www.costco.ca speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 15:11 UTC. Grade A (91/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 53 ms 31%
- TCP connect 25 ms 15%
- Server wait 91 ms 54%
Measured on the connection that fetched the HTML. Every other request on the page waits for the end of this bar before it can start.
How this page compares
Every report published here is in this comparison, so it is a reference population of pages tested from one server - not a benchmark of the whole web.
What these numbers mean
- The server answered in 169 ms, which is fast: almost all of the wait is the page itself, not the host.
- The page transfers 867.6 KB over 26 request(s). Images files are 77% of it, so resize and recompress the largest images before anything else.
- The HTML itself arrives gzip-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- 77% of the weight comes from other hosts (analytics, fonts, embeds), which also means their slow day becomes your slow day.
- The largest element painted at 656 ms, inside the 2.5 s Google calls good.
- Layout shift is 0.477 (good is under 0.1): something without a reserved size is loading late - an image, an ad, or a font swap.
- The main thread was blocked for 1.30 s, so taps and scrolling wait while scripts run.
Fix first: Render-blocking resources - Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.
Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.
Browser render
The same URL loaded in a real browser, so these are the readings curl cannot produce. The grade above is still built from the server measurements.
Page weight by type
What the page is made of
Transfer size, compressed as sent. 26 request(s) in total, 867.6 KB across all of them.
Top issues
Render-blocking resources
high impact5 render-blocking resource(s) in the document head (2 script(s), 3 stylesheet(s)). The page cannot paint until each one arrives.
Fix: Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.
TLS certificate validity
high impactThe certificate for www.costco.ca has 20 day(s) left.
Fix: Renew automatically (certbot with a working renewal timer) and alert on the certificate, not on the renew command, so a silent failure is caught weeks before a browser warning.
Image delivery and format
medium impact0 image(s) over 200 KB and 1 large image(s) still served as JPEG or PNG.
Fix: Serve WebP or AVIF with a JPEG fallback, size images to the space they occupy, and lazy-load anything below the fold. Images are usually more than half of a slow page.
Third-party weight
medium impact1 third-party host(s) serve 670.5 KB of this page. Each one is another DNS lookup, TLS handshake and point of failure you do not control.
Fix: Self-host the libraries you can, drop the tags you cannot justify, and preconnect the ones you keep.
HTML document size
medium impactThe document transfers 197.1 KB. A bloated document delays every other request, because nothing else can start until it is parsed.
Fix: Paginate long listings, move repeated markup into a template, and stop inlining large data URIs into the HTML.
Waterfall
Slowest requests
Each bar is one request's own response time, scaled to the slowest. Assets were fetched in parallel, so the bars overlap in real time rather than stacking. first party third party
| Request | Type | Status | Time | Size |
|---|---|---|---|---|
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A84407a47-60a3-4519-af12-e9baa14f7ba5/as/26cweb0119-button-logos-th-en.avif?width=320 3rd party | images | 200 | 1.06 s | 13.5 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A2b6c7649-4074-4d4b-8db5-eaefcf4b39bc/as/26cweb0119-button-logos-warehouse-en.avif?width=320 3rd party | images | 200 | 1.06 s | 13.8 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3Abf095274-d308-4f51-b914-85e700a0affc/as/costco-logo-cabc.png?auto-format=false&width=320 3rd party | images | 200 | 1.05 s | 32.6 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A0a62d32b-15ef-4a5a-aa3a-03d5d43368c1/as/26cweb0119-button-logos-sunday-en.avif?width=320 3rd party | images | 200 | 1.05 s | 17.3 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:d510542d-2e4e-4233-801a-b2b71295bbba/as/26cweb0119-button-logos-D24-BMSM-en.avif?width=320 3rd party | images | 200 | 1.04 s | 8.2 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A3c9f71f4-3dac-430d-bd94-057f6d7a37d9/as/26cweb0119-button-logos-online-en.avif?width=320 3rd party | images | 200 | 1.04 s | 14.8 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3Ae569cfd9-528f-403a-9d0a-f0665f64997c/as/26cweb0119-button-logos-recommended-en.avif?width=320 3rd party | images | 200 | 1.03 s | 16.5 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A6be04a5a-7b2c-4995-999f-0e1da03689c1/as/26cweb0119-button-logos-CIBC-en.avif?width=320 3rd party | images | 200 | 1.03 s | 6.1 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:423f0e7d-8e64-4fee-af2f-3e220a04033e/as/26cweb0119-button-logos-senators-en.avif?width=320 3rd party | images | 200 | 1.02 s | 8.5 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A1de0eb53-d6a6-42d9-9ee6-2aa903fa54c8/as/26cweb0119-button-logos-lastchance-en.avif?width=320 3rd party | images | 200 | 1.02 s | 14.0 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A5c3249e8-4193-4894-9fee-693bdee23819/as/26cweb0119-button-logos-sameday-instacart-en.avif?width=320 3rd party | images | 200 | 996 ms | 20.5 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:932adb85-ef7a-424d-b0e1-0574f28619be/as/26cweb0119-button-logos-tickets-giftcards-en.avif?width=320 3rd party | images | 200 | 992 ms | 15.5 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:d510542d-2e4e-4233-801a-b2b71295bbba/as/26cweb0119-button-logos-D24-BMSM-en.avif 3rd party | images | 200 | 983 ms | 40.4 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3Abf095274-d308-4f51-b914-85e700a0affc/as/costco-logo-cabc.png?auto-format=false 3rd party | images | 200 | 960 ms | 117.4 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A0a62d32b-15ef-4a5a-aa3a-03d5d43368c1/as/26cweb0119-button-logos-sunday-en.avif 3rd party | images | 200 | 952 ms | 29.4 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3Ae569cfd9-528f-403a-9d0a-f0665f64997c/as/26cweb0119-button-logos-recommended-en.avif 3rd party | images | 200 | 942 ms | 27.4 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A08ae9075-e78e-4ad1-852b-d27feee3aa24/as/26cweb0119-button-logos-toppicks-en.avif 3rd party | images | 200 | 929 ms | 29.7 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A84407a47-60a3-4519-af12-e9baa14f7ba5/as/26cweb0119-button-logos-th-en.avif 3rd party | images | 200 | 917 ms | 21.1 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:423f0e7d-8e64-4fee-af2f-3e220a04033e/as/26cweb0119-button-logos-senators-en.avif 3rd party | images | 200 | 882 ms | 55.7 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A6be04a5a-7b2c-4995-999f-0e1da03689c1/as/26cweb0119-button-logos-CIBC-en.avif 3rd party | images | 200 | 882 ms | 28.2 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A3c9f71f4-3dac-430d-bd94-057f6d7a37d9/as/26cweb0119-button-logos-online-en.avif 3rd party | images | 200 | 880 ms | 27.0 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A2b6c7649-4074-4d4b-8db5-eaefcf4b39bc/as/26cweb0119-button-logos-warehouse-en.avif 3rd party | images | 200 | 872 ms | 22.0 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A5c3249e8-4193-4894-9fee-693bdee23819/as/26cweb0119-button-logos-sameday-instacart-en.avif 3rd party | images | 200 | 851 ms | 34.3 KB |
| https://gdx-assets.costco.com/adobe/assets/urn%3Aaaid%3Aaem%3A1de0eb53-d6a6-42d9-9ee6-2aa903fa54c8/as/26cweb0119-button-logos-lastchance-en.avif 3rd party | images | 200 | 850 ms | 24.9 KB |
| https://gdx-assets.costco.com/adobe/assets/urn:aaid:aem:932adb85-ef7a-424d-b0e1-0574f28619be/as/26cweb0119-button-logos-tickets-giftcards-en.avif 3rd party | images | 200 | 849 ms | 31.8 KB |
Report this page
Run this test on your own site
The same engine, free, with the screenshots and the fixes. No account needed.