- google-site-verification=g_bTkCPIdl9j6VSKKAfoQl12ZHKgvAk0X3lwzUqu1fM
- google-site-verification=lVzfHahZqH9Fqj0vAsjH_J5ee3Zewa0CMgaj6Tqixxg
- liveramp-site-verification=jZJKgMEQ_1mdjMhKj02iqNACZ-NJHRWhCEQdQ_OuCMo
- sending_domain1003771=503f4d4816370d2e5c2f06087d972e8c76d700ddf473e8976f7e72f6e4940089
- sending_domain1003771=6d479c2e18f1858893f5c32bf9908c9b085932a84541ee85c8d873ed7f24b83f
- sending_domain229492=2712d9f9a3a3adcb0285c54b3ea3cb718a69130fc0ddfa34cc74dcefe396f31a
- sending_domain229492=bc19ba09b42dbc12618ad5755af2606329fa3a20ca423a330779fb5cfa0e71ce
- sending_domain608861=81f88310c30e2fee703ed330cd919efe1f70cb299998749208d381707f584c8c
- sending_domain608861=d7e8b07477dfc929c3eaf73f3d87d52b876cb7ceaaf93c6213319abf8120b52e
- spf2.0/pra include:amazon.com -all
- stripe-verification=8E217BE0FF12B50596BD78EEA3F81E62C6C7A2AC78FBD46DAD95B7D21BA2F8BF
- v=spf1 include:amazon.com -all
Resource Summary
Transfer size share of the tested page split by resource type.
Media
7.82 MB
4 requests
77% of total size
Font
727.96 KB
21 requests
7.0% of total size
Script
598.24 KB
31 requests
5.8% of total size
Image
541.77 KB
40 requests
5.2% of total size
Document
380.43 KB
2 requests
3.7% of total size
Stylesheet
91.02 KB
11 requests
0.9% of total size
Other
51.57 KB
14 requests
0.5% of total size
Third-party
10.15 MB
123 requests
100% of total size
Total
6.71 MB
190 requests
100% of total size
Media
2.67 MB
2 requests
40% of total size
Image
2.55 MB
125 requests
38% of total size
Font
724.07 KB
21 requests
11% of total size
Script
504.27 KB
18 requests
7.3% of total size
Document
150.82 KB
2 requests
2.2% of total size
Stylesheet
134.21 KB
10 requests
2.0% of total size
Other
10.68 KB
12 requests
0.2% of total size
Third-party
6.71 MB
190 requests
100% of total size
Core Web Vitals
Key performance signals from Lighthouse, with color-coded status for what is healthy and what still needs work.
The server starts responding quickly.
Users wait too long before any content appears.
Main visible content takes too long to appear.
Some layout movement still affects the experience.
Visual progress is slower than recommended.
Script execution still delays interactivity.
Potential input delay is high.
Users wait too long before the page responds.
TTFB
603 ms
FCP
4.23 s
LCP
8.17 s
TTI
8.41 s
The server starts responding quickly.
First visible content appears quickly.
Main visible content loads within the recommended range.
The layout stays visually stable while loading.
Visible content fills the page quickly.
Main thread blocking stays in a healthy range.
Potential input delay may still feel sluggish.
The page becomes interactive quickly.
TTFB
165 ms
FCP
712 ms
LCP
2.33 s
TTI
2.38 s
Loading Filmstrip
Visual loading progress from the Lighthouse run, shown in time order.
Google Pagespeed Insights
Switch between desktop and mobile Lighthouse results to review the latest performance findings for this page.
Mobile
58
Desktop
82
Audit Details
| Audit | Insight | Impact |
|---|---|---|
| Network dependency tree |
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load. |
Open |
| Layout shift culprits |
Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads. |
Open |
| Render-blocking requests |
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
|
Est savings of 1,920 ms |
| Minimize main-thread work |
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work |
4.5 s |
| LCP request discovery |
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading |
Open |
| Avoid large layout shifts |
These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS
|
7 layout shifts found |
| LCP breakdown |
Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays. |
Open |
| Reduce unused JavaScript |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
|
Est savings of 273 KiB |
| Reduce JavaScript execution time |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
|
1.9 s |
| Font display |
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
|
Est savings of 50 ms |
| Largest Contentful Paint |
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn more about the Largest Contentful Paint metric |
8.2 s |
| First Contentful Paint |
First Contentful Paint marks the time at which the first text or image is painted. Learn more about the First Contentful Paint metric. |
4.2 s |
| Max Potential First Input Delay |
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric. |
300 ms |
| Time to Interactive |
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric. |
8.4 s |
| Reduce unused CSS |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
|
Est savings of 193 KiB |
| Use efficient cache lifetimes |
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
|
Est savings of 3 KiB |
| Legacy JavaScript |
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
|
Est savings of 6 KiB |
| Image elements do not have explicit `width` and `height` |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
|
Open |
| Avoid enormous network payloads |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
|
Total size was 10,398 KiB |
| Improve image delivery |
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
|
Est savings of 206 KiB |
| Speed Index |
Speed Index shows how quickly the contents of a page are visibly populated. Learn more about the Speed Index metric. |
4.6 s |
| Total Blocking Time |
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more about the Total Blocking Time metric. |
210 ms |
| Cumulative Layout Shift |
Cumulative Layout Shift measures the movement of visible elements within the viewport. Learn more about the Cumulative Layout Shift metric. |
0.1 |
Audit Details
| Audit | Insight | Impact |
|---|---|---|
| Forced reflow |
A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.
|
Open |
| Reduce JavaScript execution time |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
|
1.3 s |
| Reduce unused JavaScript |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
|
Est savings of 246 KiB |
| Network dependency tree |
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load. |
Open |
| LCP request discovery |
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading |
Open |
| LCP breakdown |
Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays. |
Open |
| Render-blocking requests |
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
|
Est savings of 310 ms |
| Improve image delivery |
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
|
Est savings of 849 KiB |
| Minimize main-thread work |
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work |
3.7 s |
| Image elements do not have explicit `width` and `height` |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
|
Open |
| Minify JavaScript |
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
|
Est savings of 12 KiB |
| Avoid enormous network payloads |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
|
Total size was 6,871 KiB |
| Reduce unused CSS |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
|
Est savings of 145 KiB |
| Font display |
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
|
Est savings of 20 ms |
| Use efficient cache lifetimes |
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
|
Est savings of 3 KiB |
| Legacy JavaScript |
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
|
Est savings of 13 KiB |
| Largest Contentful Paint |
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn more about the Largest Contentful Paint metric |
2.3 s |
| Speed Index |
Speed Index shows how quickly the contents of a page are visibly populated. Learn more about the Speed Index metric. |
1.8 s |
| Max Potential First Input Delay |
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric. |
170 ms |
| Total Blocking Time |
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more about the Total Blocking Time metric. |
150 ms |
Chrome UX Report
Real-user experience shares from recent Chrome visits to this website.
Origin: https://www.amazon.co.uk
Mobile 56.1%
Desktop 38.8%
Tablet 5.1%
| Metric | User experience share | 75th percentile |
|---|---|---|
| LCP |
Good 87.8%
Needs improvement 8.2%
Poor 4.0%
|
1.72 s |
| INP |
Good 79.9%
Needs improvement 13.2%
Poor 6.9%
|
161 ms |
| CLS |
Good 72.1%
Needs improvement 14.6%
Poor 13.2%
|
0.11 |
| FCP |
Good 89.6%
Needs improvement 6.9%
Poor 3.6%
|
1.04 s |
| TTFB |
Good 79.7%
Needs improvement 14.2%
Poor 6.1%
|
659 ms |
Get daily monitoring and instant alerts with Observer.
Register Observer to keep testing your website automatically and react faster when something breaks.
Try Observer Discover