www.colorado.edu speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 13:14 UTC. Grade C (77/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 72 ms 23%
- TCP connect 46 ms 15%
- Server wait 193 ms 62%
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 first byte arrived in 311 ms. That is workable, and the cheapest win left is caching or a warmer connection.
- The page transfers 2.04 MB over 26 request(s). Images files are 58% 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.
- The largest element painted at 900 ms, inside the 2.5 s Google calls good.
- Layout stayed still (CLS 0.043), so nothing jumps under the reader's cursor.
- The main thread was blocked for 346 ms, so taps and scrolling wait while scripts run.
Fix first: Compress text responses - Turn on brotli (preferred) or gzip for text/css, javascript and text/html in the web server. This is the cheapest win available on almost any site.
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, 2.04 MB across all of them.
Top issues
Compress text responses
high impact1 text response(s) of 10 KB or more are sent uncompressed, and the document itself is not compressed. That is 42.9 KB of compressible text.
Fix: Turn on brotli (preferred) or gzip for text/css, javascript and text/html in the web server. This is the cheapest win available on almost any site.
Image delivery and format
high impact3 image(s) over 200 KB and 5 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 impact9 render-blocking resource(s) in the document head (3 script(s), 6 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 2.04 MB across 26 request(s), with the document itself at 17.9 KB.
Fix: Work through the heaviest assets first: images, then fonts, then third-party scripts.
JavaScript weight
medium impact1 JavaScript file(s) over 200 KB: all.min.js (632.4 KB)
Fix: Split routes, remove unused dependencies, and prefer a two-file build (one pinned library, one application bundle) over many small ones.
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://cdn.colorado.edu/static/brand-assets/live/images/cu-boulder-logo-text-white.svg 3rd party | images | 0 | 2.12 s | 0 B |
| https://cdn.colorado.edu/static/brand-assets/live/images/search-white.svg 3rd party | images | 0 | 2.08 s | 0 B |
| https://calendar.colorado.edu/widget/view?schools=ucboulder&types=114987&days=90&num=10&experience=all&container=localist-widget--2&template=card 3rd party | javascript | 200 | 1.15 s | 42.9 KB |
| https://www.colorado.edu/sites/default/files/styles/section_background/public/2026-10/homepage-herro-2021_Aerial429GA-BW.jpg?itok=LqmQzw_L | images | 200 | 1.04 s | 385.7 KB |
| https://www.colorado.edu/sites/default/files/styles/section_background/public/2026-08/2025_Health_and_Wellness_Fair28GA%20-%20Edited.jpg?itok=5xMHg1Jm | images | 200 | 1.03 s | 271.8 KB |
| https://www.colorado.edu/sites/default/files/styles/section_background/public/2025-08/divider-gray-top.png?itok=Y5viNb9r | images | 200 | 1.02 s | 1.2 KB |
| https://www.colorado.edu/sites/default/files/styles/section_background/public/2025-08/divider-white-top.png?itok=8j-jfq6- | images | 200 | 990 ms | 1.2 KB |
| https://www.colorado.edu/sites/default/files/css/css_wsHnpqR6FKFo1_q1sDSTSL0bRzZJp8ZgOfiQpIUEDME.css?delta=3&language=en&theme=boulder_base&include=eJx9kmtuxCAMhC8Ub44UGXAIXV6yTbu5fdmwq1ZK2p98M5btMaa06IgXg0JzCp5RaRHdI8lkfmvNGjCM2YFBPku2ZKWs4Dm4s0qfXROwGCm7q_K1FCWGRLkBkw8lnz0-FoPxzBN5HJUmFnu_MuR2TeHYFJTRBb1sWtHTmQoh2w1MefyppeKuhhXqSfUI9v93laB0ZIpWIeS1vBI6O5Ue-lrcFqbZcasYb_iBjymRCzivIfbKm8V6rFiRsZ-5bvL2_pBby7WZGGQjN8kuSml-dpp6p8X0CaRHVZeIe2kq40-8Kbzo4bWYapMl09dwjTc830O_99G08FJj8yHL_AYwwDiMfAOnRwJv | css | 200 | 987 ms | 10.0 KB |
| https://www.colorado.edu/sites/default/files/styles/large_image_style/public/2025-08/academics.jpg?itok=aAC5If-N | images | 200 | 982 ms | 156.3 KB |
| https://www.colorado.edu/sites/default/files/css/css_EJ46bycJYka5fjLZYhnGpi8GUkTEqi-Qx0IedUpLB-A.css?delta=1&language=en&theme=boulder_base&include=eJx9kmtuxCAMhC8Ub44UGXAIXV6yTbu5fdmwq1ZK2p98M5btMaa06IgXg0JzCp5RaRHdI8lkfmvNGjCM2YFBPku2ZKWs4Dm4s0qfXROwGCm7q_K1FCWGRLkBkw8lnz0-FoPxzBN5HJUmFnu_MuR2TeHYFJTRBb1sWtHTmQoh2w1MefyppeKuhhXqSfUI9v93laB0ZIpWIeS1vBI6O5Ue-lrcFqbZcasYb_iBjymRCzivIfbKm8V6rFiRsZ-5bvL2_pBby7WZGGQjN8kuSml-dpp6p8X0CaRHVZeIe2kq40-8Kbzo4bWYapMl09dwjTc830O_99G08FJj8yHL_AYwwDiMfAOnRwJv | css | 200 | 975 ms | 61.8 KB |
| https://www.colorado.edu/sites/default/files/js/js_VlqLmW9VLt32dgkTrk4lHFvDi4ww4QBL8BNqA5qNqDo.js?scope=footer&delta=1&language=en&theme=boulder_base&include=eJx1jUEOwjAMBD9E6I07F74R2a0VQp24ih1Bf09pAIkCF0s7O1qjVB6oeASlrvboAgsC73DLEwVYTq4OWfrxl5DrN1WC0p8dyu1vl2RYHgaRwOQNQheWs817uMDtE6bdMuJRxNQKTJ5hlmq6Tr-pe9LV7SFNVX2ma7Nado_c-pGGaFL8xDXErN0LuAac2szUXDvHMvgJis2eIxYokbQ7SbbjlVQSHe5tUIZt | javascript | 200 | 969 ms | 53.7 KB |
| https://www.colorado.edu/sites/default/files/css/css_hcNU0xqELT7t6REIllfXfCjYsOdEr_0GPBuKEn_RuWo.css?delta=0&language=en&theme=boulder_base&include=eJx9kmtuxCAMhC8Ub44UGXAIXV6yTbu5fdmwq1ZK2p98M5btMaa06IgXg0JzCp5RaRHdI8lkfmvNGjCM2YFBPku2ZKWs4Dm4s0qfXROwGCm7q_K1FCWGRLkBkw8lnz0-FoPxzBN5HJUmFnu_MuR2TeHYFJTRBb1sWtHTmQoh2w1MefyppeKuhhXqSfUI9v93laB0ZIpWIeS1vBI6O5Ue-lrcFqbZcasYb_iBjymRCzivIfbKm8V6rFiRsZ-5bvL2_pBby7WZGGQjN8kuSml-dpp6p8X0CaRHVZeIe2kq40-8Kbzo4bWYapMl09dwjTc830O_99G08FJj8yHL_AYwwDiMfAOnRwJv | css | 200 | 968 ms | 5.8 KB |
| https://www.colorado.edu/core/assets/vendor/jquery/jquery.min.js?v=4.0.0 | javascript | 200 | 962 ms | 31.4 KB |
| https://www.colorado.edu/modules/contrib/google_tag/js/gtm.js?tmx5br | javascript | 200 | 948 ms | 576 B |
| https://www.colorado.edu/sites/default/files/css/css_UNC1LQ_EayMmmq36aMzP0mOUbUU6cqRCq3q85qq0T_Y.css?delta=4&language=en&theme=boulder_base&include=eJx9kmtuxCAMhC8Ub44UGXAIXV6yTbu5fdmwq1ZK2p98M5btMaa06IgXg0JzCp5RaRHdI8lkfmvNGjCM2YFBPku2ZKWs4Dm4s0qfXROwGCm7q_K1FCWGRLkBkw8lnz0-FoPxzBN5HJUmFnu_MuR2TeHYFJTRBb1sWtHTmQoh2w1MefyppeKuhhXqSfUI9v93laB0ZIpWIeS1vBI6O5Ue-lrcFqbZcasYb_iBjymRCzivIfbKm8V6rFiRsZ-5bvL2_pBby7WZGGQjN8kuSml-dpp6p8X0CaRHVZeIe2kq40-8Kbzo4bWYapMl09dwjTc830O_99G08FJj8yHL_AYwwDiMfAOnRwJv | css | 200 | 942 ms | 1.4 KB |
| https://www.colorado.edu/themes/custom/boulder_base/favicon.png | images | 200 | 936 ms | 1.6 KB |
| https://www.colorado.edu/sites/default/files/css/css_zOe1ZaCs6E5g9C3cx2FXaor4Gb4_1_o72k5vZF5-GYM.css?delta=5&language=en&theme=boulder_base&include=eJx9kmtuxCAMhC8Ub44UGXAIXV6yTbu5fdmwq1ZK2p98M5btMaa06IgXg0JzCp5RaRHdI8lkfmvNGjCM2YFBPku2ZKWs4Dm4s0qfXROwGCm7q_K1FCWGRLkBkw8lnz0-FoPxzBN5HJUmFnu_MuR2TeHYFJTRBb1sWtHTmQoh2w1MefyppeKuhhXqSfUI9v93laB0ZIpWIeS1vBI6O5Ue-lrcFqbZcasYb_iBjymRCzivIfbKm8V6rFiRsZ-5bvL2_pBby7WZGGQjN8kuSml-dpp6p8X0CaRHVZeIe2kq40-8Kbzo4bWYapMl09dwjTc830O_99G08FJj8yHL_AYwwDiMfAOnRwJv | css | 200 | 930 ms | 8.2 KB |
| https://www.colorado.edu/modules/custom/ucb_third_party_libraries/js/FontAwesome/all.min.js?v=1 | javascript | 200 | 921 ms | 632.4 KB |
| https://www.colorado.edu/sites/default/files/styles/large_image_style/public/2025-08/Linden_Lab.CC06.JPG?itok=bH6SyuWR | images | 200 | 921 ms | 116.3 KB |
| https://fonts.googleapis.com/css2?family=Roboto+Condensed:wght@400;700&family=Roboto:wght@400;500;700&display=swap 3rd party | css | 200 | 921 ms | 324 B |
| https://www.googletagmanager.com/ns.html?id=GTM-M3DX2QP 3rd party | html | 200 | 908 ms | 409 B |
| https://www.colorado.edu/modules/contrib/google_tag/js/gtag.js?tmx5br | javascript | 200 | 905 ms | 652 B |
| https://www.colorado.edu/sites/default/files/js/js_HyloNXaiQiOVHuhtvmt0M9r3sINMbjeUzjmUaNyWfYc.js?scope=header&delta=0&language=en&theme=boulder_base&include=eJx1jUEOwjAMBD9E6I07F74R2a0VQp24ih1Bf09pAIkCF0s7O1qjVB6oeASlrvboAgsC73DLEwVYTq4OWfrxl5DrN1WC0p8dyu1vl2RYHgaRwOQNQheWs817uMDtE6bdMuJRxNQKTJ5hlmq6Tr-pe9LV7SFNVX2ma7Nado_c-pGGaFL8xDXErN0LuAac2szUXDvHMvgJis2eIxYokbQ7SbbjlVQSHe5tUIZt | javascript | 200 | 905 ms | 248 B |
| https://www.colorado.edu/sites/default/files/styles/large_image_style/public/2025-08/2025_CUB_Commencement87GA-crop.jpg?itok=yD94X9jG | images | 200 | 896 ms | 286.8 KB |
| https://cdn.colorado.edu/static/brand-assets/live/images/150-beboulder.svg 3rd party | images | 0 | 802 ms | 0 B |
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