Changelog
The CrUX dataset on BigQuery is updated on the second Tuesday of every month. Each release is numbered according to the year and calendar month of the data collection period, for example 201912 corresponds to the UX data collected during December 2019 and would be released on the second Tuesday of January 2020 after the data collection period has ended.
In the list below, we've curated some release notes for each monthly dataset. Subscribe to our CrUX Announce mailing list or follow @ChromeUXReport on Twitter for release announcements.
202101
- Announcement
- Publication date
- February 10, 2021
- Notable stats
-
- 8,185,540 origins
- 23.71% of origins have good Core Web Vitals
202012
- Announcement
- Publication date
- January 12, 2021
- Notable stats
-
- 7,629,156 origins
- 23.4% of origins have good Core Web Vitals
202011
- Announcement
- Publication date
- December 8, 2020
- What's new
- As of December 3, PageSpeed Insights (web and API) is sourcing its field data from the CrUX API, bringing the tools closer in alignment.
- We rolled out a small accuracy improvement to metrics' 75th percentiles in the CrUX API.
- The API results were frozen for a few days at the end of November and the issue has since been fixed.
- Notable stats
-
- 7,942,408 origins
- 23.5% of origins have good Core Web Vitals
202010
- Announcement
- Publication date
- November 10, 2020
- What's new
-
A CLS issue in Chrome 86 may cause regressions in CLS scores:
Sites with absolutely positioned content with negative offsets outside the viewport will see large regressions in their Cumulative Layout Shift scores until the fix rolls out to stable.
- Notable stats
-
- 8,050,755 origins
- 23.7% of origins have good Core Web Vitals
202009
- Announcement
- Publication date
- October 13, 2020
- What's new
- No major changes in this release!
- Notable stats
-
- 7,937,088 origins
- 24.6% of origins have good Core Web Vitals
202008
- Announcement
- Publication date
- September 9, 2020
- What's new
- There was a bump in origin coverage this month (+3.3%) due in part to a data pipeline change. Previously, for a user experience record to be included in the dataset, it must have included FP, DCL, and OL measurements. Now, the only required metric is FCP. This change helps to ensure that we're capturing more meaningful user experiences.
- Notable stats
-
- 7,773,359 origins
- 24.9% of origins have good Core Web Vitals
202007
- Announcement
- Publication date
- August 11, 2020
- What's new
- No major changes in this release!
- Notable stats
-
- 7,527,878 origins
- 25.2% of origins have good Core Web Vitals
202006
- Announcement
- Publication date
- July 14, 2020
- What's new
- User experiences served from Google's AMP cache are now attributed to the publisher's origin in CrUX. Effects will vary depending on the amount of AMP cache traffic relative to the rest of the website, but most origins see less than a 5 percentage point change in Core Web Vitals performance, with most effects being positive.
- Notable stats
-
- 7,501,835 origins
- 25.34% of origins have good Core Web Vitals
202005
- Announcement
- Publication date
- June 9, 2020
- What's new
-
There were two
LCP updates,
which should have a minimal effect on most origins:
"Largest Contentful Paint measurement should stop at the first input or scroll on the page. In Chrome 83, inputs and scrolls in subframes were correctly accounted for."
"When comparing sizes of images for Largest Contentful Paint, the visual size of a background image was previously computed as the size of its Layout Object. This is not correct in all cases; for example in the case of CSS styles like :first-letter. This issue was fixed in Chrome 83."
-
There was one
FID update,
which may result in some sites observing faster FID experiences:
"In Chrome 83, a bug was fixed in the implementation of First Input Delay (FID). Prior to M83, First input delay values less than 1ms were not reported to the Chrome User Experience Report (CrUX)."
- Notable stats
-
- 7,103,486 origins
- 23.77% of origins have good Core Web Vitals
202004
- Announcement
- Publication date
- May 12, 2020
- What's new
- There was a small improvement to the way LCP is measured in M81. This may manifest itself in your CrUX data as a slight shift in slower LCP or in rare cases too few LCP samples to include for your origin.
- Introducing Web Vitals! CrUX is committed to providing you with all of your Core Web Vital metrics to give you an accurate picture of how real users experience the web.
- Do you query data on a per-country basis? Give the new experimental.country table a try! It's optimized to make querying across country and monthly datasets super easy.
- Notable stats
-
- 6,389,861 origins
202003
- Announcement
- Publication date
- April 14, 2020
- What's new
-
CLS histogram start/end values changed from
INT64
toNUMERIC
type and divided by 100. This change aligns CLS with the fractional layout shift values provided by the Layout Instability API. - Notable stats
-
- 5,937,298 origins
202002
- Publication date
- March 10, 2020
- Notable stats
-
- 6,366,736 origins
202001
- Publication date
- February 11, 2020
- What's new
- Experimental metric on notification permission acceptance rates
- Notable stats
-
- 5,976,293 origins
201912
- 5,532,155 origins
201911
- 5,821,306 origins
- the FID metric was moved from
experimental.first_input_delay
tofirst_input.delay
- the CLS metric was moved from
experimental.cumulative_layout_shift
tolayout_instability.cumulative_layout_shift
201910
- 5,752,729 origins
201909
- 6,008,004 origins
- the LCP metric was launched as
largest_contentful_paint
- CLS was updated to take
move distance
into account
- coverage may be lower while Chrome users upgrade to the latest version of the Layout Instability API
201908
- 6,011,463 origins
- FID coverage has returned to normal
- the average percent of fast experiences for most metrics dropped by about 2%
- this appears to be due to a bug in Chrome
201907
- 5,612,504 origins
- there was an incremental update to Chrome's FID implementation, which included pointer events on mobile
- coverage will be lower while Chrome users update to the latest version
201906
- 5,624,797 origins
- the TTFB metric was added to the list of experimental metrics as
experimental.time_to_first_byte
201905
- 5,884,155 origins
- the CLS metric was added to the list of experimental metrics as
experimental.cumulative_layout_shift
201904
- 5,744,982
- there was an incremental update to Chrome's FID implementation
- coverage will be lower while Chrome users update to the latest version
201903
- 5,703,255 origins
- there was an incremental update to Chrome's FID implementation
- coverage will be lower while Chrome users update to the latest version
201902
- 5,464,560 origins
201901
- 5,351,287 origins
201812
- 4,654,112 origins
201811
- 4,697,003 origins
201810
- 4,374,729 origins
201809
- 4,375,805 origins
201808
- 4,386,422 origins
- histogram bins have been normalized to consistent widths (more info)
201807
- 4,202,945 origins
201806
- 4,134,123 origins
- the FID metric was added to the list of experimental metrics as
experimental.first_input_delay
(learn more)
201805
- 4,162,633 origins
201804
- 3,970,181 origins
201803
- 3,589,954 origins
201802
- 3,237,524 origins
201801
- 3,086,603 origins
- added country dimension
201712
- 1,939,945 origins
201711
- 1,237,407 origins
- expanded dataset with 1M+ origins
201710
- 10,000 origins
- Chrome User Experience Report beta preview is launched at Chrome Dev Summit