Web app performance is shaped by more than an interface. Content management systems, JavaScript, images, video, fonts, and page structure all affect what visitors download and how quickly a page responds. The 2024 Web Almanac examined 16.9 million websites and 83 TB of data, with research contributed by 91 volunteers. Its results provide a broad snapshot of the modern web, including the technical conditions relevant to media and streaming experiences.
Contents
- Scale and CMS adoption
- Core Web Vitals on desktop and mobile
- Performance by site popularity and page type
- JavaScript use across web apps
- Page weight and media payloads
- Fonts and delivery choices
Scale and CMS adoption
The Web Almanac’s 2024 edition analyzed 16.9 million websites and 83 TB of data. The project had 91 volunteer contributors. These figures describe the scale of the measurement effort rather than the size of the web-app market, but they matter when interpreting the percentages that follow: the results represent a large cross-section of websites, not a small product survey.
In June 2024, content management systems powered 51% of desktop websites and 51% of mobile websites. CMS adoption had risen on desktop from 46% in 2022 to 49% in 2023 and 51% in 2024. On mobile, adoption moved from 48% in 2022 to 49% in 2023 and 51% in 2024. The desktop and mobile rates therefore converged at 51% in June 2024.
The tracked URL population also changed substantially. Desktop HTTP Archive URLs grew from 5.4 million in July 2022 to 12.7 million in June 2024. The mobile tracked-URL count increased by 8.6 million in the 2023 dataset year. Because the Web Almanac reports these as changes in the measured datasets, they should not be read as a direct count of newly launched web apps.
Source: Web Almanac 2024 home page and CMS chapter.
Core Web Vitals on desktop and mobile
Core Web Vitals show a clear difference between desktop and mobile results. In 2024, 43% of mobile websites had good Core Web Vitals when measured with Interaction to Next Paint, or INP. The corresponding mobile result would have been 48% if First Input Delay, or FID, had been used instead. Desktop websites recorded 54% good Core Web Vitals in 2024 under either FID or INP.
The mobile trend can be read across the measurement years reported by the Web Almanac:
| Dataset year | Mobile good CWV with FID | Mobile good CWV with INP |
|---|---|---|
| 2022 | 39% | 31% |
| 2023 | 43% | 37% |
| 2024 | 48%* | 43% |
*The 2024 FID figure is the counterfactual result reported for measurement with FID instead of INP; INP is the 2024 measure used in the reported mobile result.
For a web app, this distinction is practical. A page can meet one interaction metric’s threshold while failing another, so comparisons across years need to identify the metric used. The 2024 mobile rate was 43% with INP, while the reported 2022 and 2023 INP rates were 31% and 37%, respectively. The same years’ FID results were 39% and 43%, followed by the 2024 counterfactual FID rate of 48%.
Source: Web Almanac 2024 Performance chapter.
Performance by site popularity and page type
Popularity did not guarantee a higher mobile Core Web Vitals result in the 2024 data. The 1,000 most popular mobile sites had a 40% good-CWV rate, below the 43% overall mobile rate. The corresponding desktop rate for the top 1,000 sites was 54%.
The Web Almanac also reported results for broader popularity bands:
| Site group | Mobile good CWV | Desktop good CWV |
|---|---|---|
| Top 1,000 | 40% | 54% |
| Top 10,000 | 33% | 46% |
| Top 100,000 | 31% | 43% |
| Top 1,000,000 | 36% | 48% |
These are 2024 rates, and the desktop result was higher than the mobile result in every listed group. The figures also show why a single “top sites” benchmark can hide meaningful differences between mobile and desktop delivery.
Page type influenced Largest Contentful Paint as well. In 2024, 63% of desktop home pages had good LCP, compared with 53% of mobile home pages. On secondary pages, the rates were higher: 82% for desktop and 72% for mobile. Home pages can carry more prominent branding, navigation, promotional modules, or media, while secondary pages may have a more focused content layout; the measured figures establish the difference but do not identify its cause.
Source: Web Almanac 2024 Performance chapter.
JavaScript use across web apps
JavaScript remained widespread in 2024. Legacy JavaScript was still shipped by 67% of mobile pages and 70% of desktop pages. The document.write method appeared on 12% of mobile pages and 13% of desktop pages.
Among named libraries and packages, jQuery appeared on 74% of mobile pages and 75% of desktop pages. core-js appeared on 41% of mobile pages and 42% of desktop pages. React appeared on 10% of both mobile and desktop pages.
| Technology or pattern | Mobile pages | Desktop pages |
|---|---|---|
| Legacy JavaScript | 67% | 70% |
| document.write | 12% | 13% |
| jQuery | 74% | 75% |
| core-js | 41% | 42% |
| React | 10% | 10% |
The close desktop-mobile values do not mean the delivered experience is identical. They indicate that the same broad technologies remained common across both page contexts. For media and streaming interfaces, the relevant engineering question is therefore not simply whether JavaScript is present, but how much code is sent, when it runs, and how it interacts with content that visitors expect to see or control quickly.
Source: Web Almanac 2024 JavaScript chapter.
Page weight and media payloads
The 2024 Web Almanac reported substantial JavaScript and image payloads on mobile home pages. The median mobile homepage loaded 558 KB of JavaScript and 900 KB of images. The median mobile inner page loaded 582 KB of JavaScript and 348 KB of images.
The contrast between home and inner pages is notable: the homepage carried the larger median image payload, while the inner page carried the larger median JavaScript payload. These are separate medians for separate resource types, so they should not be added together as a combined page-weight total.
The median page requested 24 JavaScript files on desktop and 22 JavaScript files on mobile in 2024. Request counts do not, by themselves, reveal total bytes or execution cost, but they show that a typical measured page assembled code from many separate files.
Media formats also varied widely at the upper end of desktop delivery. At the 90th percentile, video reached 8,614 KB on desktop pages. JPG images reached 274 KB, while AVIF images reached 45 KB. These are 90th-percentile resource values, not medians and not a claim that every page contained all three formats.
For a streaming-oriented web app, video is the largest of these reported 90th-percentile media values by a wide margin. That does not establish a user’s total streaming bandwidth, because the Web Almanac statistic describes page resources and does not quantify a full playback session. It does show why video delivery deserves separate attention from ordinary interface imagery.
Source: Web Almanac 2024 Page Weight chapter.
Fonts and delivery choices
Web fonts were used on around 87% of all websites in 2024. WOFF2 was used on 81% of desktop websites and 78% of mobile websites. Google Fonts appeared on 57% of desktop sites and 48% of mobile sites.
| Font statistic | Result |
|---|---|
| Websites using web fonts, all websites | Around 87% |
| Desktop websites using WOFF2 | 81% |
| Mobile websites using WOFF2 | 78% |
| Desktop sites using Google Fonts | 57% |
| Mobile sites using Google Fonts | 48% |
The source uses “around” for the all-website web-font figure, so it should be treated as an approximate rate. The desktop and mobile WOFF2 and Google Fonts figures are separate measurements for their respective site groups. Together, they describe a web in which typography is common, while the exact font technology and provider mix differs by device context.
For media and streaming products, fonts sit alongside scripts, images, and video in the loading path. The statistics do not quantify the performance effect of fonts on any particular app, but they identify a common resource category that belongs in a complete delivery inventory.
Source: Web Almanac 2024 Fonts chapter.