www.scientificamerican.com speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 12:57 UTC. Grade C (74/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 52 ms 29%
- TCP connect 20 ms 11%
- Server wait 110 ms 60%
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 182 ms, which is fast: almost all of the wait is the page itself, not the host.
- The page transfers 6.79 MB over 26 request(s). Images files are 99% of it, so resize and recompress the largest images before anything else.
- The HTML itself arrives br-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- 95% 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 408 ms, inside the 2.5 s Google calls good.
- The main thread was blocked for 99 ms in total, which is not enough to feel.
Fix first: Image delivery and format - 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.
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.
Screenshot
What the page looks like
Loaded in headless Chromium on this server. Click an image to open it full size.
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, 6.79 MB across all of them.
Top issues
Image delivery and format
high impact2 image(s) over 200 KB and 2 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.
Render-blocking resources
high impact4 render-blocking resource(s) in the document head (1 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.
Total page weight
high impactThe page transfers 6.79 MB across 26 request(s), with the document itself at 54.0 KB.
Fix: Work through the heaviest assets first: images, then fonts, then third-party scripts.
Third-party weight
medium impact1 third-party host(s) serve 6.48 MB 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.
Avoid extra redirects
medium impact1 redirect hop(s) before the page load started, each one a full round trip before the first byte.
Fix: Link to the canonical URL (and make sure http, the apex domain and www all point at it) so no visitor pays a redirect first.
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://static.scientificamerican.com/dam/asset/43030498-6a8a-4e7e-ade9-1abf11916843/face-attention-mapping.png?m=1792445232.127&w=550 3rd party | images | 200 | 1.13 s | 48.6 KB |
| https://static.scientificamerican.com/dam/asset/ee914aee-5897-4c72-8e2c-40e698cc064d/shutterstock_160874294.jpg?m=1792500342.931&w=300 3rd party | images | 200 | 1.10 s | 18.3 KB |
| https://static.scientificamerican.com/dam/asset/2bd4d77f-19a4-4719-b523-dfa0a046f934/indonesia-flood.jpg?m=1791989296.871&w=300 3rd party | images | 200 | 1.10 s | 22.9 KB |
| https://static.scientificamerican.com/dam/asset/80b8bc19-ba1e-463b-a934-6de23ef320ca/saw1126Szal01_Online.jpg?m=1791157879.138&w=300 3rd party | images | 200 | 1.09 s | 19.6 KB |
| https://static.scientificamerican.com/dam/asset/16f4139d-d39a-45ea-ba4a-35f1a0cc66b0/saw1126-Industry1.jpg?m=1790608663.159&w=300 3rd party | images | 200 | 1.08 s | 47.9 KB |
| https://static.scientificamerican.com/dam/asset/cdccb3d4-2f8b-4edb-95e0-78a66666c767/Chinese-Terracotta-Warriors.jpeg?m=1791980725.693&w=300 3rd party | images | 200 | 1.08 s | 16.0 KB |
| https://static.scientificamerican.com/dam/asset/2c46abd5-8095-4c6f-a02c-7f8dadad362e/saw1126SOW.jpg?m=1791308920.564&w=300 3rd party | images | 200 | 1.08 s | 32.1 KB |
| https://static.scientificamerican.com/dam/asset/22580373-927b-440c-b68b-52cd94c55bc5/ICEYE-X36_COSMOS-2612.gif?m=1792494922.589&w=300 3rd party | images | 200 | 1.06 s | 5.74 MB |
| https://static.scientificamerican.com/dam/asset/3f2bd140-c61b-4407-9ff3-bac2c050a340/flu-virus.jpg?m=1792166751.717&w=300 3rd party | images | 200 | 1.06 s | 27.1 KB |
| https://static.scientificamerican.com/dam/asset/11c2eb7a-99d8-42cb-a3d5-5d44897705ef/openai-fluid.jpeg?m=1791912843.397&w=300 3rd party | images | 200 | 1.06 s | 14.2 KB |
| https://static.scientificamerican.com/dam/asset/ed025c64-e1d0-471a-9a65-b3459a5902fb/emotions.jpg?m=1792427313.952&w=300 3rd party | images | 200 | 1.01 s | 18.3 KB |
| https://static.scientificamerican.com/dam/asset/98719ffc-d401-4742-9916-dfb6cf3068e4/saw1126-FromTheEditor-IssueCover.jpg?m=1790608387.326&w=300 3rd party | images | 200 | 1.01 s | 34.4 KB |
| https://static.scientificamerican.com/dam/asset/1238bcf9-445c-46b5-8082-9e969a0e84ae/saw1126Jaco01.jpg?m=1790531976.207&w=300 3rd party | images | 200 | 1.01 s | 28.6 KB |
| https://static.scientificamerican.com/dam/asset/a391bf71-3871-4e82-b082-6ba3b8c36bec/leap-hour-announcement.jpg?m=1792077851.037&w=300 3rd party | images | 200 | 999 ms | 5.4 KB |
| https://static.scientificamerican.com/dam/asset/d9410eeb-2788-4f49-8f34-fc93e355d169/2610_SQ_MON_OCT_19.png?m=1792175484.98&w=550 3rd party | images | 200 | 995 ms | 80.0 KB |
| https://www.scientificamerican.com/static/assets/subCTA-Bj95gvdx.jpg | images | 200 | 990 ms | 204.8 KB |
| https://static.scientificamerican.com/dam/asset/6b0e8aee-eced-4303-8bea-4a7267ec6ae8/saw1126Adva-skullroots.jpg?m=1790615840.35&w=300 3rd party | images | 200 | 984 ms | 35.3 KB |
| https://static.scientificamerican.com/dam/m/3da926a3ccf413bb/original/mathPuzzles-opener.jpg?m=1723038172.878&w=300 3rd party | images | 200 | 984 ms | 16.7 KB |
| https://static.scientificamerican.com/dam/asset/a399c3e7-0823-4560-a593-363622cbf282/sa1126Cvr.jpg?m=1790460258.029&w=512&h=677 3rd party | images | 200 | 976 ms | 108.2 KB |
| https://www.scientificamerican.com/static/assets/today_in_science_mockup-Bp-Vt1F7.png | images | 200 | 976 ms | 60.1 KB |
| https://static.scientificamerican.com/dam/asset/74e78a67-3d94-46a2-aa86-1d981561c73d/saw1126Stra01.jpg?m=1790692636.492&w=300 3rd party | images | 200 | 975 ms | 65.9 KB |
| https://static.scientificamerican.com/dam/asset/776e2202-11d4-41f1-9645-ae9b530acb33/theranos.png?m=1792175868.041&w=300 3rd party | images | 200 | 975 ms | 43.5 KB |
| https://static.scientificamerican.com/dam/asset/24e19f0e-9f5f-4f3a-ab04-73b3aa196bea/saw126Adva-bees.jpg?m=1790615898.637&w=300 3rd party | images | 200 | 975 ms | 32.9 KB |
| https://static.scientificamerican.com/dam/asset/2a3b0f04-e239-4802-9d2c-110a9aff63ad/saw1126Luhn_lead.jpg?m=1791578350.184&w=300 3rd party | images | 200 | 975 ms | 31.9 KB |
| https://static.scientificamerican.com/dam/asset/2dcfc085-1eed-4d53-a225-e4e79c05f1fb/shutterstock_2466463165-WEB.jpg?m=1792106020.16&w=300 3rd party | images | 200 | 975 ms | 8.0 KB |
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