Unlock Faster Web Performance: The Data Behind Fastly's Edge Over Akamai

When a website onboards to Fastly, the expectation is a leap forward in performance. We analyzed popular websites that migrated from Akamai to Fastly and found significant, real-world performance gains. The data reveals a 57% faster Time to First Byte (TTFB) and a 17% faster Largest Contentful Paint (LCP) for migrating sites.

This analysis isn't based on synthetic lab tests. It uses Google's own Chrome User Experience Report (CrUX) data, reflecting how real users experience these websites daily. These numbers show a clear and consistent performance uplift for websites after they move to Fastly.

Methodology: How We Measured Real-World Performance

To ensure our analysis was accurate and fair, we established a strict and transparent methodology. Our goal was to isolate the impact of the CDN switch by studying a cohort of websites that made a clean migration from Akamai to Fastly.

We sourced our data from two open source public datasets: the Chrome UX Report (CrUX), which provides performance metrics from actual Chrome users, and the HTTP Archive, which tracks what technologies websites use. We identified the CDNs used by each origin from the Wappalyzer detections for all requests in the HTTP Archive with the origin’s hostname.

To be included in our analysis, a website had to meet the following criteria:

• A Clear Migration Path: The website must have been exclusively on Akamai for at least three consecutive months, optionally followed by a month where both Akamai and Fastly were detected, followed by a three-month period of being exclusively on Fastly for at least three consecutive months, for a total of at least 4 consecutive months using each CDN. This ensures we are comparing sustained performance on each platform and excluding any multi-CDN configurations.

• Popularity and Relevance: Each site had to be ranked within the top 1 million most popular websites globally in the month it was last detected using Akamai.

• Sufficient Data: Each site needed to have 75th percentile (p75) TTFB, First Contentful Paint (FCP), and LCP data available in the CrUX report for the relevant months. We used the BigQuery table chrome-ux-report.materialized.metrics_summary, which summarizes the metrics for all devices, effective connection types, and countries.

After applying these filters, our dataset consisted of popular websites that completed a clean migration from Akamai to Fastly between June 2024 and February 2025, using the data available from March 2024 and May 2025.

The Results: A Clear Performance Advantage

The data shows a distinct and immediate improvement in loading speed Web Vitals as soon as websites migrate to Fastly. We aligned each of the websites on the month they completed their migration to observe the trend. The results are striking.

For websites moving from Akamai to Fastly, we see a significant drop in page load times. Comparing the percentage difference in TTFB, FCP, and LCP from 3 months before Akamai’s last detected month to 3 months after, the median improvements across the websites are:

• Time to First Byte (TTFB): A 200 ms improvement, representing a 57% increase in speed. 82% of migrating websites saw a faster TTFB.

• Largest Contentful Paint (LCP): A 300 ms improvement, representing a 17% increase in speed. 89% of migrating websites saw a faster LCP.

• First Contentful Paint (FCP): A 200 ms improvement, representing an 18% increase in speed. 89% of migrating websites saw a faster FCP.

The chart below shows the performance of each website indexed to its own baseline on Akamai’s last seen month. A clear decrease in load times occurs during the migration period from -1 to +1 months relative to Akamai’s last seen date, and this improvement is sustained.

Looking at the raw median numbers each month tells the same story.

Why This Matters: The Real-World Impact of Speed

These metrics are more than just numbers; they represent real user experiences and have a direct impact on business outcomes.

• Faster TTFB: A lower TTFB means the client’s browser receives the root document earlier. This precedes all other page load events and directly leads to faster FCP and LCP.

• Faster LCP: LCP is a critical Google Core Web Vital metric that measures when the main content of a page becomes visible. A faster LCP is directly linked to higher user satisfaction and better SEO rankings. The 300 ms improvement we observed is substantial and can be the difference between a user staying on your site or leaving for a competitor.

Ultimately, a faster website translates to a better user experience, which can lead to higher conversion rates, improved brand perception, and a stronger bottom line. The data clearly shows that migrating to Fastly provides a significant and lasting performance advantage.